Alesis QS8 Synthesizer Repair and Teardown

Repairing a neglected Alesis QS8 Synth. Some issues due to age and others due to water damage. Keyboard repair, dead keys, and LCD replacement are covered.

[@CorciPorci]

I respect people capable of fixing synths.

[@beebopcola]

I just got a QS6.1. This is so helpful! Good image quality, good viewpoints and detail shots. And some handy explanation as well. Thank you!

[@spike.jordan]

I stumbled across your channel for your drumulator teardown and it was super helpful. I've also got a QS8 with some dead keys that I'll tear apart one of these days and get back up to full working condition, but I just wanted to say thank you for being so in-depth and thorough on how to do all this stuff. You've got me set for anything I need, and I'm grateful.

[@mrz80]

Be prepared to take out A LOT of screws! :) And take some pics before you start pulling stuff apart.

[@icsnowman]

Great video. I bought my Alesis QS8 back around 1997. It's been a great synth and is built like a tank. If I ever need to do any repairs, I will go back and watch this video again.

[@davidbigda4663]

just bought one and can not believe there is a video like this one. thank you so much!

[@inkpapers-1]

I used to have one of these, it's really great to see inside one and see a restoration!

[@jatteriikonen]

great delivery and packed with some very useful info for us who appreciate & take care of these nowadays very underrated quality instruments, of which I personally own two, the newer qs6.1 and qs8.1 versions, both keepers as highly versatile and durable workhorses that have just a right combination of warmth and clarity that so many similar otherwise good & famous digital instruments lack - and the great unique fat rubber bend & modulation wheel design that I love for their grip and very precise feel over any other wheel design ever made

[@kevinfamous12]

Thank you for posting this! This helped me fix dead keys on my QS7

[@bienbalajadia8345]

tip: there is actually carbon paint you can buy off Amazon to repair carbon contacts. Much easier to use than donor contacts". You also won't need to mess with the correct height dimension as you most likely won't get perfect after cutting off the original.

[@BopsStudios]

I found it and fixed an MMT-8 unit.

[@GeorgiaFraietta]

Great vid. Had some keys not working on mine, gave the connections a clean but didn't help. Turns out the issue was a corroded circuit on the circuit board which was a simple fix with a bit of wire and solder to bypass the broken circuit. Fixed now :) Saved me a few hundred bucks on a new keyboard.

[@videosuperhighway7655]

I own a QS 8.1 still works great. Amazing that something 20 years old still works perfectly. I always wanted one in 99but could not afford it. Bought one on ebay for 500 buck with roadcase and it was practically new. Works great, and they dont make em like tanks anymore.

[@lyricsguruapp]

I printed the reference manual for the 8.1. In Part 8 (Editing Programs) it references a chart of Groups and Voices available in the device. I get how to toggle thru each main group number (e.g, 60) and toggle thru the subsets (e.g., 61, 62, 63...). However; I don't see how I can determine were the specific instrument/voice (e.g., is located on the keyboard. The group chart has a long text wrap of all the instruments (voices) in that group. Does this device's LED identify which voice is being used? I'm trying to find the following: [Group] Pecus [Voice] Cabasa, Clave 1, Clave 2 and Tambourine.

[@procta2343]

I do have a QS8.1, and its spot on! built like a brick shit house too! I have really need to start to learn to play it again.

[@rodolfonetto118]

How the keyboard action compares to more modern keyboards? Friends had the QS8 and I really liked the keyboard but it's been a while since I played it for the last time. Thanks! BTW, the keyboard is so respected I can find these rubber parts, new, even in Brazil!

[@CoeMusicStudio]

I've had this synth as my digital piano and MIDI controller since about 1997. It's been with me through college, grad school, all of my pro career and has moved with me to about 5 states (last I counted).

[@williamhogan2093]

really enjoyed teardown and sodering without cooking board! thanks

[@marshallherington4436]

I just picked up a very neglected QS8 at a garage sale. Power switch is missing, so I'll have to get that before I can even turn it on. I haven't opened it up yet, but it appears someone has in the past - several screws are missing or mismatched. Thanks for the really excellent tour of your work. With luck I'll be able to restore it to fully operating (if somewhat ugly looking) condition.

