This is on the power supply/backlight inverter board EAY57681601 for LG 47LH40-UA television. The supply failed when commanded from standby to run, taking out the main fuse. I'm trying to identify diode D601 in the inverter section where the package was blown apart and the markings are gone. Q601 and Q602 will need to be replaced also. If anyone can point me to a schematic that would be most helpful. Also would like to hear if anyone has repaired this type of failure before.
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LG EAY57681601 power supply diode
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Thanks for the info! Q601 and 602 are TK12J60U, a 12A 600V MOSFET. They are run in parallel, but one shows shorted gate to source, the other about 2K. Both read about 2 ohms drain to source, so at least one is shorted. The gate to source resistors are 10K and look ok with a microscope. On your question, the source terminals are commoned but there are two 0.2 ohm resistors in parallel from there to ground that are intact. I had to lift one end to check them. Gate circuits look OK, plausible junction drops in both directions on the gate drive/clamp circuits. Resistors measure as marked. Bridge rectifier OK.
On the fast recovery diode suggestion, that part looks plausible for the position, except that the original was in a standard TO220 with a silpad insulating it, not an insulated package. The leadframe had the center lead joined per the attached photo. Interesting that the board was laid out to have another diode in parallel with this one, like one isn't enough for some cases.
This TV does not have a lot of hours on it in spite of being old. I'm wondering if a line transient set this up for failure.
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I can't believe I found it! Of course I had looked before everywhere inside the TV but no luck. It was actually lying under where the TV was mounted. Since it was wall mounted, there was a hole in the case where the base mount used to be. Must have ricocheted around until it found the hole.
Photo is attached - you pretty much nailed the part number: D02S60C. Thanks again.
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Success! Replaced the failed parts and it is back in service. It's run for an hour so I'm going to declare victory. Here are the part substitutions in case anyone needs to fix the same problem.
Failed Replacement
Diode D02S60C IDH04G65C5XKSA2
MOSFET TK12J60U STW18N60DM2
8 Amp slo blow fuse Littelfuse 0477008.MXEP
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