Roland XP-50.
Surface mount electrolyte caps leak , corroding pcb tracks on their way.
Classic symptoms: No Display, no output, battery low 0V.
I have one in front of me, I have replaced all electrolytes, jumpered 2 pcb tracks and it still does not work.

It is not a synth module , it is a custom midi system made by YES Audio or Alyseum, as pflosi points out in his post here:
viewtopic.php?t=93166

I think that they use graphite for making contact because if they have used copper, the keys could cause double triggering. In the past I have used caikote 44 which is very conductive , and I experienced the double triggering problem. Anyways, i am glad you did not follow my advice and got it sorted...

It is quite a fiddly job but I am quite sure it will work.

Let us know how it goes , good luck man!

hi Mooger5, I am no expert and I have never laid my hands on a dx100 but I have been in similar situation with many keyboards. Judging from personal experience, it is the graphite on the pcb contacts that is worn out. I dont like spraying graphite directly to contacts , usually i spray on a piece of...

I am no sh101 expert , but I agree with Mooger5 and meatballfulton. With discoloration happening to the Sh101 plastic cases , white sh101s should have turned yellow by now, just like the green/khaki and the light red/pink discolored units. All whites I have seen in pictures are milky white, so they ...

So it was IC1! I wish i had such luck with my own repairs...
What about the bender's range issue?

Unfortunately, the Chorus circuit doesn't work. I get crackling on Chorus 1 and almost no chorus on Chorus 2. Wild guess here, test or replace TL062 (IC1) on Jacks board, it could be the culprit. Also strange is the behaviour of the bender. I've bought a replacement bender pot from Syntaur but it s...

Haha ! I had no idea that it was so heavy!

It definitely looks like a casio CZ-1 , but I have my doubts if it has been used in the production. In the video only the front persons appear and not the real producers, so they could have brought anything ( the less heavy gear) during the shootings. It is also worth looking for gear list from T99 ...

Hi LT , you should confirm that you are getting +15v / -15v on the jack board. Sounds like wiring problem , have you tested the wires and connectors to the jack board for continuity? you can built a signal tracer like this : http://musicfromouterspace.com/analogsynth_new/HOT_TIPS/images/amp_signal_t...

Good luck LT, let us know how it goes !

Hi mooger5, I have to admit that yesterday I read your last post over 20 times, I was trying hard to understand what happens to the signal, but I was feeling too damn because I could not get it right. Today , after you edited/corrected your last post about C13 and C14, it is crystal clear now. ( one...

It makes more sense now, many thanks and sorry for distracting you from your work. Whenever your can, could you please explain how did you come up with the 44n value ? According to 2nd schematics that i have posted , I thought that If use a 47n for C14 the lower range will drop from 250Hz to 25Hz.

Hi Mooger5 and thank you for the help, I deeply appreciate it. Is C13 affecting the lower or upper range? Or am I oversimplifying things ? Interestingly, I have another parametric eq schematic with 2 bands, same topology as the previous one but with different ranges. Here it is : https://i.ibb.co/6y...