[@LeeHill1941]

QS 8, but do not know how to get in touch with a parts supplier. I am a pastor, retired former USAF Electronics Tech. internet: [e-mail] Thanks and Blessings, great presentation!

[@mrz80]

Next up on my workbench is a QS8.1 I found on Facebook Marketplace for [ridiculously low price redacted]. Seller said it wouldn't power on, something rattles around inside the case when you pick the instrument up (and imagine my surprise when I went to put it in my car and it weighs SIXTY POUNDS!?!?!), and someone spilled a can of house paint on the case. She just wanted the thing gone 'cause she got a new keyboard. THIS is gonna be a FUN one. Thank you for posting this video. I'll watch out for bad filter caps, and maybe see about putting a heat sink of some shape on that regulator.

[@mrz80]

Late update: aside from the yellow paint splattered on it, and one dead key, all that was wrong was the transformer board to main board jumper was disconnected. Reconnected it, powered it up, and it's alive! Now to take the contact board off the treble end and clean that dead key... I dunno what's more tedious, taking out all those little screws, or trying to get the little "feet" on the contact strips stuck back in all those holes in the contact circuit board. Meh! :D And finally: All back together and working great.

[@j.dragon651]

I have one I am going to have to work on and this video has been a great help.

[@AaronDengler]

Awesome instructional video. Really appreciate that you shared it. 🙏

[@metaspherz]

I still have my QS6.1 keyboard but it needs repairs. It was in storage for 15 years but when I tried to play it some keys were dead and the display was not working properly. It was one of my first synths along with the Korg N1. Sadly, it too is in disrepair with similar issues as the Alesis. They were all wrapped well and in their original boxes but storing them in a damp basement was not a good idea. Time and dampness took their toll for sure!

[@dailydreamer7584]

Very helpful video🙏

[@charliemirviss4608]

Brad, your videos are incredible. I have an 8.2 with only one channel and no MIDI. It's never been out of my studio, clean as a whistle. Could it be the battery, never replaced, or do you have other ideas of likely culprits? I'd really like to get it back to its original state. Thanks!

[@tripslip38]

You're awesome, man. Thanks for the preview of what I have to do to replace the display in my QS7. I bought it in 1997 and stored it in the attic the last few years. I think some super cold temps must have pooched the LCD. I chose that exact same light blue on dark for the replacement!

[@tripslip38]

A follow up... the display I bought from Jetpackmods had this piece on it that interfered with the QS display bezel. I had to do some careful surgery on the bezel to make it fit.

[@bming2]

Thanks!!! Replaced my display from this.

[@YTisverycool2007]

Hi Brad, thank you for your video. I too just got one QS8. However, the sound volume through the headset is very very low and there are no sound coming out of the two quarter inch outputs. Have tried the reset and same issues. I would be greatly appreciate it if you can give some suggestions as to how to troubleshoot this. Thank YOU in advance for your time/assistance!

[@AllenCook]

Brad, thanks for this video. I recently acquired a good condition QS7. The thing is, the display only show 8 of the 16 characters left to center! I opened it up and looks as if someone used what looks like hot glue to secure the display in place. The glue came off with a few gentle tugs and I was able to remove it. However this 'glue' is on the tape connector also. Looks like it'll come off so I can install another one. Not sure why only 8 characters, nor why the use of dabs of glue. Seems odd. I didn't notice any glue on your display, unless you removed it before recording that portion of the video. This keyboard is super easy to get into, unlike some other brands out there. Thanks again.

[@r19096]

Great vid Brad , Thanks for all the tips now I can try to fix one dead key on my Qs-7 I just picked up !!!

[@bradthx]

Thanks Bobby, glad you found it helpful!

[@jokeyman2943]

Excellent work, by the way.

[@jpenneymrcoin6851]

I have one of these, never figured out how to use all the synth stuff but it's a friggin tank

[@pablopicaro7649]

Good work on Old Equipment nov 2020

[@MGWGuitars]

I have an old QS8 - still works great. Just wondering, is there any way to reduce the tension on the keys? The hammer action is great, but it's a bit stiff (always has been). I'd love to be able to lighten the action, but I'm not sure if there's any way to adjust it on the inside.

