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Originally Posted by kf4rca
Thanks. Sorry for being late getting back to you. The AS15 chip is on the VOCTL board rather than the TCON board.
I've done some SMT work but maybe not as fine pitch as this is.
There seems to be several versions of the chip out there-all with different suffixes. What is the difference and are they interchangeable?
They have an AS15 chip in stock at the local AudioLab for $6. They used to do video work too but now only do audio repairs.
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Electrically they're the same, but there are two different case versions: one is all plastic and the other has a metal bottom. Otherwise they have the same exact dimensions and pin pitch.
Because the metal bottom is soldered to the PC, the metal bottom chip has to be removed with hot air. The all plastic version can be removed with hot air or a low temp alloy like ChipKwik from the top.
I generally stock the metal bottom one as it will sub either, but some PCs have some feed through holes below the chip so the metal bottom one might short to the feed throughs on the board, but that's rare.
If you go to Alibaba and enter your exact part number, you should be able to see which one you have by the picture. Check several vendors in case one is using a stock photo.
If it's all plastic, it's far easier to change than the one with the metal bottom.
I've never done it, but several techs have told me they used the plastic chip in place of the metal bottom version. They put a dab of heat sink compound between the chip and the board and they say they will work. It's not a high power chip so I would think they'd be fine.
Now, I was buying these in lots of 20 for a few years from Alibaba, but occasionally got bad batches. I then used TSL1014 from Digikey for the plastic versions and they worked great, no failures. These have plastic bottoms. I've never gotten bad semis from DigiKey ever, so that's no surprise that I never had a new one fail. I used my supply of 1014s up and have a couple of metal bottom AS15s left from an earlier China order, and these seem good, but I think it's been a year since I last used one.
Since these TVs are older, the repairs on that vintage is drying up. I'll reorder the TSL1014s from DigiKey if I run out and get another in to repair.
EDIT: Now that I think about it, I recall some chatter about a suffix version of the AS15 that was not compatible, the E2 IIRC. So if you have a AS15F, or G, or any single letter suffix, they will all interchange and you will be fine - avoid any version with a number in the suffix. I don't recall ever seeing an E2 but if you get an E2 sub, it won't work.
John