Korg Poly800/EX800 Users

On 29/07/12 10:32, kjelle.vergauwe wrote:
> I'm not really good with a multimeter, but....
> Just tested the Diode. I'm measuring 587 and 1. No beep though.

A "1" in the left-most digit of the display?  That means "infinite". 
Those readings look pretty healthy.

> Also noticed when measuring that the wires from the diode are black, I could scrape black dust off of it. (see picture)
>
> http://dl.dropbox.com/u/7760238/poly%20800/Diode.JPG
>

That's just the plating getting oxidised, it's normal.

Refer to page 1 in the diagrams I linked to in my previous post, bottom 
left corner.

With the AC adaptor plugged in and the power switch on, measure the 
voltage across C3 (little disc ceramic capacitor) or C4 (one of the 
three electrolytics near there).  You should see about 9V.  If not, 
measure the voltage between the positive side of C4 and the middle leg 
of Q1 (2SB744).  You should see whatever voltage the PSU is putting out.

You may need to remove Q1 from the board to test it, but I bet that's 
what the fault is.  If you're not comfortable with soldering and 
desoldering, then find some friendly neighbourhood electronics geek to 
help you ;-)

-- 
Gordonjcp MM0YEQ