Yamaha PSS-680 teardown and repair

I got this amazing little synth for just 7 bucks, but it did need some TLC!
Subscribe: www.youtube.co...

[@johanneshuth9424]

Thanks a million. Saved my father's synthesizer 🎉

[@rot_studios]

Awesome!

[@BarryRowlingsonBaz]

Bought one in about 1989 and I don't think I've ever taken it apart so great to see inside. Its multi-timbral over Midi so you can arrange bass, chords, lead and drums on separate sequencer tracks (think I had Steinberg Pro-24, and early Cubase on my Atari ST) and it does dynamic allocation to its 16 voices. The ST is in the attic, the 680 is in my music room :)

[@penfold7800]

The great thing about the Custom Drummer on this keyboard is You can select Any of the preset drum patterns and use that with Any of the Preset Chord sequences/styles. Nobody else seems to have noticed that. Most other keyboards in the PSS and PSR series won't let you do that.

[@rot_studios]

oh yeah that's defo a big bonus!

[@rfrayo_]

I love this keyboard. I got one off of ebay for $30 in 2007. Now they go for very expensive. I have the 570, 370, 680, 795, and VSS-200. I also have a Casio SK-200 and DM-100. I was just buying every $20 mini keys keyboard that I thought looked cool. I had a very small apartment and made burgers at Burger King back then, so these keyboards were what I could afford. I moved on to buying more powerful synthesizers, but still keep these. Those old "toy" keyboards do have some amazing sound potential. I have a Lexicon FX processor I put these through and it makes them sound amazing.

[@rot_studios]

I still want the VSS-200, it's funky :D And yes put 'em through some FX and you got some amazing sounds!

[@monx]

right on

[@penfold7800]

And don't forget that you can MIDI this keyboard to any other keyboard, like the PSS480 to get layered sounds. I have a PSS680, PSS51 and TG100 and connected together through midi and an audio mixer I can get a really lush sound combo.

[@0xABADCAFE]

Watching this persuaded me to get mine out of storage. At first I thought it was completely dead. Then I remembered I removed the speakers because it used to sit next to my CRT in my Amiga/OctaMED setup. Several of the front panel buttons aren't working properly, so I'll have to open it up one day when the kids aren't here.

[@rot_studios]

Sometimes you gotta make it fit, haha Revive it! It's worth it :)

[@kopisusu2000]

I have just acquired my pss-680 (finally, after 30 years of waiting), and I really need to fully clean it up. So, I came a cross this video. Thank you for sharing this video. Are you Dutch, Sir? If so, dank u wel voor de video!

[@rot_studios]

Hope you'll have fun with it :) En ja ik kom uit Nederland :P

[@frankkeunen8253]

@@rot_studios Hoi, wat een leuk filmpje! Ik had ook nog zo een PSS680 bij mijn moeder decennia lang werkloos op zolder staan (in 1988 nieuw aangeschaft) en voorzichtig aan de gang gemaakt: eerst 1 volt erop en dan iets meer om de elco's langzaam te formeren... maar die waren nog verrassend goed! Uiteindelijk 12V en hij draait hij weer zoals verwacht en inderdaad de drumpads geven op eentje na problemen. Het lijkt erop dat dat de enige is die geen zonlicht heeft gezien en de rest wel..... Ik heb nu bij TinyTronics een tube geleidende verf besteld, eens kijken of dat gaat werken en voor hoe lang het blijft hechten. De pads doen toch niks meer dus ik zal ze eerst ruw schuren voor een betere hechting (net als wanneer je een fietsband plakt) Inderdaad verwachtte ik al dat alu olie de PCB gaat beschadigen. We gaan het zien en anders misschien padjes bestellen bij Ali-express die verkoopt de geleidende padjes los.... Vriendelijke groeten, Frank Keunen.

[@Mind-your-own-beeswax]

Just got given one of these and had the same power issue as you. Lifted pad and dry solder joint were the issues. Only thing wrong with it is one of the drum pads doesn’t work for some reason

[@rot_studios]

have you checked the carbon contacts on the drum pads? those wear out after a while...

[@TrenchcoatSteve]

Thanks for this video. I need to fix the power jack on my PSS-680 then I can connect it to my Atari computer for MIDI sequencing.

[@rot_studios]

Nice setup :D

[@bloodyhell6378]

I have the same problem with the drum pads. They need a fresh coating of conact material or you can add graphite on the contacts with a soft pencil for a temporary fix.

[@rot_studios]

Those pads really are the worst aspect of this keyboard with how they wear out for everyone.

[@listenin007]

Is there coating for the contact material we can buy to fix the drum pads more permanently than using a pencil?

