Quote:
Originally Posted by kf4rca
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I'll assume that the vertical lines shown in your first pic were reflections. If you have vertical stripes on the screen, the rest of this won't apply:
I've changed a hundred of the AS15 chips on TCON boards before (as shown in that Samsung youtube linked video), but I never saw one become intermittent like that. But one thing I've learned in the 50 years I've been in consumer electronics is that I haven't seen it all, nor will I.
Usually, the AS15 chip failure presents one of three ways: the picture is washed out and faded, or the picture is "overexposed" with too much contrast (severe gamma error), or the picture starts out normally and degrades quickly over a minute or so. The last symptom being restored with cold spray.
I have never seen one become intermittent where it will be crappy and then snap back to normal.
If yours seems to turn on reliably but cut out after a few minutes, you can try freezing the AS15 chip on the TCON to keep the picture running. It it does, replace the TCON or the AS15 chip if you're comfortable doing SMD work.
Also, the AS15 chip runs just slightly warm under normal conditions. You can test this by putting the back of your finger between the first and second knuckle when it's running (all TCON voltages are low voltage - quite safe) and see if it gets hot. If you feel a sharp rise in temp on the back of your finger, the chip is bad.
John