Hi:

I have a Viewsonic G810 CRT monitor on the bench with a weird horizontal
problem.
I'll start at the beginning.
The picture started to wiggle horizontally. Sparks could be heard close
to the HV section. Eventually there was a bright vertical line then the
screen went dark.

Cause: A 4-pin connector was completely fried. It connects two blue and two
grey wires, which are slung in an 8 around the neck of the CRT and the
yoke.
Also the horizontal transistor 2SC5411 was fried.

The flyback, which was the first suspect, is OK however.

Now to the weird problem:

When switched on, the picture shows briefly on the screen. It is a bit
murky.
It also is masked on the left from top to bottom by a curved black zone
about an inch from the edge.
On the right it is masked with a curved black zone, but this one is
running from the right screen edge into the middle like a tsunami wave
covering real estate. Then something switches off the cathode ray. HV is
still present.
Switching the monitor off and on repeats the phenomenon.

Disconnecting the connector with the blue and grey wires reduces the
picture to a bright vertical line.

Mind: the picture is not squeezed in the horizontal direction - geometry
is OK but the dark zones mask the picture.

I never before saw thelike and have no idea what may be wrong.
I thought I connected back everything correctly but I may be wrong.
Is somebody out there with a hint for me - short of trashing the old
monitor and to get myself a new LCD one.

Kind regards
Eike Lantzsch

Replace the flyback transformer part # Tlfa01365, & resolder the
horizontal drive, & power supply section. Hope this helps.

Replace the flyback transformer, part # Tlfa01365, & resolder the
horizontal drive, & power supply circuits. This should fix it up.

Dani wrote:
Replace the flyback transformer part # Tlfa01365, & resolder the
horizontal drive, & power supply section. Hope this helps.

Thank you so much for your suggestion. I'm still not sure if the flyback
is bad. Lets see if I can get a new one locally. Probably not a
PANASONIC - might be second source junk too. I'm in Paraguay.
If so I'll trash the monitor - not worth it.
The problem is not with the horizontal deflection but the video signal
is partly blanked (masked) out. The unit had no problems with the video signal
when the picture started to wobble horizontally. So I still guess that I
made a more or less dumb mistake when replacing the fried plug. But I
marked the four wires and the fault is the same either way they are
connected - beats me.
Good advice to resolder the horizontal stage and the power supply. I
already had to resolder the complete video board on the neck of the CRT
at an earlier occasion when sporadically colors were missing. The whole
PCB seems to be soldered very badly. One can't even see the difference
between a cold solder joint and a good one. What kind of solder did they
use? Not lead-less I think because the unit is so old.
Man I love the old Tektronics which came with a roll of silver solder
and the warning not to use anything else for repairs.

Kind regards, Eike