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#1
08-04-2011, 06:46 PM
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if I break the circuit at L001 the 12v source and the 5.2v at 4a come up, reconnect L001 and the stand by 12v drops to 7v, the 100 ohm resistor R005 gets hot. So it looks like a problem after L001. I checked the to eletrolytic caps, both fine. the .1 looks like some kind of surface mount, my guess is that is not the problme. The 4b goes directly to the main mother board IC, so I am thinking something bad happened there. Dumb thing must have 80pins on each side, but it is thru holes so I guess if I got real board I could attempt to remove, that is assuming its the problem AND I could find a replacement. D011 was also shorted. I replaced it with some generic diode. before doing that the 12v was 5v (replacing it brought it up to 7v, disconnecting 4b brought the 12v source back to 12v).
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#4
08-07-2011, 09:57 PM
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Yep, the micro is bad. Jump the relay and see if the HV comes up. It won't do much else, since the micro IC must be working in order for the tuner and the control circuits to operate. If the HV does not come up, you likely have other problems that could lead to a bad jungle IC, defective horizontal driver circuit components, defective power supply components, bad parts in the HOT area, or any combination of the above. Horizontal drive comes out of the jungle IC, to the horizontal driver stage, to the horizontal output transistor, and then to the flyback. A loss of horizontal drive anywhere in this chain means no HV.
If you get HV, you can feel a little better about changing the micro IC. However, I wouldn't be surprised if the tuner is toast and there could still be other damage to the set. Lightning is funny stuff that can do as little as blow the fuse and do as much a cook (literally) the chassis. I've had lightning damaged sets where it would be one part after another. Back in the day, it was usually worth the effort because a 27" TV was actually worth something. Now, I probably wouldn't go any further than the power supply before I bailed on it.
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#5
08-08-2011, 07:33 AM
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My new concern is if the EPROM requres any preprograming not covered in the SAMs. I am assuming if its a panssonic part number then it should have any basic program already installed? one more thing I assume I have to be careful of ESD damage when I get a new IC. Not checked out on that, but seem to recal folks where ground straps and have certing types of floor mats to stand on when handling them.
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