I literally burned my mind with this , so I decided to take a few months off before attempting to repair it again.
Dont throw the towel yet , I can help.
If you ever give up and decide to sell it for parts, please let me know because I am looking for some parts .
thanks

Hi buddy, you can find everything here . this one has been the most difficult repair I have ever worked on. If you are lucky it is just the spsu. In my case , I have removed all logic ICs, I have found 1 dead , replaced it but it is still not working. My thoughts are on the RAM and CPU but i havent ...

Hi VSErs :) I have a problem with a SH-09, when amp release is used , during the release stage the pitch drops. The synth works ok for 1 minute when it is cold, but after that period the problem appears. Also , when the synth is controlled by external CV, it is working ok. All these symptoms made me...

Hi ,
The problem could be the psu but there is a chance that a component on the mainboard is failing short dragging the positive analog power line down.
My bet is that the filtering cap at the end of the psu 12v line needs replacing.
Sorry i am on vacation and i dont have access to schematics

You should be proud of your Dad, thanks for letting us know
Obviously, the problematic chip was a 4051 analog switch that was routing signals from the CPU to the voices circuit.

Hi,
clean the potentiometer inside the pitch wheel assembly with a contacts cleaner or replace the potentiometer.
Also check the spring, the wheel might not center properly.

eirianwhopkins wrote: ↑

Tue Jul 07, 2020 4:00 pm

Recently bought a Roland U20 in need of some TLC. Fixed keys...

When you fixed the keys , could it be that you disconnected accidentally the ribbon extension on the left side?
This connection is not meant to be disconnected, it is held by conductive adhesive tape that is not reusable.

Hi, it looks like memory corruption.
if restoring to factory defaults does not help, check the power supply.
Also check for battery leakage as this could affect backup memory operation.
I have seen ram chips go bad on the mkI, causing similar issues.

Hi , what you are experiencing is a common issue for the D50. The problem is that the rubber contact strips that are under the keys , are either dirty, worn, torn or misaligned. https://www.synth-parts.com/media/image/f1/88/30/Contactrubber_Kawai_RH88Ag4Cf1ikGwcP7U.webp In most cases they are just d...

Sorry there is no way, you have to either use a factory card or send the factory sysex via midi

Hi and welcome to the forum.
The noise that you are describing could be a common issue for the M1.
A capacitor in the power supply and a resistor on the DAC board could be the culprit.
check this thread:
http://forum.vintagesynth.com/viewtopic.php?t=53799

Hi and welcome to the forum. The RFX32 card was optional and it was introduced with the ultra series. It needs at least EOS 4.5 to operate. For more info here is the cards manual: http://www.deepsonic.ch/deep/docs_manuals/e-mu_eos_6864_rfxcardinstall-c.pdf The differences are in the eos versions , t...

Did you try a factory reset ? Hold Int, Combi and Prog while turning it on.
Warning! all patches / settings will be lost .

Wow, thanks! Was your thinkning that the switch mode would not need hole to be drilled? Unfortunately , both solutions will need some hole drilling, it is just that the SMPS is easier to find than the custom transformer. Assuming that you live in the US , you can have a look for the custom transfor...

Hi , I have never seen a drumtraks in real life, but the transformer you are looking for has dual center-tapped secondary windings that output 2 x 18 VAC and 2 x 9 VAC, and it should be rated at 75 watts or more. Chances for finding the same transformer are slim , you can order a custom one with thi...