[@bestrickie2]

P.S If you put the keyboard through an EFX unit you’ll really enhance the sound with reverb and other EFX.

[@rot_studios]

Yup, I got two Digitech FX units that are excellent for this :)

[@bestrickie2]

Hi. I had one of these classic keyboards many years ago and I am looking for another one the same. The rubber pads tend to wear out after so many years which happened to my pss 680. I bought some new pads and it was like new but if you can improvise by putting something on the backs of the drum pads then why not?

[@rot_studios]

Yeah the rubber pads work now but aren't that great haha

[@0xABADCAFE]

I fixed the pads on my old 680 the same way about 20 years ago. The glue eventually fails and the foil ends up loose inside your keyboard, which is less than ideal

[@rot_studios]

Oh yeah, it's definitely a temp fix. Gonna need to open 'er up again when I got the time...

[@0xABADCAFE]

@@rot_studios are you aware of any issue with the signal to noise ratio on this keyboard? Mine always had significant amounts of noise in the background, which was noticeably worse with the stereo chorus effect enabled. I was never sure if it was just because it wasn't a professional device of if it had a defective amplifier.

[@MIK_F40]

All 680 & 780 models have that hussy hiss sound, some 780's also have a high pitched "eeeee" sound in the background as well. The built-in amp is crap and doesn't help but also it's a known issue that FM is some what noisy. Recording artists back in the day with a DX7 used to try all sorts of tricks to get rid of the huss. I believe there might be a way to get the sound to come out more directly from the chip or close to it to get a cleaner sound, might be a video on KZbin, some people do this mod to Sega Megadrives.

[@bradholy]

Hi, I'm having a problem where 6 of the keys (14 to19) don't sound and can't see any thing wrong inside, any ideas about that? thanks

[@rot_studios]

The keyboard uses a 11x6 scanning matrix, so perhaps one of the 11 return lines is broken. Check the PSS-780 service manual which includes the 680 as well. Page 46 in the PDF.

[@bradholy]

@@rot_studios Thanks for replying! the service manuals I found only go to page 12.. pss680 owners manual only goes to 45. do you happen to have a link?

[@rot_studios]

@@bradholy I've put it on my server: evilturtle.nl/projects/files/yamaha_pss-780_sm.pdf

[@Petebassclef]

Trying to identify 2 components. Someone used the wrong wall wart & fried a capacitor & diode at the input. Looks like filter components. I will replace hem if I can find new parts. Can anyone help please

[@rot_studios]

There's a noise filter on the DC input, consisting of two capacitors, two coils and a diode for polarity protection. (This circuit is before the power switch) And overvoltage could definitely fry those parts. Make sure to check the 5V rail after the repair in case the voltage regulator has taken a beating as well (TR1, a zener and some misc components). For reference check the PSS-780 service manual ;)

[@Petebassclef]

@@rot_studios thank you

[@moviebrain2008]

Hi! Serious problems with my 680... Need to make a full reset because the only thing functionally is the main keys, rythms, tones, memo & the rest of the keys still not working, but the procedure that describe the user manual doesn't working, any another idea??? Thanks a lot

[@rot_studios]

Sounds like a broken trace or broken solder joint, probably need to check the main IC, try following the traces that go to the non-working keys and see if you spot anything.

[@bestrickie2]

I think Yamah still have spare pads in stock or you could try to put something on the back f the pads. Have U put this keyboard through your effects units?

[@rot_studios]

ohh if I can get spares that would be cool, I would like to keep this thing as original as possible, since it's such a cool piece of gear. Yes, I have put it through the FX units and you can do some really cool stuff with that. Though so far I have mostly recorded and played with it without the effects as I do really like the "stock" sounds :)

[@synthguruji]

Hey I m having this pss680...I need its spare parts i.e. keys and rubber pads of keys which r not working and many of the drumpad sequencer internal board too....do uhh have any idea about spareparts plzzz help... Me

[@rot_studios]

Ebay would be your best option, sounds like a faulty chip or broken trace somewhere. See if you can get a second pss680 for cheap so you can swap out parts

[@Uterr]

Hi! So cool to see this video :) i just got same PSS-680, it had a lot of problems. First of all, it already had foil contacts, and pads on PCB was weared out because of this. Also, pads like very stiff and not responsive, i just cant x_x And also, what can you say about that midi software for controlling synt section? Are they giving additional options on top of build in? thank you

[@rot_studios]

Yeah those pads are not designed to last unfortunately :( I'm currently using two softwares: PSS Wave Editor and PSS EDIT. The latter one is a bit better with patch storage but the former one has more intuitive controls. And yeah they give you the ability to edit parameters that cannot usually be accessed (such as vibrato delay and intensity, detuning, etc...) thus giving you a lot more possibilities with sound creation. Both these softwares work through MIDI so you do need a MIDI interface (can be as cheap as $5).

