Archive of the former Yahoo!Groups mailing list: Korg Poly800/EX800 Users
Subject: Repairing an EX-800
From: "Alexandre Souza" <alexandre-listas@...>
Date: 2009-01-09
Hi you all, maybe someone could lend a hand here.
I have an old EX-800 which I want to revive. It was connected to a 220V
mains, blowing something inside. I got it already messed, but not that much.
Seems 3 transistors were changed, and a zener. But the transistors are not
original and the zener is unreadable. Also, the only schematic I got access
is incomplete and very hard to read.
So, if anyone is willing to open up his/her gear and take a look, I
need:
- What zener is D4? Can you read the tension between its legs?
- What tr is Q4? Is it really inverted on the board?
- Taking a look at schematic, what are the tensions on the points A
(should be +5), D (should be +5), 6-7m 6-8A (should be -5V), 6-9A
- Is there any documented mod for changing the internal power supply for
a +/- 5V one (I think there is also 12V)?
Thanks!
Alexandre