RE: GO7 with low B+ voltage

Hey, it's a one man thread!

Anyway, I got the replacement parts, and found C107 on the CRT board had
leaked and was missing a leg. "Ah ha," I say to myself. "I can't believe
this thing worked at all. Man, monitor repair is easy. Just look for bad
components and replace. I'll have this baby working great in no time."

So I solder everything, put the chassis back in and power it up. HV sings,
no smoke, nothing pops. Now to see my perfect picture. It's rolling on
both axis's still. So I fiddle with the V. Hold and H. Freq. Same thing as
before, it won't stabilize. I measure the B+. 105 VDC. Up 5 volts from
before, but still not good enough. Try to adjust it, and get nothing. I
can't adjust it up or down by any amount. Voltage on the other side of R1
is 165 VDC.

My original question about the X04/NTE94 swap still stands.
Randy's flowchart says to swap C904 if Voltage on both side if R1 is low, so
I think I'm OK there.
As soon as I get the low B+ sorted out, I move on to whatever else is wrong,
if anything.

What could be causing the low B+?

-----Original Message-----
From: owner-rasterlist@synthcom.com
[mailto:owner-rasterlist@synthcom.com]On Behalf Of Sean McLachlan
Sent: Friday, June 20, 2003 12:49 AM
To: rasterlist@synthcom.com
Subject: RE: RASTER: GO7 with low B+ voltage

Well, I decided if I was going to fix this, I would have to pull out the
chassis and get a better look at it :). Just for posterity, here is what I
found:

broken resistor leg on R703
R414 shorted open and badly burnt
R415 corroded and badly burnt
FR401 corroded and burnt
2 legs of IC 501 with puckered solder joints

So I guess I should have pulled the chassis BEFORE posting, huh?
(Advice to other new guys: Pull chassis BEFORE posting)

On the plus side, it had already had a cap kit done on it.
I don't have all the parts I need. I'll post if this solves the problem.

Sean McLachlan
MIS Manager
LithoFlexo grafics inc.
801.484.8503

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Received on Sat Jun 21 23:32:41 2003