Sanyo DP42849 - No Power At All

[tom66]

Re: Sanyo DP42849 - No Power At All

Yes, you want the TV to do that power light up briefly.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Yeah I just realised it doesn't even bother trying to turn on unless the other boards are plugged in.

0 on voltage test when power button is pressed.
1 on resistance test when TV is unplugged.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

On the resistance test, I do get a reading when it's on 20M - 1.45

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

BTW - I retried that hair dryer on caps thing yesterday too, since I put the new IC in, but it didn't work.

[tom66]

Re: Sanyo DP42849 - No Power At All

You using 20VDC scale? 0.00V?
No short, so it must be in ckt that feeds that part.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Yes - for 20DCV, I got 0.00.

But I did get something on resistance test when moving up to 20M.

[tom66]

Re: Sanyo DP42849 - No Power At All

Now I need you to test the macro mode of your camera. Best pic you can get of area around J38 (bottom, green side)? Need to see small parts and traces.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

I posted some pics in #214. They should zoom in when you click the magnifying glass. Do you need closer than that?

[tom66]

Re: Sanyo DP42849 - No Power At All

Didn't see those. I've highlighted some points to ohm out. Please test between the RED and each BLUE points in 2000 ohms. If I have the circuit right, they'll all show near zero.

Also, the part# of IC301 would help too

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

I pulled the board out to test.

Point 1 - 0.01
Point 2 - "1"
Point 3 - "1"

DDA002B
PAA0909G

[tom66]

Re: Sanyo DP42849 - No Power At All

OK, let's try again. Test as before.

DDA002B is available, but appears to be a proprietary Delta part (most likely specifically marked rather than dedicated design, but it makes it hard to find a datasheet for it.)

[tw2005]

Re: Sanyo DP42849 - No Power At All

I found a C variant as an ON SEMI component, 19pin. Do you think this pinout helps at all?

http://pinout-circuits-images.dz863.com/30/DDA002C.jpg

[tw2005]

Re: Sanyo DP42849 - No Power At All

http://www.dz863.com/circuits-2-8160...ation-Circuit/

[tw2005]

Re: Sanyo DP42849 - No Power At All

http://www.datasheetlib.com/datashee...html#datasheet

[tom66]

Re: Sanyo DP42849 - No Power At All

Nice one... Looks like a good match

[tw2005]

Re: Sanyo DP42849 - No Power At All

you're welcome

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

You guys are really great at this, and I appreciate all of your help. I think if I were better at this, we would be farther than we are :/

I will retest in a bit, but I have a question. Someone on my local Craigslist just posted my exact same model and chassis for $35. It stays turned on, but no picture.

I'm thinking of offering him $20 for it and trying the power board in mine. I've been eying boards, and my chassis is out-of-stock everywhere, and if it ain't, it's $100 plus. There's one on eBay for $60, but what a hassle if it doesn't work. At least this way, I can see it working and only be out $20 if it doesn't fix mine.

What do you think?

Here's a thread on the same TV, same problem.

[vinceroger69]

Re: Sanyo DP42849 - No Power At All

i would try to get the one of craigs list if it was me before it goes!

[budm]

Re: Sanyo DP42849 - No Power At All

Parts are worth more than $35, it is a good deal even @$35.

[tom66]

Re: Sanyo DP42849 - No Power At All

No picture, there is a chance that big inverter transformer is bad, (if no backlight) but you can swap them over, it's just a lot of work.