Entertainment Center: TVs, Stereos, VCRs and DVDs - Magnavox 55-inch screen darkened, enlarged

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woodhick
11-15-02, 10:07 PM
I have a 55-inch Magnavox big screen that was built in 1989. The TV came with the home I purchased, so I don't know its history.

Earlier today, it was working fine. Came home a few hours later, turned it on and the picture is suddenly dark and enlarged. I can make out images, but it is much too dark for enjoyable viewing and the images are bigger than the screen. The on-screen clock and channel display is only partially visible because it extends beyond the viewable area.

I turned up the brightness, tried to adjust convergence but to no avail.

Any thoughts on what the problem might be? There was no previous indication in the five months I've owned it that the picture was going bad.

Thanks much.

FREDDYG_001
11-16-02, 10:35 PM
Sounds like the power supply module is failing. Common problem. Part number is on a white sticker on the module. Post back with this information.


Fred:)
woodhick
11-17-02, 12:26 PM
Thanks for responding, Fred. The TV has now gone entirely black, but there's still sound.

I took the back off and have discovered this, which I hope will be helpful:

TV model #RK8560 AK02

AC panel PTV400
A10346-A001
89453 M4T3 624


Convergence Power Board
A10365-B002
89453 M4T3 582


PTV H.V. Power Supply
CTN6220
EIA232D

Any input would be helpful.

Thanks.

FREDDYG_001
11-17-02, 02:08 PM
Like I was saying before the power supply is the most common failure with that chassis. Look for this number on the module #704978-3 or a number similar. Its probably been changed before. If you remove the module and check the reg. and h-out transistors they'll probably be shorted. I'll check for and tech tips on this model.



Fred:)
woodhick
11-18-02, 09:12 AM
I have contacted a local repair shop and, without looking at the TV, he estimates the horizontal power and the power supply will have to be replaced (he said one typically goes bad, and the other shortly after, so they just estimate both anymore) . . .

At that, he estimates about $400 for the parts, and labor may be more.

Does that sound about right?

Help!

Thanks,


Matt
XperT PC
11-18-02, 05:57 PM
My guess is just bad caps on the power supply board, being 13 years old they getting high resistance.