Roland Clan Forums

No problem, hope you can get somewhere with it! I would say most likely you have a problem caused by corrosion, a broken trace or something, a failed solder joint due to corrosion, or a component that has corroded internally, or even a short somewhere due to uncleaned electrolyte. Otherwise I can on...

The site should work, I just downloaded the manual myself. First click this button: 1.jpg You will get a dialogue to sign up. Just close that. Then you will get this: Click the free download button: 2.jpg I assume at least you would need the CPU, RAM and ROM to have power. Corrosion if bad enough ca...

I would check all power supply voltages and any secondary regulators. You could be missing a voltage rail. Aside from that, it's possible that bad capacitors, a known problem, have corroded some traces in the CPU area and are preventing it from working. The service manual was posted by someone else ...

Do you have an oscilloscope? Put the piano into DAC test/calibrate mode and check the waveform. If it's messed up like the one I posted, you possibly have a DAC problem. For me it was open circuit resistor in the adjustment pot circuit due to corrosion from the leaking capacitors. But with enough co...

You shouldn't need a schematic, the capacitors have their values printed on them. If you do want a schematic you could buy one here: http://www.manuals.altervista.org/Servi ... anual.html I bought the manual for my KR-3500 there.

I can only speak for the KR3500 ... 10uF 25v is OK for most of them. Most are 10uF 16v and there are 4x 10uF 25v. With capacitors, you can use higher voltage rated ones as replacements so using a 25v rated one where a 16v one went is just fine. You can leave those ones in there. However, there are 9...

Unfortunately I have no experience with these, aside from repairing the one I mentioned, so I cannot say "oh sure, those problems are always caused by such-and-such going bad." for example, as is more often the case for example, in TV repair! However.... since these obviously have a known ...

For the record, I removed all the old capacitors, cleaned the board, installed new capacitors but still the left channel was bad with digital garbage noise. All voltage rails were all OK. Viewing on the oscilloscope during the sine wave test for the DAC MSB calibration (VR1 and VR2) I could see the ...

Never mind, bought a copy online.

I just got a KR-3500 with the capacitor issue, will be attempting a repair too. I can't say anything specific as I have not ordered the new capacitors or done any work\tests yet, but I would suggest some things: 1) Did you clean the old electrolyte off the board? If you leave it there, it could be c...

Just wondering if anyone here has a copy of the KR-3500 service manual - I was given one and would like to try and get it working properly. At the moment the audio is garbled. There are some leaking capacitors, and from what I have searched on Google, this is likely the problem. However some of the ...