Need help troubleshooting Sanyo DP42848.

[Dragunbayne]

Greetings!

I have a Sanyo DP42848 that I got very cheap because it was broke. The people had taken it to an actual repair shop which diagnosed it as needing new inverter boards. This was very obvious as the boards looked horrible, I'm thinking they overheated. Anways, I replaced both boards with new ones and now it turns on with only the left side lighting up and then the backlight shuts off. I'm assuming the protection circuit is shutting off the backlight because of whatever is causing the right side to not light up. I am very skilled with electronics repair, but do not have a lot of experience with TVs. What I am thinking is I either got a bad inverter or the power supply is bad. Any guidance you can provide to help with troubleshooting is greatly appreciated.

[tom66]

Re: Need help troubleshooting Sanyo DP42848.

Check that you've got a good +24V going to the inverters.

[budm]

Re: Need help troubleshooting Sanyo DP42848.

If there two inverter board, on on the left, and one on the right, then that sounds like one of the inverter board is not working (or not connected properly) when you only see half side of the screen lit up by the lamps.

[Dragunbayne]

Re: Need help troubleshooting Sanyo DP42848.

Check that you've got a good +24V going to the inverters.

Yes 24V going to each board.

All connections and wires are good also.

Edit: Also do any of you happen to know how many lights are in this panel? I've been looking at it more and I'm starting to think the top and bottom on the right side is lighting, but not the right edge itself.

[Dragunbayne]

Re: Need help troubleshooting Sanyo DP42848.

Yes 24V going to each board.

All connections and wires are good also.

Edit: Also do any of you happen to know how many lights are in this panel? I've been looking at it more and I'm starting to think the top and bottom on the right side is lighting, but not the right edge itself.

Hey all looking for some more help on this one. I have replaced both inverter boards with new ones.

[freakaftr8]

Re: Need help troubleshooting Sanyo DP42848.

my best guess would be one of the bulbs are not lighting up inside the TV causing the tv to shutdown. look inside behind the screen and see if every bulb is lighting up that be my best guess to start with

[budm]

Re: Need help troubleshooting Sanyo DP42848.

If you can get the model number sticker on the LCD panel, then you can look up the spec sheet, it will give you some idea as to how many lamps are in your LCD panel assembly. The symptom you are seeing with the Master/Slave inverter setup is that on of the inverter is not working.

[Dragunbayne]

Re: Need help troubleshooting Sanyo DP42848.

Found the issue. Decided to get ambitious and took the panel apart. One of the ballasts for ccfls was sparking. Somehow the trace grounded out in one spot. We cut the trace and jumped it with a wire and hooked it all back up. The lights kick on completely now, but only for a couple of seconds, but this is likely due to one of the lamps being bad. A new lamp is on the way and should be here the end of the week. Thanks for the help, I will update when I get the new light!

[Dragunbayne]

Re: Need help troubleshooting Sanyo DP42848.

Found the issue. Decided to get ambitious and took the panel apart. One of the ballasts for ccfls was sparking. Somehow the trace grounded out in one spot. We cut the trace and jumped it with a wire and hooked it all back up. The lights kick on completely now, but only for a couple of seconds, but this is likely due to one of the lamps being bad. A new lamp is on the way and should be here the end of the week. Thanks for the help, I will update when I get the new light!

Got the ballast repaired and the replacement bulb in. All the lights lit up fully finally. After letting the new lamp burn in for awhile, we reassembled the TV and everything works great! Thanks for all of your help.