[@AlbertJensen-uq1sy]

Recently bought a QS8 in kinda rough shape. Fortunately mostly mechanical issues. Your video was very helpful in solving these issues and I was able to get it in good clean working condition. Then I decided as a finishing touch to recap it. There was nothing to indicate this was necessary, just seemed like a good idea. Got it all done and...nothing. only the backlight on the display turns on. Restored the original caps, still nothing. Anyone got a hint beyond don't fix it if it aint broke?

[@boldcautionproductions9203]

Very cool, nice lab to work in. There is a QS8 on ebay right now, allegedly in good working order, tempted.

[@MidnightVisions]

@18:30 Don't rob a tv remote to repair the conductive rubber pads, just order a Keyboard Repair Kit off of ebay. Some kits include the silicone adhesive needed to glue the pads onto the rubber membrane.

[@iodinedesign]

Thanks for this video! Very helpful.

[@SHADOW4301]

Great video. Love my QS8. May replace the display based on your video, as it has a number of bad pixels.

[@audiosaucer2124]

@ 15:20 - My heart jumped a beat :O Nice video though :)

[@iShming]

I finally uncovered my missing sustain pedal! I was overjoyed. Then the wire just pulled right out of it. I can't find a screw hole or any way to open it up to fix it. I can't find a video either. Got any suggestions? Thanks much!! It's the "Foot Switch 93 Made In Italy by Fatar". UPDATE: Stick a screwdriver on the side near the hinge and pry. It pops off safely! :-D

[@ehenyor]

It looks like someone spilled a beer in there after a gig.

[@Arevirr1]

Man, I really enjoyed that! Thanks!

[@modularcodeswitching]

Hola, Brad! May you please can clarify how to rewire the LCD with 2x7 pins (original lcd) to newer ones with 1x16 pins? So I think it is like 1->1 till 14->14? Because the new design has separete pins 15 and 16 for LCD BACLKIGHT at 16 pins layout? Right? But you told about swapping data pins?

[@modularcodeswitching]

You can find the wire diagramm here: kzbin.info/www/bejne/jn2qioiurLSHq7c

[@stevejk9127]

Hey Brad, great vid, thx! Just unboxed my QS8.1 after moving and storing it a few years (orig packing, climate controlled). No visible external damage or corrosion, but L audio channel is now low volume and scratchy, on both the headphone and line outputs. R side is fine. Think that would be the Op Amp or one of the DACs, or maybe (hopefully) just a bad cap somewhere? I'm handy with a soldering iron if I can figure out what went bad...

[@bobrainy5324]

What is the exact White LCD you used and do you have a diagram for the wiring for it. Thank you very much!

[@KarenLCook4]

A couple of weeks ago, I noticed my QS8 tone was losing pitch. My husband and I took it apart after watching your very well done video. We cleaned it up, and it seemed to be working. Yesterday, I was playing it, and it died. I did the reset, and was able to play it again for a few seconds, and it died again. What do you suggest might be the problem?

[@marksmg]

Great video. I've had mine for 20+ years and love it. Only recently, the sound started warping - it sounds like I'm using the pitch/modulation wheels when I play the keys (but I'm not). Wondering if a cleaning would do, or is it a more complicated fix?

[@markfothebeast]

I'm not finding much information on the Alesis DG8 which appears similar in ways. I guess I'll just have to pull it apart and try the same method to fix the few poorly functioning keys.

[@markfothebeast]

So the DG8 is very similar other than it has an access panel on the bottom. The keyboard section comes right out the front after removing the screws holding it in - rather than having to disassemble everything. I thought I'd have to remove 100 screws but it was only like 12.

[@MrSquonkman]

Hi Brad, Great video! Is it possible to "chop" a Qs8 in order to lighten it up for portability? What parts are the heaviest? Do you know the weight of the keybed alone?

[@interrexclamacion]

Don't know if you'll see this, but I wanted advice. Recent got my hands on one of these and the LCD screen doesn't work; the backlight comes on, but it doesn't display anything, I don't know much about the electronics of these things, so I don't know how to fix it. I'm going to replace the battery and see if that helps, but is there anything that might cause this, and is there anyway I would be able to get a replacement part?

