Sanyo DP42849 - No Power At All

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Actually, D902 reads good without any IC 901 there.

[tom66]

Re: Sanyo DP42849 - No Power At All

It should do. I think that chip was the only cause of the fault. You can try testing it now.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Okay, with the new chip in, the D902 diode reads a little lower at 488.

491.

[tom66]

Re: Sanyo DP42849 - No Power At All

Absolutely fine.
Now for the smoke test :p.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Okay. Here I go.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All



Pressing power button gave me a green light that stays on for about 5 seconds, then turns off. I can do this 3 times before it locks and I no longer get any response.

Just like this - http://www.youtube.com/watch?v=KSYCn93pz6k

[tom66]

Re: Sanyo DP42849 - No Power At All

Well, you got somewhere. But you probably have additional fault, if there is damage due to surge, for example. The lit up LED going out reminds me of the flash memory problem, or Norcal's voltage check.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Well, the new chip and diode still test good, so that's something.

Should I check the same chip this fellow does in his video?

[tom66]

Re: Sanyo DP42849 - No Power At All

Yes.... I would do that.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Actually, I haven't got the same board as he does. Not sure what to do next.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Also, I don't hear any click when I press power.

[vinceroger69]

Re: Sanyo DP42849 - No Power At All

does the voltage on the main capacitor change now from when is standby and powered on.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Well I tried measuring voltages on the pins again, and I'm not getting anything on any of them. Not sure if I'm doing it right - the tip of the lead can barely fit through that plastic connector, and it isn't going very deep.

Both with TV plugged in and power button pressed once.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

When I check that large diode D951 I get 212 one way and 1042 the other.

[tom66]

Re: Sanyo DP42849 - No Power At All

You have standby LED, so for now, that part of PSU is not of concern.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Well, I have green power light.

What should I do next?

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Tested main cap. 165 when TV is plugged in. It does not change when I press power button.

Same TV, similar issue here. There's no standby light on this set apparently.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Tried to turn it on with main board disconnected. No green power light or anything.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Well, I was looking through the service manual again (for a different chassis anyway), and at the beginning of page 5 it explains how the Power Failure Circuit works. What it describes is exactly what my TV is doing: "CPU will turn the unit off in 1.5 seconds" and ". . . set will enter standby mode".

It gives the same instructions that Norcal followed in his video, but since this is for a different power supply, I'm not sure it applies.

I took a closer look at my board, and I do see an "800" next to the IC in question, but I can't tell if there's an "IC" in front of it since there are holes over the text.

I'm having a little trouble understanding exactly how to test the pins 48 and 23, or even if those are the pins I should be testing on my particular model. Can anyone please assist me with this?

[tom66]

Re: Sanyo DP42849 - No Power At All

Can you post a picture of this IC? Can try and highlight the pins - it is tricky though but if they are on the edge, it is easier.