Element ELEFW40C won't turn on.

[budm]

Re: Element ELEFW40C won't turn on.

Put the meter probes on those two legs of that filter cap that shows 37VDC, then hit the power switch to see if it even attempt to go up higher that 37VDC or not.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

I did as you asked and it stays at 37.2VDC. My wife pushed the power button a few times, just to make sure. It didn't even move a little.

[budm]

Re: Element ELEFW40C won't turn on.

One thing is that I do not expect the 12V to be present all the time otherwise it will running 24/7. Some thing has to switch on.

[budm]

Re: Element ELEFW40C won't turn on.

BTW, you may as well check the DCV of the rest of the pins.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

BTW, you may as well check the DCV of the rest of the pins.

I'll double check and see if that 12VDC is on VIN when the TV is first plugged in (before it's turned "on"). I don't think I can check all the pins. They're too close together. My probe will short them out.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

Okay, the VIN has 12.10VDC, whether I push the on button or not. The outer other three pins all have 0VDC on them. I haven't tried checking the inner ones.

That one capacitor that has the 37VDC, should I try pulling that and checking it with my ESR meter? The top isn't swollen but for some reason, to me, it just doesn't look right. Maybe I'm just not used to looking at caps on their sides like that though.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

I found another picture of that chip. I believe it's the same picture as before, but this appears to be the complete picture, whereas the first one appeared to be cropped a little.

https://img-fotki.yandex.ru/get/1949..._2c4d30f7_orig

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

Budm, I'm an idiot. It's not an 8-pin chip, it's a 10-pin chip. So maybe the top chip, UB802, is our chip, not UB801. I looked at it under the lighted magnifying glass I have and counted the pins again. Sorry!

I wonder if the ISET pin can be used to turn it on and off?

On a Russian website, someone asked for the datasheet for that SN51DP. Someone else told them to compare it to this chip, because they're very similar: https://cdn.badcaps-static.com/pdfs/...92964173d4.pdf

That link is for an 8-pin, but it tells us what the various pins are, minus those two extra ones that my SN51DP has (the ISET and REF). I believe ISET is current set.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

Also, this SMD component that I think is an SMD capacitor seems to have really high resistance when I put probes on each end of it. It measures around 14 Mohm. Is that normal? The other ones in that area don't measure anywhere near that! I was thinking maybe it's a bad capacitor.

[dick_barton]

Re: Element ELEFW40C won't turn on.

Capacitors normally read Meg ohms to open circuit when tested with a multimeter. Best to check with capacitance meter.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

Capacitors normally read Meg ohms to open circuit when tested with a multimeter. Best to check with capacitance meter.

Thank you.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

The Hisense 40H3E seems to have the same board, from what I can tell (MS3393.PB851)
A Westinghouse DWM42F2G1 service manual or schematic might work as well. The audio connections are a bit different, but the rest of the board is the same....

Maybe we can find a schematic for one of those televisions and use it to help fix this one?

[budm]

Re: Element ELEFW40C won't turn on.

Also, this SMD component that I think is an SMD capacitor seems to have really high resistance when I put probes on each end of it. It measures around 14 Mohm. Is that normal? The other ones in that area don't measure anywhere near that! I was thinking maybe it's a bad capacitor.

That is MLCC, common failure mode is shorted or very low resistance, I doubt that it is bad. We are working without the diagram an without spec the spec sheet for the parts so it is not going to be easy, we know what the power supply sections are, the backlights LED power supply are, but we do not know where the command signals are.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

That is MLCC, common failure mode is shorted or very low resistance, I doubt that it is bad. We are working without the diagram an without spec the spec sheet for the parts so it is not going to be easy, we know what the power supply sections are, the backlights LED power supply are, but we do not know where the command signals are.

Do you have any suggestions on how I might find them command signals? I was thinking (which is never any good!). I can press the power button and I see the voltage drop on the pin for the power button. Can I try to trace that somehow? Maybe put the DMM in continuity mode and try tracing where that power pin goes to? Then, maybe try to follow the electricity or something? Maybe that'd give us a better idea what's going on.

Element got back to me but all they said was they suggest I call support and gave me an 800 number. I highly doubt support is going to send me a service manual. They'll just say I need to send the board in for repair. Do you think it's worth even calling them?

[budm]

Re: Element ELEFW40C won't turn on.

The command signals will be coming from the Micro controller, so you need to know which pins are assigned for the command output, and that output nay be buffered by a transistor and so on and on, without diagram you will then be reverse engineering the board to find out how it is configured.
How much is the replacement board?

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

I got my needle probes and went back to that LED Driver IC. I measured the pins. There's no change when it's "off" and "on". All of them show 0.000VDC, except for two pins.

Pin 1: 12.10VDC
Pin 9: 0.664VDC

According to that diagram, pin 1 is VIN (which I believe is correct) and pin 9 is OVP. I believe that's the Over Voltage Protection input pin for Boost mode.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

The command signals will be coming from the Micro controller, so you need to know which pins are assigned for the command output, and that output nay be buffered by a transistor and so on and on, without diagram you will then be reverse engineering the board to find out how it is configured.
How much is the replacement board?

I couldn't find a replacement board for this television, but I didn't look too hard, I just checked shop jimmy. I'll look at other sites now and see how much one is.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

60$ OBO, free shipping, on e-bay, for a used one. That's the cheapest one I could find. They have other ones at around 135$.

[Spork Schivago]

Re: Element ELEFW40C won't turn on.

I measured the voltages on the eeprom or whatever you want to call it. The 8-pin 25Q16BSIG ( http://www.datasheet4u.com/pdf/25Q16...65306#download )

I was hoping maybe it really is bad. I saw a lot of pins that had 3.32VDC on them.

pin 1: 0.000VDC
pin 2: 3.320VDC
pin 3: 3.320VDC
pin 4: 0.000VDC
pin 5: 0.000VDC
pin 6: 0.000VDC
pin 7: 3.321VDC
pin 8: 3.321VDC

After looking at the datasheet though, I think the pins that have voltage are supposed to have voltage. I didn't see anything on the output channel, but I probably wouldn't unless I was measuring it while someone pushed the on button.

[vinceroger69]

Re: Element ELEFW40C won't turn on.

60$ isnt too bad for a combined board theres a lot on it i guess its down to what the customer want too pay for a repair.