korg poly 800 not worth the cost to repair this vintage synthesiser MF#81

[@ScottsSynthStuff]

I know this sinking feeling, when you open up a synth and see a previous "repair" that has essentially destroyed it.

[@ThomasGrillo]

This was an excellent demonstration of how to recognize a permanently failed device. Thanks for sharing.

[@markusfuller]

ThankYou Thomas :-)

[@Dee_Just_Dee]

It's also a class act. Most people only want to show their successes.

[@Michael_Smith-Red_No.5]

I don't think you failed on this one, but the person who shoved an open-lead component through a board improperly certainly did. Still, it was great to see a classic cracked open for us to see.

[@BertGrink]

Yeah i agree; knowing when you're up against insurmountable odds, and realising you can't fix it is prudence, not failure

[@orbithesun1]

Why did you have to record Poly 800 program file from a computer on to a tape recorder, couldn't you have just played the file from computer directly into the synth?

[@ClayMann]

This was so sad. It's such a great keyboard, really well made for the time. Damn shame it got abused beyond cost effective repair.

[@yingtianfu]

It is great to understand when to stop repairing something rather than going at it forever. Great video! Thank you for sharing!

[@SteveShanafelt]

Definitely interesting. Watching your diagnostic process, even when the result is "Not worth it," was worth 16 minutes of my time.

[@markusfuller]

Thanks Steve

[@Pvaeerener]

It also means some self identification in my case as we used to repair computers some time ago and that is quite the same steps we would follow to track down errors in mainboards and stuff like that. Reminds me of good memories. Thank you, Markus. ☺

[@puffzewm7880]

One thing to check is the the presets are filled with scrambled data. If you go through the parameters you will probably see that some of them have values beyond their range or strange characters. When the RAM blocks have bad data written to them they can't be written over with the preset tape. I've had something similar happen and to fix it I went the Patch 11 and set all the values to the proper range then copied patch 11 to the other slots. After this procedure I was able to transfer the factory sounds from tape. Don't give up on it yet! Thanks for the vid.

[@markusfuller]

Thanks Puffin Thomas. I have put it away for a rainy day. but I will remember your advice if I ever get it back on my desk. Many thanks from markus

[@mraduanemc]

Wow. That's super interesting! I'm going to remember that for later.

[@zerozeroisland]

Another great video! even with 'failed' repairs, there's always something to learn! I had a similar thing happen with a Chroma Polaris that was given to me. Just too much damage, circuit boards cracked, covered in rust, lots of components had signs of having overheated/fried. :( such a shame. I still keep it around, even though it weighs a ton, because maybe someday i'll be able to salvage at least one or two components out of it...

[@kay_lpzw]

Hey - I've once received a poly800 that had a bunch of problems! But mine wasn't as done as yours. It is working but I had to swap the RAM for a timerkeeper to make programs "stick" and some other stuff. If you still have that synth, i'd love to buy a few parts of it. (Chorus Board, Filter IC and some more). In parts shipping costs to Germany should be bearable Btw. love your channel. I'm an electronic engineer with the habit of hoarding things that needs fixing so I know the excitement of diving into synths and drum machines.

[@GaitaPonto]

well it can synth a typewriter almost perfectly.

[@butcharmstrong9645]

I still have my Poly 800 that I purchased in 1984 and was excited to see this video. even tho mine isn't currently working either, I cant bear to "part" with it. It had the most lush sweet string sounds ever (that's what I wanted a synth for in the first place) and for such an inexpensive synth too. sorry that yours was actually DOA. I was so hoping to hear it again.

[@petercarrington948]

Love your videos, I find them very therapeutic 😂. Seriously, I really admire your electronic skills. Great stuff. We need more people like you who repair and don't just throw away!

[@andrewverran3498]

I recently found a little portable Sanyo radio/cassette player in my late mothers belongings, has mic, phones,dc and battery powered...gtreat to see there could possibly be a future use of the tape...YOU'RE use of that cassette tape spun me out to the max...GROOVY AS.

[@RothmanHarv]

Love those Marantz cassette recorders.

