Maker Pro
Maker Pro

Viewsonic G790 horizontal collapse

J

James Sweet

Jan 1, 1970
0
Just got a Viewsonic G790 with the horizontal squished into a band about 2"
wide from top to bottom. Obviously the H-deflection transistor is ok,
anybody seen this before I dig in?
 
R

Rono

Jan 1, 1970
0
From what Iv'e seen of your posts, you know what
your at, but look for bad connections at the deflection
yoke, capacitors in the picushion circuitry, or at the
flyback! Rono.
 
J

Jerry G.

Jan 1, 1970
0
If I recall correctly, many of these monitors use a separate HV and H
deflection output stage. Check if this is correct for this model of monitor.
The only way to find the faulty components would be to trace the signal
path, and measure the signal levels back from the deflection yoke. Or, find
the scan signal source and scope it through. I realize that this is much
easier said than done.

--

Jerry G.
======


Just got a Viewsonic G790 with the horizontal squished into a band about 2"
wide from top to bottom. Obviously the H-deflection transistor is ok,
anybody seen this before I dig in?
 
J

James Sweet

Jan 1, 1970
0
Rono said:
From what Iv'e seen of your posts, you know what
your at, but look for bad connections at the deflection
yoke, capacitors in the picushion circuitry, or at the
flyback! Rono.

I'm looking at the board right now, go figure, it's one of those that is
arranged in a way that makes it nearly impossible to do any sort of
measuring while powered up. Soldering looks pretty good, visual of the caps
is ok, I'll keep poking around.
 
J

James Sweet

Jan 1, 1970
0
Jerry G. said:
If I recall correctly, many of these monitors use a separate HV and H
deflection output stage. Check if this is correct for this model of monitor.
The only way to find the faulty components would be to trace the signal
path, and measure the signal levels back from the deflection yoke. Or, find
the scan signal source and scope it through. I realize that this is much
easier said than done.

Yes this does indeed use separate HV and deflection (as I think all
reasonably modern multisync monitors do), HV is working just fine, as I
mentioned in another post, any kind of live measurement is much easier said
than done, all the cables are too short to access most of the bottom of the
board with them plugged in.
 
Top