Sanyo LCD TV DP26649

[thetonywarren]

Ok guys, this is my first post so please be nice.

Im not a complete noob, I have repaired numerous monitors with bad caps, but mainly only because I could tell that they were bulging or visually bad.

I dont really know much about these circuits, but I am proficient with a DMM and have all the tools needed to test/repair....

I am pretty good with soldering new caps in and other components from a lot of practicing. I am very familiar with electrical concepts but not so much with electronics. I am familiar with testing continuity, resistance and capacitance as well as ac and/or dc voltages.

Im going to start with this TV as I am trying to fix it for a friend.

The tv has a green light on the front when the power button is pressed, but no reaction from the backlights. The capacitors look good and I replaced a few just to be safe, but still have the same results. I dont know where to start in troubleshooting further. Can you guys help. Please let me know. I can provide more pictures if necessary.

Thanks!!!

[Mr Bill]

Re: Sanyo LCD TV DP26649

Does the green LED stay on or does it turn back off after a couple seconds?

[thetonywarren]

Re: Sanyo LCD TV DP26649

It stays on.....until I press the power button again.

[Mr Bill]

Re: Sanyo LCD TV DP26649

Turn the tv on in a very dark room and shine a flashlight through the screen. I put the flashlight directly over the screen in about the middle of the panel. Then hit the menu key and hopefully you'll see it. You could also move the flashlight lower and hit the volume key and try to see that. Try and get a very bright flashlight if possible like a mag-lite.

[thetonywarren]

Re: Sanyo LCD TV DP26649

ok, I think I know where you are going with this. You want to see if the main board is working but the backlights aren't.

I did this and it doesnt look like I can see any image at all.

[Mr Bill]

Re: Sanyo LCD TV DP26649

Try it with a source hooked up to it. It can be a pain sometimes. Do you get audio when a souce is hooked up?

[thetonywarren]

Re: Sanyo LCD TV DP26649

No audio, no sign of any video either. hooked up hdmi source, also cable tv source no dice.

[Mr Bill]

Re: Sanyo LCD TV DP26649

With the tv on set your DMM to DC volts and list what voltages are present. List them like so

5v - 5.02
12v 12.23
24v 24.34

ect ect..... I upload a picture of the 2 connectors you'll be checking.

[thetonywarren]

Re: Sanyo LCD TV DP26649

5v - 5.01
12v - 11.96
24v - 24.28

[thetonywarren]

Re: Sanyo LCD TV DP26649

I know I didnt list every single reading, but they are all veeeerrryyy. similar, nothing seems to change drastically at any point.

[thetonywarren]

Re: Sanyo LCD TV DP26649

BTW, thanks for helping me with this.

[Mr Bill]

Re: Sanyo LCD TV DP26649

what is the pson voltage?

[thetonywarren]

Re: Sanyo LCD TV DP26649

PSON - 5.00vdc

[budm]

Re: Sanyo LCD TV DP26649

I fixed this model before, if you disconnect K8L connector and the backlights comes on, then you have problem with the main board.
http://s807.beta.photobucket.com/use...ml?sort=6&o=21
K8L has the BL_ON signal that turns on the Backlights.
Try it and see what happen.

http://s807.beta.photobucket.com/use...20TV%20DP26649

[Mr Bill]

Re: Sanyo LCD TV DP26649

Did you get 24v on CN903? It's the connector on the right of the pic i posted earlier. From what i see it appears your power supply is turning on correctly and it's getting the right pson voltage from the main board.

[thetonywarren]

Re: Sanyo LCD TV DP26649

Yes, I did check CN903, 24v is there on pins 1-5. I did disconnect K8L and the backlights did come on.

What can I do to troubleshoot the main board?

[budm]

Re: Sanyo LCD TV DP26649

I did not try to fix my main board either, no diagram. I can only check some voltages and that's about it so I replace the board instead.

[Mr Bill]

Re: Sanyo LCD TV DP26649

The part number for the main board is on a sticker that is on the tuner. It'll be something like N7HG.

[thetonywarren]

Re: Sanyo LCD TV DP26649

the main board is a N7GE

[thetonywarren]

Re: Sanyo LCD TV DP26649

does anyone have any information or guidance on repairing the main board for this??

It is a Sanyo DP26649 and the main board is a N7GE, I would like to attempt to repair instead of trying to find a new main board.

Thanks!!!