[@markusfuller]

I have had that for years and it always comes in handy at least once a year :-)

[@cybernitemusic]

Great channel mate. Watching your troubleshooting and steps involved help me out a lot in my self education. I’ve repaired some gear now.

[@jackdavies6821]

Love your videos Markus - thanks for doing them. By far some of the least intimidating tutorials for beginners :)

[@Eyepatchfilms]

I spent about 150 hours fixing a Poly61 that had battery damage and every cap had leaked. Then the power supply blew and killed a VCA. Still worth the effort to me after I got it all working again. With as many viewers as you have, might be worth it to fix and do a full atomohawk upgrade at the same time. I just wish the chassis on the Poly800 v1 wasn't so ugly.

[@markusfuller]

Hello. I would love to do a full repair of this but it would be expensive and take a lot of time and I work full time and can only do these videos in my spare time (which isn't very much time). It would take me months and the keyboard is only worth £150 in working order. it may cost me that just to fix it. so sorry but this will go into spare parts.

[@ArtMacabre197]

Tape loading reminds me a C64:)

[@skyprop]

My Moog Source

[@michaelbauers8800]

A great thing is that in 2016, there's so many new analog synths. There was a time when analog synths were probably perceived as in short supply, but I can't imagine anyone feels that way today.

[@markusfuller]

Hi Michael, I agree it seems theres a new analog every month at the moment.

[@bobbarcus8310]

I love my Poly 800 bought it new in Dec 1984 Still works perfect I took care of it No dust beer change inside battery 2 times I Never put the 6 batteries in to play remote They will ruin it they leak fast

[@markusfuller]

Yes it is a good synth and I feel sad that I could not save this one.

[@NutritionalZero]

Ah the Poly-800. The keyboard player in my longest surviving band had picked one up somewhere for a tenner or something. When the 80s revival hit and we figured we should have a synthesizer we put it in the rig. It was pretty unstable tuning-wise and we never made any headway programming it-the presets were always good enough for that new wave sound- but I'd love to find one of these cheap. Sometimes it's just perfect.

[@sootikins]

Love the sound of the data cassette playback! Brings back many strange memories... lol.

[@rot_studios]

ZX Spectrum? :D

[@markusfuller]

reminds me of the spectrum computers

[@sootikins]

I was actually thinking of a TS1000 (USA version of the ZX81)!

[@rot_studios]

Ah yes that one :) I live in Europe so those are very hard to get here. Got a ZX+ here.

[@egodeathbliss]

I owned one of these back in the early '80's...first MIDI synth....had the tape backup/load etc... The LED lights should not be flashing/scrolling in the display. Too bad it wasn't recoverable....thing these days is to be sure and recycle it for parts to help keep another one alive somewhere.

[@PatriotOnTour]

This effect comes from the Videocam, interfering with the multiplexed LED of the Display.

[@pontram]

Well a few years later (I wrote a comment 3 years ago) and they are 200-600 euros on ebay.

[@minorglitch01]

Wow, and I thought my Poly800 was bad! A previous owner tried to mod mine and totally botched it. Replaced a cap with the wrong value, left loose wires inside, left a switch with no wires connected to it, and that same protection diode in mine had dark black leads with huge blobs of solder on them. Fortunately I was able to fix everything up and it works perfectly. Definitely a happier ending then your Poly800!

[@BrooseWayniac]

I have 5 Mono D Batteries instead of a Buttonbattery and no Solderpoints in the middle of the Board like youve got there! Is this the Solution to Solder a ButtonBatterie upthere, so i dont need no 5 Mono Ds? Can anybody confirm?

[@dvamateur]

This is a beautiful Marantz tape machine!!! It fits so well aesthetically with the Korg Poly-800. I miss those type of things. There were some really beautiful products in the '80s. Can't forgive myself for giving away that gorgeous cream color Sony answering machine with two mini-tapes. It was beautiful. What do we have now? A plastic soap container type flat slab of things, most of them. Photo cameras and camcorders are still around, but writing is on the wall for those as well.

