Hi!
I just got myself another broken Poly-800. (The first one I got is now beyond repair. As I was
offered a second one. I thought: Two minus makes a plus..). But now, after picking the new
one appart. It seems like the -5V circuit is broken. I've replaced Q18. But the only reading i
get is +0.9V where it should be -5V.
Could it be that small transformer that's busted? (KD-4? xD-4? It's hard to read the name on
the schematics. And it says T1 on the circuitboard). The output of it is +0.45V (Measured at
leg 1 of D10), I asume it shoudl be -2.50V instead?
Any ideas on how to replace it?
The long way, I guess, is to replace the entire circuit with a AC-DC converter that takes 9VAC
in and with a 7805 and a 7905 regulates it.. But it seems like to much trouble right now.. Or?
Thanks!
//Jon
Message
Re: [korgpolyex] Not getting -5V?
2008-01-13 by Marcus Wilson
in my earlier email, I suggest to replace Q1 and Q3 also
ensure they are the right way around, and see if that helps
I also gave part numbers for those
best regards,
Marcus Wilson
On 13/01/2008, at 8:19 PM, Jon wrote: