Roland KC-500 No sound

[themusic]

I have a Roland KC-500 that seems to have a pre-amp issue. When I run a test tone of -10dbv I
get a faint signal. I also happen to have another KC-500 in working order. I took the good pre-amp thru the
power section of the bad 500 and it worked great. I've read previous threads but it only seem to address the
power amp section. I have schematic but could use some help...thanks

[52 Bill]

I took the good pre-amp thru the power section of the bad 500 and it worked great. I've read previous threads but it only seem to address the power amp section. I have schematic but could use some help...thanks

Did you try the reverse and take the "bad" preamp signal into the good power amp?

[Enzo]

And did you try a cord plugged from preamp out directly to power amp in? A sort of external bypass, if you will.

[mozwell]

ask & you shall receive

check the mute circuit around Q203, Q204, what voltage do you get on the collector of Q204, also anode & cathode of D204.
If you short Drain to Source of Q203 does the problem go away
Are all power supply rails good.
Is there DC on any op amp outputs

[mark]

Hi

I tried to download the circuit but the page just wen blank. Could I have a copy of e circuit diagram.

Mark

[Jazz P Bass]

ROLAND KC-500 Service Manual free download, schematics, eeprom, repair info for electronics