[@markusfuller]

I was at a car boot sale on sunday and there was a very large collection of quality cameras on sale. but the guy was selling then for £5 each and sadly sold none at all. they were olympus, Canon, Nicon's etc. such a pity really.

[@dvamateur]

I love Olympus and Pentax brands. Olympus is known for innovative cameras, usually smaller than the competition. And in case of Olympus, smaller was beautiful. Pentax made medium format cameras, which Canon or Nikon never seemed to have guts to make. By the way, I much appreciate that the Bitish and Australian pronounce Nikon correctly. Americans insist on mispronouncing Nikon all the time.

[@twkarches]

The keys are probably worth something for those with broken keys. I was given a Poly 800 which seems fine but has 2 broken keys.

[@erichkohl9317]

Oh man! Tomorrow I'm picking up a used Poly 800 mk2 from Guitar Center. The ad said "good condition." I sure hope it is!

[@MacXpert74]

I was wondering why you used the tape recorder? You could just directly plug the audio-output from the computer into the tape load input on the synth. I've done this with my JP-6. Works just fine.

[@annother3350]

The computer is in a different room?

[@JipBosch]

When the leads of that diode popped up I laughed so hard! It fried the circuit board.

[@snolan1990]

It's got to be worth more than a tenner in parts. The keys alone you could probably sell for a few pounds each. Only trouble is that obviously takes time.

[@gorillaau]

Plenty of scope to brain transplant it and turn it into a midi controller. For a tenner that keyboard is a bargain.

[@HaydenWinnett321]

I'm not sure about this, but I remember getting a korg poly 61 a while back off ebay and when I first turned it on, it did the exact same thing - TAPE over the LED display, weird little pops and clicks coming from playing the keys. I realized that I had it in tape mode - there is a switch on the back. Switched it off and it worked completely as it should have after that. Don't know if that would be the same case here or not.

[@edencane]

Excellent outcome hahaha... I have a poly 800 and an ex 800...! I loved my poly when I first bought it.... then I sold it... then later I bought another in quite good nick... You know the story lol... keep the great videos... always enjoyable...!

[@rot_studios]

Seeing those diode leads made me die a little inside, poor Korg!

[@markusfuller]

Yes I suddenly realised it was " Game over " when I saw the diode leads. Pity as these poly800s can sound quite good and I would love to have done the moogkiller circuit bending on this.

[@rot_studios]

Yeah, i would've loved to hear a composition on that, ah well. Can't all be winners :P

[@ferenctulics9688]

I'm sorry DrummingEvil, but I'm 110% sure those diode leads aren't from the Korg factory. Like markusfuller said, somebody else has already been in that keyboard... Nice keyboard..., I use to play with it in 1987 if I'm not mistaken..., nice memories....

[@Insaneloop]

I have the second version but to listen the presets after loading the sysex or the cassette .. you have to restart the synth :) Cheers!

[@synthartist69]

If it would have been a bad battery, the poly would have still worked immediately after reloading the presets. Only after turning the machine off, would the sounds be lost once again, hence you would be back to the strange noises or no sound. Great video, thank you for posting...

[@infindebula]

On the positive side, the cheaply made Poly 800 is far from rare. I've had about 5 of 'em over the years ... the last one I had wasn't making a sound so I sold it for 50 bucks. These days I keep company with a Poly-800-II, which is a much, much nicer instrument. In contrast to the original it has a handsome black enclosure, a filthy digital delay with modulation, programmable bass/treble EQ per patch, MIDI sysex, and the real kicker: exponential envelope curves (vs. linear on the original). So the mkII always sounds punchier, and has a more ethereal release stage - it's what the original should have been.

[@truthisheredealwiit952]

That chorus on the og though.

[@superskier2]

I used to have one of these years ago and the led displays were constant not cycling like on yours. The tape loading sequence brought back good memories...lol Pity its unrepairable but you were in for trouble with only 4 screws holding it together, but at 10 quid it was worth a punt. You certainly find these instruments, just need to find a Jupiter 8 for 50 quid now. Love your vlogs Markus.

