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Discussion Starter #1
After turning on my 43UWX10B for about a minute, the power light on the front started blinking about 4 times a second in time with a squealing noise from the rear. The picture and sound disappeared.

I trying disconnecting the power overnight, but the problem persists. Two small green lights on the main board blink in time with the red power light on the front and the noise.

I totally disconnected the convergence board, and the blinking and the noise stopped, but the screen lighted up for only a few seconds.
In times past, I have noticed some convergence problems that lasted for only a short time.

Thank you for any advice on further action.
 

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Discussion Starter #3
Thanks for the input. I have ordered the Hitachi kit for replacement of the ICs.

I need to update my soldering equipment. I read in the thread that you recommend a 40-45 watt gun, but do you have a specific recommendation for one, or a particular type, at the local Radio Shack? Or some to avoid?

Thanks.
 

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I like the Hakko that I have linked, but that may be more than many would like to spend.
 

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Discussion Starter #5
Thanks lcaillo.
I have received the new ICs, the old ones are out, and new ones mounted and ready for soldering.

All the resistors look OK, but I guess there is a chance that something else is the cause of my distress. I will find out soon. Do you make housecalls in this area?
 

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It is rare but I do get over there sometimes. You are near Palatka aren't you?

The squeal is not a typical symptom. Usually when a chip goes, it either continues to run or blows a fuse and the set goes into shutdown. Hard to say what it might be without doing some tests.
 

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Discussion Starter #7 (Edited)
lcaillo,
I soldered the ICs, installed them, inspected the board carefully, and fired up.
Everything appears to be working perfectly. The convergence is right on, without any adjustment. (I DID go to church this morning.)

There was (what appeared to be) heat sink compound that leaked over the top of the board in places. Could that have been part of the reason for failure. Q-tipped as much off as I could.

Another data point for the troubleshooting chart.

Thanks to you and all the contributors on this board.
 

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Are you sure it was heat sink compound? If it was only around the heat sinks it likely is, but if it was elsewhere you need to be sure that it was not CRT coolant.

Heat sink compound has silicone in it and that will not hurt anything. It is not conductive and generally does not become so. Coolant is a big problem.
 

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Discussion Starter #9
Yes, I am pretty sure it came from under the old ICs. There was a lot of this stuff under and around them.
It looks like it flowed under the heat sinks, and it was just in that area. Whoever installed the old ICs was very generous with it.
 

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That could be why they failed. Lots of people put too much heat sink compound, and it acts like an insulator. If it is the type that separates, when the silicone runs out and you have a thick chunk of the solid behind the chip, they really do not transfer the heat well at all.

Always use a thin layer and press and slide the chip on the heat sink until the metal meets metal. Heat sink compound should only fill in the gaps.
 
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