[@DICARLOPRODUCTIONS]

I was an Alesis endorser in 1996, and got one of the first ones shipped to Germany. The fuses were to weak in the first ones shipped to Europe, and it blew out almost immediately. They sent me another one with a stronger fuse, and that never happened again. Mine has never been out of my studio, so it´s in excellent physical condition. It just stopped working about 2 years ago. We were in the middle of a rehearsal, and suddenly there was no sound. We turned it off, and on a few times, had sound, but then it disappeared again. Then finally no sound at all. The Midi also doesn´t send a signal, so I can´t trigger sounds in my computer either. The LED stopped working at least 6 years ago. It lights up, but it´s blank. Nothing on it. I tried the Reset by holding down 0 and 3, and powering it on, but still no sound. I´ve read the LED is a common problem with the QS 8. I bought a new one on eBay, and will try to switch it out today. I want to change the battery, but can´t seem to get it out. I really don´t want to break anything. Usually these batteries just pop out. This one doesn´t. Also, what battery does it use? All my Roland V Drums, and SPD Pads use a standard CR 2032. The battery in the Alesis looks larger. If you could get back to in the next days it would be great. Thank you.

[@pablopicaro7649]

Just like in the Video, the Capacitors in Power Supply go bad. Most likely scenario.

[@chrisanderson208]

Excellent video, thanks for navigating and explaining the various chips. When I power up, my display shows some bars that then fade away, although the screen is still green. There is no musicl sound however when powering up or off there is the power surge click, so I'm confident the output to headphones is reliable. I checked the battery, it still has its charge. Do you have any ideas? power supply? Thanks

[@gregaudrey307]

I own a QS8 that I purchased new back in the day that still performs pretty well. Is there a fix for the clunky noise that the weighted keys make. I know that this is typical of most weighted keyboards, but I believe that after 22 years, mine have gotten much worse. Thanks.

[@j.dragon651]

Thanx, mine are now fixed. Can you split these keyboards. I can't find anything in the manual about splitting? Since I had mine apart I sanded down the ends and stained them. Made them looks almost new.

[@mikeh8047]

great video

[@stacymoroz]

Thanks! Very helpful. One of my Key pivots, I think sometimes referred to as keyclips broke. Any chance you could tell me how to remove the pin/rod that connects all the pivots?

[@theghostofsw6276]

Is there any way to actually "tune" a digital piano? I have an Alesis "Prestige" with 1 note (Low F2) that sounds annoyingly sharp...sort of like an upward pitch bend. There's a "tune" function for the whole keyboard, but none for individual notes (as far as I know from searching online). I was hoping there might be a way to physically adjust the notes....is there such a way? Thanks.

[@lyricsguruapp]

I printed the reference manual for the 8.1. In Part 8 (Editing Programs) it references a chart of Groups and Voices available in the device. I get how to toggle thru each main group number (e.g, 60) and toggle thru the subsets (e.g., 61, 62, 63...). However; I don't see how I can determine were the specific instrument/voice is located on the keyboard. The group chart has a long text wrap of all the instruments (voices) in that group. Does this device's LED identify which voice is being used? I'm trying to find the following: [Group] Pecus [Voice] Cabasa, Clave 1, Clave 2 and Tambourine.

[@Sheenaza]

Can you talk about how to fix the common pitch wheel problem these tend to have?

[@thehatchettman1]

Do you know of any audio issues that the Alesis QS 6.1 may have? I have two 6.1's that have the same left channel distortion.

[@scottsimpson8290]

The A below middle C is way too sensitive. Is there a quick, easy way to fix that? It's basically full volume at all times...

[@trippyafternoon]

Hey @bradthx what the green things called on holding the back side of the key one of mine broke

[@neilfahey3643]

I just found your site....I am in awe, to say the least! I have this same Alesis model, bought it about 5 yrs ago from a kybdst looking to upgrade. I had no idea of what I was getting. I am a pro drummer, but self taught on kybds, of which I do some composing/playing. The grand piano is what I mostly use, & the Fender Rhodes is very close to the original, I find. My Alesis is in bad shape, action is poor, one key doesn't work & it needs an overhaul. My question-where does one go-I live in W.Mass-& how much would it be to have a general overhaul done? Any help with info is greatly appreciated, neil fahey

[@Ifyouonlyknewtruth]

Thanks I fixed my Q7

[@bradthx]

Glad to hear, thanks for watching.