[@markusfuller]

oh yes jupiter 8 for £50 now i would certainly have a go at that. :-)

[@gunnerhoward3134]

I used to love my poly 800, used to have one with reversed black and white keys.

[@YouTubeSupportTeams]

if i seen screws missing from any item i was going to repair i wouldn't even touch it, my shop rule, just not worth the hassle but i know you didn't realise of course. great vid btw

[@PTechnicalOriginal]

Big soft spot for the Poly 800 thanks, and don't feel no way. The numpti who was there before you, might as well have just shoved it in the bath. Can't save them all mate.

[@GeeksThroughoutTime]

Hi Markus, I wonder if you would do a tear down of a metal detector, and explain why there is such a difference in ability and cost between the high end and low end of the products.

[@Novous]

I have a Korg DW-6000 I purchased years ago with significant water damage (and possibly soda?). The whole metal bottom panel was significantly rusted out. My board looks eerily similar to yours inside! (Including the insane idea of directly soldering the CR2032 battery to the board, which means I've got to rig up a battery holder to fix it.) Any tips for diagnosing, cleaning up a Korg / analog synth with water damage? I tried cleaning with IPA but it couldn't get this white oxidation off. Even denatured alcohol wouldn't work no matter how hard I scrubbed, first with a tooth brush, then a harder brush. I found that a pencil eraser works! But it's almost impossible to clean between closely packed through-hole solder joints. I've never repaired a synth, so I welcome any tips you have in general! Thank you for your time!

[@markusfuller]

ouch it sounds like you have a long task ahead of you. if it was just alkaline from a battery then you would use white vinegar to neutralise it but water damage can be difficult as theres so many different ways it can wreck a board. some boards are a compressed paper but they tend to swell if damaged. im not sure what to say other than just keep going and clean best you can. Im sorry im not too helpful here but there is no guaranteed answer to the problem that will certainly work.

[@romansidler]

Beaten? Nope, you are not. It was just a wise decision NOT to repair this thing. Good learning experience for all watchers. Looking forward to your next video. Thanks for your work, highly appreciated👍🏼.

[@romansidler]

+HalfSpeedMastering Well well, it depends on the perspective: from an electronics point of view, it definitely makes noooo sense to repair it. From the perspective of waste, it may be another question...

[@Envinite]

@HalfSpeedMastering Assuming he's not on shitty country, he could just throw it in electronic waste bin.

[@bisnetodeportugues]

My Korg Poly 800. is short-circuited. I can't find the Chips and transistors. Greetings from Brazil.

[@markusfuller]

sorry i gave away the pieces of this one in the video a long time ago and there is nothing left from it. my apologies.

[@bisnetodeportugues]

@@markusfuller okay. Thank you.

[@yingtianfu]

Hello, I dont think you need to transfer the .wav file to tape. You can just plug it directly into the Korg poly 800 and it should work fine!

[@GrootsieTheDog]

What is the average cost of replacing a single encoder on a newer synth (Analog 4 MKII) thanks.

[@CoTeCiOtm]

It was awful to see that damn diode there! Probably a former owner of the synth, without knowing anything about electronics got told "just replace that diode and it should work". Well, if that didn't kill the keyboard, the gooey substance spill certainly did.

[@DrUmSensitive]

I've got two if those, one with reversed keys and one standard without the joystick. As with all my vintage Korg keyboards, unfortunately, the sound is either distorted or stops abruptly. Any ideas? Also, would you sell me that one for parts?

[@Insaneloop]

After the factory patches loaded in, it needs a reset to work! Cheers

[@balebu1]

I am the original owner of one and I still have it. It does not need a reset after I load factory patches.

[@nihonam]

Can You please make a tour on your house? I'm curious about your workshop and equipment, and audio bench and so on. It seems to be very special.

[@markusfuller]

Hi I dont think my house is anything interesting, all you see in the video is almost all the small workroom where I do all the video's from.other than what you see theres just a normal standard house (ok a few more keyboards here and there but they have all been in the videos) many thanks but I will certainly consider it for a future video.

