TV problem....advice needed

I have a 10 year old? 13 inch Magnavox that periodically has a
video problem.

The screen turns entirely off white with a series of thin brighter
white lines running slightly diagonal. There are perhaps 20 of
these white lines across the off white screen. The sound works
fine.

I can correct the problem by flipping a switch from cable to normal.
Then I just switch it back to cable and it works fine for hours. I
have noticed one other problem that may or may not be of help.
The screen is slightly enlarged upon startup and cuts off about an
inch of the upper part of the screen. Maybe the bottom too?

Any suggestion on where to start?

 

[Jerry G.]

The problem may be in the HV multiplier, which is usually part of the
flyback assy.

Sometimes a defective CRT can also cause this.

When turning the set off and on, or causing a transient with the cable
switch, the fault gets temporarily subdued for some reason.

For best accurate analysis, you should have a service centre properly check
the set. They will take voltage readings, and verify the HV multiplier and
the CRT, for you.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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<tnom@mucks.net> wrote in message
news:c0ij10husemalqk1hmhlsb0190jc73qgff@4ax.com...
I have a 10 year old? 13 inch Magnavox that periodically has a
video problem.

The screen turns entirely off white with a series of thin brighter
white lines running slightly diagonal. There are perhaps 20 of
these white lines across the off white screen. The sound works
fine.

I can correct the problem by flipping a switch from cable to normal.
Then I just switch it back to cable and it works fine for hours. I
have noticed one other problem that may or may not be of help.
The screen is slightly enlarged upon startup and cuts off about an
inch of the upper part of the screen. Maybe the bottom too?

Any suggestion on where to start?

 

[James Sweet]

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:bvctd4$bif$1@news.eusc.inter.net...

The problem may be in the HV multiplier, which is usually part of the
flyback assy.

Sometimes a defective CRT can also cause this.

When turning the set off and on, or causing a transient with the cable
switch, the fault gets temporarily subdued for some reason.

For best accurate analysis, you should have a service centre properly
check
the set. They will take voltage readings, and verify the HV multiplier
and
the CRT, for you.

--

Probably not worth doing that for a 13" set. I would start by poking around
looking for cracked solder joints around the flyback and on the neck board,
as well as bad capacitors in the power supply. Some freeze spray could track
those down if an ESR meter isn't available. Let the set warm up so the
vertical expands, then squirt caps until it contracts and replace that one.