[@Uterr]

DrummingEvil ah, i see, thank you :) what midi interface do you use? i ve seen a lot of comments against a cheap midi-usb, that they could be laggy, uncompatible etc

[@rot_studios]

@@Uterr It would be so nice if YT would give me reply notifications already... Well if it still helps: I was using the inbuild MIDI functionality of my soundcard (M-Audio back then), but I've used 3 very cheap MIDI-USB devices over the past years without issues so... should be fine?

[@IrvinPadillaWeltraum]

I got one for a decent price but one problem, the bend wheel doesn't work, do you know how to fix it or do you have any video or info? Thanks

[@rot_studios]

The bend wheel is a potentiometer (variable resistor) so either that is broken or one of the wires connecting it is broken. Both are very easy fixes. If it's not those things you could check the PCB for broken solder joints or traces. Also make sure to check the bend wheel setting, I remember it should be at least 1 semitone but not sure.

[@penfold7800]

I vaguely remember that the bend wheel is also used as a controller for some midi settings, so check what mode its set at.

[@Endwarpowers]

Thanks for this video! It’s an awesome keyboard. I have an issue with a high pitched interference, do you perhaps know how to remedy this?

[@rot_studios]

Could be a simple as switching the wall wart you are using, some can induce quite a bit of noise. I don't recall what kind of power regulation the keyboard uses, it could also be a component (filter cap?) is going bad there.

[@Endwarpowers]

@@rot_studios For sure, at first I thought the same but it’s something I’m getting with battery power as well. I am going to take the whole thing apart and give everything a good clean, that’s a start right? Other than that the whole piece is in rather good condition apart from a slightly loose key! What’s the filter cap?

[@penfold7800]

The FM oscillators will pick up interference from anything that produces a radio signal, like Bluetooth or a mobile phone. Also, try putting a loop magnet on the power supply lead.

[@masimkhanniazi]

Hi I have PSS 780 lying around for over 10 yrs, cleaned and switched on nice, but problem is it A10KX2 Potenciometer doesn't change volume and also lot of back ground noice and very less sound of key pressing on both built-in speakers as well as aux.. Does it mean i have to change Potenciometer?

[@rot_studios]

When moving the volume slider, does that create a lot of noise (like crackles etc)? Potentiometers tend to wear out or get dirty. It may very well be that you need to replace it, but try spraying a bit of contact cleaner in there, then move the slider back & forth a couple times. If that doesn't fix it, try replacing it.

[@masimkhanniazi]

@@rot_studios thank you for such a quick and deliberate reply.. Yes it was stuck initially, i cleaned it, but it is all rusty at the bottom.. Guess i need a replacement.. Hopefully I'll find one with matching dimensions

[@penfold7800]

If it's rusty, then it's possible someone spilt a drink in there, so I would check any other nearby components too, and check that the headphone socket disconnects properly when you pull the headphone plug out.

[@jheighten7568]

I have the same keyboard my mother bought it to me back in 1988 brand new and everything works fine except for I can hear a static sound from the speaker and I would like to know if you have any idea what can that be. Is the left one.

[@rot_studios]

Could be a filter or decoupling capacitor in the output circuit. Or the opamp/speaker amplifier is going bad. Hard to tell from here :)

[@bobbyvirk3843]

Hi my piano yamaha pss 680 produce buzz sounds how to solve this issue please help me thanks

[@rot_studios]

Is that like a low frequency hum-buzz or more high pitchy/noisy buzz?

[@bobbyvirk3843]

@@rot_studios hi its high pitch noise, when I increased volume then it's happened. If you have any solutions please let me know or send any video so I can fix by self thank a lot for your help

[@bnoyan]

Mine has the same issue. There is like a dog repellent sound going on in the background all the time. I wonder if there is a way of getting rid of that

[@Endwarpowers]

I’d really like a solution to this issue as well, I just want a clean signal out of this beast!

[@johns.5030]

Did any of you happen to find a PDF copy of the PSS-680 service manual? Been looking all over and can't find it. ;-(

[@rot_studios]

I'm not sure if such a thing exists, I gather these "toy" keyboards weren't worth the dedicated repair shops.

[@johns.5030]

actually they do exist. PSS 460, 480, 680... all have them. a quick google search will show you the PDFs. only thing is 680 is only on ebay and private distributors to purchase