[@nihonam]

Well, how about your audio rack ?

[@markusfuller]

Audio rack contains: Symetrix511A (noise reduction) . Behringer multicom pro & composer pro (both not in use anymore) - alesis midiverb4 - lexicon mx200 - aural exiter type c - and patchbay, but none have been used for a long time as the Allen & Heath QU-16 mixer now does all the work with its built in effects, EQs, compressors & gates etc. so the rack will eventually go. may keep the aural exiter though as it adds a little magic to a mix that cannot be explained. oh I just realised theres more racks under the desk.

[@arkangelct]

very good video, a question the stack is connected to R1 and D1?

[@Tranzphonic]

Dear Mister Fuller, I have a Roland JX-305 with a broken PLAY button. also, i have had problems with the memory becoming volatile. most recently, the drum track would not play in pattern mode. i did some kind of system check which resulted in the patterns/patches being erased! but the drum tracks work in pattern mode now. what would be your rate (from the US) to ship and repair? i fear battery acid has leaked onto the board but NEW memories seem to remain after factory reset?!?

[@markusfuller]

Hello. Im truly sorry but I only repair in my spare time as i have other work to do. plus there are things here that have waited for repair for over 6 months because i do not get enough time off to do them , therefore I must regretfully say I could not really take on a repair for you. if i had more time and this was my only job I would do it for you but that is not possible. my sincere apologies.

[@Tranzphonic]

+markusfuller I'm chuffed you would even respond 😀. Thanks anyway. If you ever get the chance to crack open a JX-305 I'd love to see it!

[@Masterpg2007]

Not sure if you will answer, but recently my keyboard keys started malfunctioning, I opened it and cleaned also used some graphite on the key and the circuit that was worn out. It fixed for 5 months, now I'm going to do that again, do you have any suggestion if I should do something different or something besides the graphite and cleaning?

[@markusfuller]

Hello, Its really only a temporary fix with the graphite. if possible you should try and get the replacement circuit board with the carbon tracks on it though I know how difficult that can be sometimes.

[@Masterpg2007]

markusfuller Thanks for the answer, I'm gonna do a little reasearch because I have no idea how use those, my city is pretty small and the eletronics guy had no idea how to fix it too.

[@ninnon354]

Markus, have you tried to play it from another midi keyboard and to play an external soundsource with this keyboard ? it could simply have the MIDI LOCAL parameter set on OFF... as much silly this can be, it happens sometimes...

[@markusfuller]

Hello yes you are right that can happen but in this case some major chips have been killed by the diode leads placed across the circuit board. plus i tested some and the oscilloscope shows they are dead.

[@ninnon354]

R.I.P.. then... :_(

[@geluix69]

Wow, brings back memories. My first real synth.

[@josephmills3864]

Cool video. Very realistic. You can't always hit a home run.

[@Tron1731]

this is a bad ass synth please look on e bay for parts you can start by cleaning all the pcb with dish soap look for bad caps and open parts the chip sets are basically indestructible unless someone pluged it in to a wall socket check out the demo on the poly 800 thanks for the video you are awesome to watch and a great tech @ never give up you can do it!

[@markusfuller]

Hi some of the chips were killed because of the diode wires placed across the board from underneath. this will be used for spares to hopefully repair others in the future.

[@formercakid]

I have a Poly 800 and it powers on but sounds seems distorted. Do you have any idea what is the problem?

[@annother3350]

Turn it down a little 😉👍🏽

[@МиланПавловић-ф3т]

That's sad. The sound of old synthesizer is unique and the best would be that this Korg functional.

[@markusfuller]

I do not think this one will ever work again but some of the parts may help others to work again.

[@clydesight]

I'm sorry that this was so badly treated before you found it. I've gotten some vintage tape recorders from E-Bay for my channel videos that have had similar "repairs", rendering the machines hopelessly useless! Maybe you can use the Korg for some parts? Thanks for posting your video! Also, I have a Juno 60 that does the tape load trick! I used a microcassette recorder and it worked just fine. The Juno is actually pre- MIDI!

[@markusfuller]

the poly800 has gone to the synthesiser graveyard in the back of my garage, but im sure parts will be donated over time.

[@QrchackOfficial]

Judging by poor job on the reverse polarity protection, battery getting warm, +4VDC on the output and the voltage regulator being too hot to touch... why didn't you check for a short on the power input first?

[@adamc1764]

Hi ok no problem, any advice at all do you know if they have a fuse?

[@markusfuller]

Hello Adam. I did not see any type of fuse inside this keyboard. I have read that many of them suffered faults with the power regulator so if that has died there would be nothing on the display at all. but they can be replaced and if you are lucky that may be the only fault.

[@alexprestin1293]

There would've been a battery on the board originally (on the two pads you point out at the beginning), but those old Korgs had a bad reputation for the batteries eventually rupturing and etching away the entire board along with the components. That's what happened here too.

[@klompjes002]

my first 8 keys works ongly when i hold the first key what you think is wrong ?korg i3 old

[@ElectricApe]

Hi Markus. Excellent vid as usual. One quickie: why did you do DAW -> tape -> Poly rather than just DAW -> Poly?

[@markusfuller]

to be honest I tried both ways. both came up with GOOD in the display but i kept the part with cassette tape in the video as it was more old school style.

[@ElectricApe]

+markusfuller makes sense! Cheers

[@Sonikbytes]

good timing on the video. I just got poly mk2 last week for repair. luckily mine had 2 broken keys and leaking battery which I fixed already. lol that tape player probably cost lot more than the synth!

[@markusfuller]

brilliant im pleased you got yours working. best wishes from markus.

[@andrewscott1253]

IS there a switch on the back? The poly 61 has a mode switch on the back.

[@MarctheDarc]

I would not toss it, but rather look around for another that goes cheap, particularly if you can find 1 that seems to only have external damage, i.e. makes sound just fine but are kinda messed up. Would probably be fairly easy to combine the 2 for a fully working package. Btw. isn't that small battery supposed to a "special" rechargeable 1? I could be wrong, but pretty sure they used rechargeable batteries back in the day, which is why it would last fairly long when used regularly. Modern batteries like that aren't rechargeable unless you find special ones that are (obviously). So while they fit and have the correct current etc. when the synth tries to charge it, it gets extremely hot and can explode. So if the previous owner used a standard battery when making that mod, it could have exploded all over the insides, hence it looks like there's been battery acid all over. Otherwise the brown sticky dust is often from the home of a smoker. It leaves this weird brown tar-like substance everywhere that connects with the dust. I've seen some pretty bad cases when working on computers, and while disgusting and clogging up fans etc. it doesn't seem to conduct. Thanks and good luck :-)

[@markusfuller]

Hi Marc I do think you have a good idea there about the battery exploding in the past and maybe getting onto the board. that could certainly explain a few things. I will not throw it out but will most likely add it to the synth graveyard in my garage. but thanks for your suggestion its something I never even thought about. Best wishes from Markus.

[@traumaduo]

PS: you could also Play the preset file directly from your Computer into the poly800. are sure the Memory protection is not enabled? when Memory protection is on is says "good" after loading file, but the Memory can't be overwritten and still no Sound Comes out...so on the back there is a Switch...try that one...and if not just try to Programm a Sound with the Parameters...

[@markusfuller]

Hello I tried the memory protect both ways. plus I know about the audio direct as theres many people already commented about it. but I wanted to use the cassette method just like it was done in the vintage days. but thanks anyway.

[@Slider2732]

Coca-Cola or beer... mmm hmmmm, I think you've found the beginning of the history. The case looks quite nice, so the best for this synth might be to find another with broken keys, or a cracked sideplate etc and swap it over.

[@instrumentalistjade8367]

Mine doesnt have a presets anymore? so im using it now as a midi controller

[@6or7breadsticks]

what did you do with the broken one? I wnat to fix it!

[@waheex]

I managed to dump mine straight from the computer line out, but the cassette is the business!

