Sanyo DP46841-00 No power, no lights, no picture

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

There's voltage regulators on the back of the analog main. On mine, one of them was getting real hot and I wasn't able to get a voltage reading from it. But then I removed a jumper, disconnecting the regulator's output from the digital main, and was then able to get a reading of 3.3v. As I'd said earlier, the CPU was shorted between 3.3v, 1.5v, and ground. The service manual for this TV is very good. I would see if any of those regulators are getting hot.

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

If you need something specific let me know.

This is more a learning experience at this point more than anything.

[zacheriaj]

Re: Sanyo DP46841-00 No power, no lights, no picture

There's voltage regulators on the back of the analog main. On mine, one of them was getting real hot and I wasn't able to get a voltage reading from it. But then I removed a jumper, disconnecting the regulator's output from the digital main, and was then able to get a reading of 3.3v. As I'd said earlier, the CPU was shorted between 3.3v, 1.5v, and ground. The service manual for this TV is very good. I would see if any of those regulators are getting hot.

Would you like to direct him towards testing that LDO. Its likely a common issue.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

Yup. Take some pics of the back of the analog main. Then I'll tell you what to check.

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

Yup. Take some pics of the back of the analog main. Then I'll tell you what to check.

Going to Necro my own post.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

I just pulled my old board from my PCB graveyard. I need an LV4906 audio amp for a Sanyo DP50741 and it's my lucky day, it's got one.

[ryanfan03]

Re: Sanyo DP46841-00 No power, no lights, no picture

I have a similar problem with my hitachi. I bridged the ps-on to 5v and didn't get any 12 or 24v. What should I test on the main to see if it gets any voltage. I can create a new thread if need be.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

You're better off creating a new thread since it's a different TV. Post the model number in the title and take some good pics of both sides of the boards. That will speed up the process of getting help.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

Success, and it was completely free! I even found a B0ACCK000005 diode on the board to piggyback onto the L008 inductor, as suggested in the service manual, to protect the IC. Did I mention the repair was FREE? lol

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

Success, and it was completely free! I even found a B0ACCK000005 diode on the board to piggyback onto the L008 inductor, as suggested in the service manual, to protect the IC. Did I mention the repair was FREE? lol

Any thoughts on how to test this to verify it is the problem with the tv?

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

What you quoted was actually regarding a DP50741, in which, I used the audio IC from my scrap DP46841 board. Was that what you meant? If you were referring to the DP46841 issue, I would see if the 3.3v stby and/or 1.1v stby are shorted to each other and/or ground.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

Oh, I didn't realize you were the OP on this thread. It appears your version is Z5WF. I'll see if I can find the SM.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

Here you go.

Edit: I Just read through this and realized I already found you the SM. You'll have to read through it and find where to test the 3.3v stby, and 1.1v stby.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

On the back of the analog board, find IC1600. That's the source of the 3.3v stby. You should have 5v on pin 3, and the output will be 3.3v on pins 2 and 4 (4 is the tab).

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

Why didn't you guys tell me I was photographing the wrong board. Not sure why I thought I needed to take pics of the digital main.

So if IC1600 is not putting out the correct voltage what does that mean.

I assume I need to have everything put together in order to test this IC?

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

If the power supply is providing 5V then IC1600 should take it in on pin 3 and produce 3.3 out of 2 and 4 which then feeds the digital main board telling it that the power cable is plugged in and the power supply is ready. Correct?

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

What should I use for a ground? Sorry I am a newb at this.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

You didn't photograph the wrong board. On my board, the short was on the digital main, but the 3.3v stby is produced on the analog board. Yes, you will need it all together to do this. You will be working on the bottom, so you will have to flip the boards over. I usually put a piece of cardboard under them so nothing shorts out against the backlight assembly. As for a ground, just use any of the pads where the screws went through the board.

[lookimback]

Re: Sanyo DP46841-00 No power, no lights, no picture

Take a couple pics of the analog board too. Front and back.

[kage]

Re: Sanyo DP46841-00 No power, no lights, no picture

ok so IC 1600 reads 2.08, 3.3, 5, 3.3 volts clockwise from pin 1.