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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What are Q601 & Q602? D601 might be a STTH10LCD06FP, I don't have this schematic
Check all the components in the gate drive of the mosfets there are two resistors from source to ground, are they both ok?Last edited by R_J; 09-01-2024, 06:54 PM. -
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.Attached FilesComment
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A few lg power supplies used a IDT02S60C but I might go with a IDT10S60C
If you were the first person to open the tv the top of the diode will still be there somewhereLast edited by R_J; 09-02-2024, 11:56 AM.Comment
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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.Attached FilesComment
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If you can't find it, Infineon replacement is IDH04G65C5IDH04G65C5XKSA2 Last edited by R_J; 09-02-2024, 04:48 PM.Comment
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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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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
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I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy... -
I was working on this CNC machine today found no keyboard functioning no control relay powering on
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Found shorted diodes on main controller relays there are 3 of them that... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
I saw this switching power supply on eBay and wanted to see if could be modified to run 14.5 volts before the blocking diode was add and this switching power supply seems to have no issues doing this
I did recap the switching power supply except the the main filtering capacitors and I managed to break the selector switch for the voltage setting but just jumped it
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