[@apemoth]

Stumbled across this video - I met you a few months ago when I brought the Waldorf streichfett! Don't suppose you want to fix my Poly 800 with the bits from this one? 😀

[@markusfuller]

If only I had more time to do repair work I would. trouble is I have so many things here waiting to be repaired already. some have been waiting for a year. I just really cannot find the time but if you know someone who can fix it for you then there may be some spares i can help you out with.

[@HyperdrivenPictures]

How devastating! First time I've seen you beaten! I have a Korg Poly 800 and the battery has gone. It had been in storage for nearly two decades, so easy to understand why! I also found the 'tape' audio file, but you don't need to record it to a cassette - my Poly 800 restored beautifully just using the headphone socket on my PC.

[@markusfuller]

Hello I had several days working on this poly800 and tried my best not to give up too easily but after finding the main chip was dead along with a few others I realised I would never get it to sing again. Yes I could have used the headphone out from the PC but I wanted to do it old school style :-) Many thanks from Markus.

[@HyperdrivenPictures]

Perhaps worth hanging on to? Maybe you might pick up another you can cannibalise?

[@markusfuller]

oh I will not throw it away, just incase the parts are needed for another one in the future.

[@sneezer7972]

What speakers would it need I have one too

[@emerson1978365]

Hi markus!!! Nice to meet you!!! I have since a long time ago a second hand Roland JV-80. When I buyed it (pretty inexperienced at that time) it arrived to me with no data on its memory because the original battery was out of charge. The original owner did replaced it but leaved the instrument with no data. From that time I used the instrument with my own sounds, Because it works and sounds very good, but I would want to recover the original data. Is it any Expansion cards for this situation or downloadable data from the web? I love your videos and your help. Please tell me what do you think. Cheers from Argentina

[@markusfuller]

Hello Emerson. hold down the number 8 button and turn on the JV-80 (keep this button pressed down while turning on.) then you should get a (factory reset) appear in the screen. then let go of the 8 button and press the ENTER button. that should set the unit back to the original settings in a few moments as if you just purchased it from new. I hope this helps. Best wishes from Markus.

[@PrinceWesterburg]

Did you try actually soldering in the diode? Its leads would be carrying half wave rectified AC to whatever it was touching, hence the 4v (4.5v?) DC on the output and overheating regulator. Take the board out, wash it and leave it in the sun / on a radiator for a day. Don't tell me you threw this keyboard out, probably nothing wrong with it!

[@Cincinnatijames]

I noticed when you went to tape load, you didn't mention turning the memory protection off. If the memory protection is on, the tape won't load, even if the tape load appears to be working correctly.

[@markusfuller]

Hi James. sorry you are right I should have mentioned that to people but can never remember to cover all the important things like what you have just said. thanks for pointing that out.

[@meatsock]

nice video, i'm a big fan. for what it's worth you can load the preset sounds directly off the computer, without going to cassette in between. keep up the good work!

[@markusfuller]

Thanks Peter, I was just trying to do it old school style

[@K.Psomiadis]

My Fist Synthesizer !! My Big Love !! I have sale it to buy the korg M1 and after that i have see that the M1 can.t play this analog sounds :)

[@demoscenes]

Can't be a winner all the time but you did try and that is what counts :) Go get them next time tiger. Really nice video anyhow.

[@markusfuller]

ThankYou very much. I hate to be beaten but it has to happen occasionally. Many thanks from Markus

[@otherunicorn]

I do hope you disposed of it in such a way as a third person won't try to fix it. I had a Seil Synth that had a failed voltage regulator dumping overvoltage through the entire logic board. As soon as I found that, I dumped it too. I also had overvoltage on a VCS-3. That one I fixed!

[@markusfuller]

Hi I have kept it in the garage for possible parts donations. it is in no condition for someone else to try and fix. (oh the VCS-3 wow what an amazing synth to have, thumbs up to you )

[@kevincozens6837]

The first thing to do is properly solder the diode in place and clip its leads. The second thing is to measure the voltage coming out of the regulators. That one that is very hot might normally be hot or something on that power rail may be partially or fully shorted. It could be fun trying to pin down if there is some simple problem that can be fixed.

