[sdiy] Korg DW-8000 power supply help?

[Eric Frampton]

Resolved!

On Nov 3, 2010, at 1:43 PM, Harry Bissell wrote:

> ohmmeter across the power supply outputs... look for short circuits.
> 
> Suspect failed electrolytic caps...

then Andy Jury wrote:

> This PSU has two bridge rectifiers. One block device and another composing
> D8/9/11/12, so check these. Other suspects are IC1 and C11. Looks for dead

Bingo. It was C11, the electrolytic that comes right after the block bridge rectifier.

Interesting, I replaced that one cap and every rail came right back up. Re-connected the CPU board to the PSU, and one 5V supply immediately dropped to about 3.5V. Then, over the course of letting the machine sit for about a half hour, it kept rising until it finally settled at about 4.95V and remained there ever since. Might that be a result of bypass caps on that CPU board re-forming, or...? That was a new thing for me.

Thanks for the help, y'all.

Eric