Sanyo DP52449. Won't turn on & main board problem.

[johnboy1313]

I picked this up yesterday. It won't power on. I opened it up and the main board has 14 bulging caps on it. The seller claimed that it occasionally worked and that once it was on, it worked fine. Who knows.

The problem is that everything I read says the DP52449 should have the N7KE main board. It does have the N7KE PC board. The main board in this set is an N7AE, which according to everything I read shows it to be for a 42" Sanyo.

The set has obviously been opened up. Some inside screws are missing and some are loose. For what I paid for it, this doesn't bother me as much as it might bother others, considering it has a good screen. The guy I bought it from told me he bought it off of another guy in working condition but that it didn't work very long after he got it. Again, who knows.

I guess anything is possible. I'm wonder if any of you know if this board would have come in this set from the factory.

Also, if I replace the bad caps and power it up with this board, is there a chance I could screw up something else?

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Back to the top.

[tw2005]

Re: Sanyo DP52449. Won't turn on & main board problem.

With the reference NZAE, where abouts on the main board are you getting that from? the shielding and PCB print has NZAE but on the actual tuner module there's a long white sticker and on that you may find NZKE MAIN, etc.? That's what I'm seeing inthe Shopjimmy shots.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

I'm getting N7AE from the print on the PCB itself. The only sticker that I see on the main board has a 10 digit or longer number and a bar code on it.

Edit: face palm! The shopjimmy picture of the N7KE looks exactly like mine. Looks like I got ahead of myself. Stay tuned.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

I didn't read the note about the sticker being on the tuner. I was going by the PCB number, not the finished board number on the sticker. It wasn't until I looked at the large picture on shopjimmy that I saw it. My board is an N7KE board afterall. I just ordered all the caps from Digi-Key and will report back once it's been re-capped. Thanks for the heads up tw2005.

[tw2005]

Re: Sanyo DP52449. Won't turn on & main board problem.

I think it's even funnier my "7" is looking like "Z" this morning, glad you made sense of it

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Got the caps swapped out. No luck, the TV still won't turn on with the main connected. I forced the PSU on to verify that it and the backlights were functioning correctly. I'm going to send it to Coppell and see what they can do with it.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Picked up a used main this week via eBay for less than what it would have cost to send the original to Coppell. With the new board in, the set will power on and off via the remote, the backlights come on, but there is no picture. I was home on lunch break so I have yet to confirm if there is sound with a source connected. Right now, I suspect the PC board or the T-Con to be bad as well. At the connector on the main that runs to the PC board I see.

Pin 1 = 12V
Pin 2 = 12V
Pin 3 = 0V Possibly GND?
Pin 4 = 0V Possibly GND?
Pin 5 = 0V Possibly GND?
Pin 6 = 3.3V
Pin 7 = 5V
Pin 8 = 5V

It seems like the main is outputting what it should. I'm going to look for the service manual and see what it has to say.

My next step is to connect a source and see if I can get sound. If I don't, I will suspect this main board. If I do, how do I test the PC board or the T-Con? I suppose I'll need to get the scope.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Tom, any chance you could find the service manual for this thing? I'm not finding it anywhere.

[tom66]

Re: Sanyo DP52449. Won't turn on & main board problem.

I'll ask a friend if he can provide one.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

I connected a source and got sound. Fairly sure I'm looking at a faulty PC board or T-Con now, maybe even the panel. I guess I'll need the scope to know for sure, eh? This one has dual LDVS from the PC board to the T-con. What's the process for scoping either?

[tom66]

Re: Sanyo DP52449. Won't turn on & main board problem.

Backlight? No backlight? BLON good? BLON bad? 24V good? 24V bad? 12V to T-con?

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Backlights are on and responsive to the remote and power button. No 24V, this PSU has an integrated inverter. 12V from main to PC board is there. I probed every one of the wires on the row closest to me, I couldn't get to all of them on the back row. I saw no more than 1.4V at any of the wires from the PC board to the T-Con. I suspect I may have found my problem.

[tom66]

Re: Sanyo DP52449. Won't turn on & main board problem.

If T-con gets only 1.4V then check the power FET for switching it on and off -- if you need more help can we get a picture under the LVDS connectors. I have asked my friend and he should be able to get the manual but it will only be after the weekend.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Looks like I might be in trouble with this one. I was looking at pictures of the PC board on ShopJimmy.com and noticed a connector that isn't used on my set. I then remembered a connector on the main board that wasn't used and went to google images. Looks like there's supposed to be a cable that runs between the two boards and I don't have it. I hope I can find it.

Looks like I got bit by the previously-worked-on-tv bug.

[tom66]

Re: Sanyo DP52449. Won't turn on & main board problem.

That board it connects to is the 120Hz motion board. Without it, TV should still work, just no picture.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

That's where I'm at now. TV turns on and off with the remote and side controls. I have sound with a source connected. The backlights come on. No picture. Have you heard back from your friend about the service manual?

[tom66]

Re: Sanyo DP52449. Won't turn on & main board problem.

Not yet. Will have to see. He is in USA, but can only get them from his workplace.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Ahh, thanks. I've contacted several sellers on eBay that have a board or boards listed for this model. I'm hoping that I can get one that way.

[johnboy1313]

Re: Sanyo DP52449. Won't turn on & main board problem.

Tom, I just got off the phone with Sanyo USA. They have what they call the LVDS cable, part number 1AA4W30B60200, for ~$14.00 shipped. I asked if this was the cable that ran frome the main to the PC board or the cable that ran from the PC board to the T-Con. She couldn't answer that because their system is down. The connector on the main is K5LVDS, the connector at the other end is K7LVDS. The connectors on the PC board and the T-Con do not say LVDS. Am I correct in assuming that this is the cable I need? I can't find any reference to it online.