[@radlers]

I had a poly 800 that was junky and the battery had fermented all over the board. Lucky for me, nothing was ruined and I was able to clean it up.. The batteries for those actually had stand offs to hover over the board (hard to find). Sad state this one...

[@markusfuller]

I find white vinegar is great for removing battery acid ( well its actually Alkaline so the vinegar cancels it out) My poly 800 was donated to a viewer who has used parts to repair his so all is not lost. Best wishes from Markus

[@radlers]

Vinegar rules for cleaning! Cheers! Enjoyed your video.

[@kletsgoo]

Would be interesting to take out the NJM2069 Filter IC, it's a very nice unit!

[@markusfuller]

sorry but I already passed this on to one of my subscribers as he needed the parts to fix his poly-800. but yes there are some interesting chips in that unit.

[@Pamberjack_]

In my experience, you can just play the sounds directly from yr computer into the synth. While the tape part is very cool to watch, it's not a necessary step.

[@HarryAxten]

As others have said, you can't win them all! You have a very early Poly-800 there - the first batch didn't come with the internal backup battery fitted and instead relied on the main power batteries to store patches. I guess you could part it out and still make your £10 investment back quite easily :-)

[@markusfuller]

I guess there will be someone out there who needs something from it to fix theirs. Im happy to be an organ or keyboard donor if anyone needs any parts from it.

[@organfairy]

And that missing backup battery was my luck: I bought a Poly-800 from a flea market for the equivalent of 5£. They thought it was broken but it turned out that it had just lost it's presets which will make it all silent untill it is reprogrammed or have the tape backup loaded. The D-type batteries inside was 23 years old....

[@markusfuller]

I too was hoping that a factory reset would be the easy Fix. I'm pleased you got yours working. best wishes from one of your fans :-)

[@philipharrell549]

I wanted what would be better the yamaha dx7 or the korg poly 800

[@jupitermarx]

I'd love for you to break down a Alesis A6 Andromdea? I have one and started to take it apart but was very concerned about breaking the end caps, so I put all the screws back in and decided it might be better if I could watch how a professional would do it?

[@markusfuller]

If I ever get one I will certainly do a teardown :-)

[@jupitermarx]

Thanks so much! I really appreciate you responding to my question. I hope it's soon! I watch all your videos and you have a fan here in Raleigh NC USA

[@markusfuller]

Thanks Mark . much appreciated :-)

[@cfcreative1]

Actually i fixed a few of these they play dead when the battery dies. Then you can restore them with a wav file you can download online and play into the tape input. Then they work like new. But they are a pretty basic analog synth to start with.

[@SamLowryDZ-015]

Sticky brownish dust = dope smoker residue. Causes chips to over heat and fry

[@stumeek6825]

Just like to mention, i`m a fairly new subscriber to your channel, i found that video utterly fascinating I`m hooked brilliant stuff sir!!!!!

[@adamc1764]

Always enjoy these videos thanks Markus! I have a doepfer dark time sequencer that stopped working recently, please respond with your rates and if you'd be interested in featuring it as a repair vid.

[@markusfuller]

Hi Adam, sorry but I am so busy I dare not take on more work as there are repair jobs under my desk that have been waiting a year for me to look into them. I just do not get enough free time from my normal job.

[@daftdj123]

Why did you use a cassette recorder instead of playing the WAV file directly from your computer... !?

[@markusfuller]

Hello Its all in the description below the video, plus I mentioned the DAW way about 50 seconds into the video. I did try this several ways but thought the cassette version looked better for the final video. many thanks from markus

[@floris1200]

nice vid but i had the same problem and weird voltages everywhere which can mislead you a lot. i replaced the voltage regulator and it work fine again

[@edgeeffect]

Couldn't you play the audio straight from your soundcard to the cassette port?

[@markusfuller]

Yes you can but I wanted to do it the old fashioned way with a cassette. like the good old days :-)

[@edgeeffect]

The way God intended! ;)