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

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

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

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.

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...

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

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

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

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.

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

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.

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.

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!

Love those Marantz cassette recorders.

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.

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.

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

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...!

well it can synth a typewriter almost perfectly.

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.

awesome video! this is real quality programming. Keep up your videos, they're great!

Tape loading reminds me a C64:)

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!!!!!

Wow, brings back memories. My first real synth.

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

thanks for your effort! very helpful, one can learn a lot from it!

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.

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

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.

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!

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.

Thanks for another interesting vid, you didn't waste your time. You clever dude. Cheers mate xx

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

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.

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.

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.

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.

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

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!

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.

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

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.

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!

What speakers would it need I have one too

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...

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 :)

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.

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!

great video Mr.!

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.

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!

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!

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

Love your videos!

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

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

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

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.

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

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

why can you not just record from a wav file [8bit 8kHz] on your pc and run a cable from the pc sound card 'audio out' into the 'tape in' on the poly-800?

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

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?

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

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

Hola. Tengo un korg poly 800. Quería saber como calibrar los 3 potenciometros que están juntos en una placa aisladas. Ya que accidentalmente lo giré. Agradeceré su ayuda.

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.

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?

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

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.

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

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.

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

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.

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!

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.

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

@10:10 "Ooh My my my. What the hell is this!" Loved it! ;-)

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

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!

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

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

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.

I think somebody originally had the DC power input polarity the wrong way round and that protection diode would have blown o/c so will caused damaged to IC's not repairable now

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?

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!

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

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.

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.

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?!?

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?

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?

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...

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 :-)

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...

love these videos. can you open up other then musical equipment :P?

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...

That's a pity. I really like the sound of this rig. 3:45 lol

I have a poly ex-800 sound module, battery is dead and I would get just white noise sounds. I had to write all the sounds from scratch and save them or just leave it on. The battery was always an issue. Fortuneately its the easiest old module to write to Mine is still working but the display is hoopy an led is out. The old polysix keyboard was a beauty it was blue and black lots of knobs no midi? That was a vintage keyboard worth saving, alas it did not happen

Is the (non-chargable litium!) battery directly wired to the power supply jack?? m(

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