[@jansommer5409]

Hey Brad, Saw your video on the QS8, in search for a way to fix my QS8.1. I have no background in electronics, but was wondering if you were around SoCal and did that sort of thing? Hope you are well and thanks for the interesting videos.

[@andrewgjkgjk]

Brad, I have a QS8 that now outputs only white noise on the headphone/analog jack and I also tried connecting an optical to analog but got no sound. Any chance you want to take a look at it for me? How can I get in touch?

[@tiago4468]

Hi, i have a QS8...and i have a problem. Now, i turn on it and i get a blank display, just backlited and the unit is bricked. Before this, when it started properly, the display had writed ADDRESS ERROR and the keyboard got crashes randomically when i had selected some preset or plays the keys. Do you have any idea what can be? Although i have a Yamaha MOTIF, the QS was my first piano...and i would like to use it...I thanks if you can help me

[@MrLcdog393]

I need help diagnosing my problem with my Alesis QS7.. NO sound after a hard reset not sure what's wrong :(

[@DuroSamples]

I have the QS7 in my garage with a busted key and the pitchbend drifts off and detunes thesynth. WOuld like to fix it.

[@rodolfonetto118]

What is the material of those metal parts? That white gunk looks like mold - be careful.

[@kduane1]

I have one that has no response from the pitch and mod wheels and some of the FM type layer patches lose pitch. Any ideals?

[@joecarreiro4246]

Hi there my name joe i watched your video and i have the funny letters too on my display when i go to user banks but my concern i cand get global setting to get to keyboard mode to get midi on to use it as a controller ... have you ever ran into this situation.... any advice

[@jockeyshift4124]

Do you still have this synth? I got a line on one, power ,but no sound...If it happens I'll get back to ya for some tips and what to look for,definitely going to put in battery socket and do the cap upgrade as that may be my sound problem.I'm a piano player,so am lookin forward to doin camparison of the QS8, a rhodes and an acoustic baby grand.do you know if the QS7 had hammer type keys?

[@jockeyshift4124]

Finally got an 8.0 in trade for Korg Micro X and it came with a working parts machine.. wondered if you tried the toothpaste and peroxide on yellow keys... Anyone?

[@VanNguyen-yq8xy]

Hi, how can I replace new key? i can not dismantle the key in piano. Can you help me?

[@BopsStudios]

Have tried to replace the lcd, an a second hand display did not work......:(

[@whiskyboozer]

Help. I have a qs6 and I don’t know where to re plug the cables that video refers to as for the aftertouch. Any ideas as anyone. I can send a picture of my machine with the offending cables if that helps.

[@marcellolunnardibsantos2734]

Good job men!! How to contact you if I need to repair my 8.1??

[@kduane1]

My mod and pitch no longer work and the board is pitched up a whole step. Can i just disconnect that cable or board and return the unit to C and just not use these wheels? Anybody?

[@charlieconverse5572]

My unit won’t power on and while following along with your video I noticed the linear regulator was getting super hot... is this an indication that my keyboard is toast?

[@Yesterdays_Children]

Hey there, I have an Alesis QS 8.2. do you do service? I live in Southern Wisconsin. Advise

[@jokeyman2943]

Hello Brad, like to get in touch online-can share some of my repairs/mods for the Alesis Fusion, same TP40 as the QS8, and might have a few tech questions/answers. If you are interested-I am on the Alesis music group as Jokeyman.🙃Correcting this earlier post-I have a non-working QS 8 in front of me-it is a Fatar TP-20 in the QS-early Fusions used TP20's identical to this one, others went to the TP-40. Also with aftertouch, weighted non graded version, and what I believe would now be considered the TP-40L, as the action on the fusions is very light for a weighted 88-key.

[@AR-pb2zh]

Any tips on how to fix the keys? The green clips are starting to break and for now I glued one of them but it does not last. I read on a forum the clips were pretty cheap but I have no idea where I can find them

[@j.jwhitty5861]

Any ideas how to replace the lcd for an Alesis Quadrasynth (1992) S5, it has 14 pins plus 2 for back light.

[@putnee1]

great thank you

[@adonnimodeste8688]

I have an alesis coda with 3 dead keys. I tried cleaning the contacts and also swapping the signal bands but none of those resulted to a fix. Any suggestions?

[@fisherslawncareservicellc2252]

i have an Alesis QS7.1 that even after re initializing has a warbling sound while playing. Can you advise on what steps to take or what i can do about this? This sound happens without touching the modulation or pitch wheel. when i initialized i made sure to have the mod wheel all the way down and turned the power on while holding 0 and 3 down. thanks

[@emorrell4849]

hi I have a qs6.2 and the volume slider isn't working. if i jave it all the wau down i can barely hear it. if i slide it up just a little, it goes to its loudest level. theres no way to scale down the volume. do I need to buy another slider bed? or is there a way to fix the one I have. if you have any information it would greatly be appreciated.

[@Pan6888]

Hi i have a prob with my lcd on my Alesis QS 6 can you please let me know about which part i should look for ? i think it will be hard to get the original but another from another company with the same specs - same dimensions also - would be of great help. Thanks.

[@lochbonniefarm7844]

How do I replace a broken key. I got the rear of the key removed, but I can't get the front off

[@TheAHACollective]

My QS6 is out of tune. I remember having to tune it when I first purchased used almost 10 years ago. But cannot figure out how to tune. The middle C is currently in the A position.

[@bradthx]

I want to say it was in one of the menu's, would need to reference the manual for it. Also check your pitch bender. If that pot is going bad / dirty it can cause the whole synth to go off pitch.

[@JonahMobarak]

Alesis Quadrasynth Plus Piano

[@joecarreiro4246]

❤❤❤❤

[@sharethejourneyoffaith]

I have an 8.1. It's got several issues - some you covered here. I'm not a bench savvy guy, but would love to have this unit restored. Has a few button issues - might be able to clean them out. My LED screen is acting up = lighting is very dim and won't increase. Know anyone in the Charlotte NC area who works on these?

[@gregaudrey307]

I purchased a replacement display several years ago on ebay (I don't remember the seller) and installed it myself (pretty easy...I'm not a bench guy either). I'm still using it today.

[@AlexandreSSilva-lc8qe]

Boa noite! Você teria o esquema da placa do Alesis Qs 8.1? Obrigado!

[@joshuaweichel6251]

Hi, Brad. I have an Alesis QS 8.2 that has three descended keys. Any tips on how to fix those? Thank you!

[@AR-pb2zh]

I have a problem with this too on my QS8. I opened it up and mine are due to the plastic snaps breaking off. Over time, fatigue for these plastic parts being in tension eventually wear and they break. What I did as a temporary fix was to hot glue the key but it will eventually come loose as the surface contacts are too smooth. Going to have another shot at it.

[@andrewtibbetts9181]

Brad, I just bought a non working QS8 off Craigslist for $50. They stated that it was working before and then they went in to change a few keys, and didn’t work after. I plugged it in, and the lcd was dark. Turns out since the connectors aren’t keyed, they had plugged in the lcd board connector backwards. I plugged it back in the right way and the lcd lit but displayed nothing. I can’t get it to do anything. Even tried the 0 3 thing and nothing. Any ideas? Would really like to fix

[@mrz80]

Just came home with a $50.00 reported-dead QS8.1 off Facebook Mktplace. Seller said she'd lost the power cord (standard IEC computer cord, and I got a bzillion of those) and she thought she remembered there's no audio out. There's something loose and rattly. This should be a fun project to get going again, which 'll be a very nice complement to my tired old Keylab49. :)

[@AntonovichHicksenbrau]

I have an QS 8.2 I want to refurbish. Sounds great but lately - 90% of the time it sounds like it is Drunk... and the pitch and modulation wheels are a bit dodgy -

[@ankurrickdey1645]

Sir please make a video for replacement display of Roland xp 10...

[@ankurrickdey1645]

And lcd display connection diagram.

[@WenderReis]

What did you use to clean the plastic cover?

[@freestate6200]

Hammeraction? Where are the hammers? This Synth is basically empty inside.

[@vitorlerbom3904]

My problem is the sound NE5532D

[@jasonmiller8873]

Two of my keys stay down and won't go up

[@alexvela6717]

I f you expected how to change to the right key