Sanyo DP50749-01 wont power on

[andyfisk]

Hey everyone,

I've got a Sanyo DP50749-01 that stopped working. I press the power button, can hear the relays click, the power led (front facing LED) is lit for 5 seconds, then turns back off. No picture, sound, or backlight attempt... I can do this 3 times before i have to unplug it and plug it back in (if I dont, pressing the power button does nothing).

Looking for the procedure to force this tv into powering up and running test patterns, a service manual, or any further advice on troubleshooting.

Main Board: Sanyo 1AA4B10N22900
X and Y Sus boards are both LG
Power Supply: PSPU-J806A

Thanks for any help!

[MagicSmoke]

Re: Sanyo DP50749-01 wont power on

Need a closer pic of PSU. The 3 caps on top right appear to have a stain on them or is it magic marker?

I just recapped a similar psu out of a DP-50747 and replaced all of the caps except the 2 large brown ones. It had same problem would not power up.

[andyfisk]

Re: Sanyo DP50749-01 wont power on

Most of the caps on the power supply are marked with what looks like a sharpie/black marker.

I already replaced IC1670, IC5730, IC1640, and IC1630 on the main board, but that did nothing. Same symptoms before and after new chips were put in.

Thanks for the response,
-Andy-

[MagicSmoke]

Re: Sanyo DP50749-01 wont power on

Unplug power cable to Y sus then try power on. If psu will stay on then Y or Z sus is faulty.

[andyfisk]

Re: Sanyo DP50749-01 wont power on

Unplugged cable running from power supply to y sus, tv does nothing when pressing power button. Plugged y sus back in and unhooked z sus from the y sus board. Tv will then power on and display the same issues as above.

[tw2005]

Re: Sanyo DP50749-01 wont power on

the boards are the same a the PQ30 and there is a training guide. for test pattern

(1) Disconnect the Main board from all connectors. Apply AC power.
Since P813 is not connected to the SMPS, the set will come on.
Short the two pins on the Auto Test Pattern lands.
If there is a picture of cycling colors and patterns, the Y-SUS, Y-Drive, Z-SUS, Power Supply, Control board,
X-Boards, TCPs and Panel are all OK.

[andyfisk]

Re: Sanyo DP50749-01 wont power on

I disconnected all cables from the main board, shorted the 2 auto pattern solder pads and plugged in the unit, it tries to power on 2 times (can hear relays clicking), then stops. Pressing power does nothing, disconnecting the power cord and re plugging it in restarts the 2 try cycle. Looks like it could be one of the aforementioned boards...

I will do some googling on the PQ30 to see what info i can bring up.

I really appreciate all the input.

Thanks!
-Andy-

[andyfisk]

Re: Sanyo DP50749-01 wont power on

After probing around with the multimeter I noticed F801 on the PS was bad. I've found a repair kit for the PSU-J808A board, but I have the PSU-J806A board. Havent found much info on it, but they appear to be the same board.

Any comments?

[MagicSmoke]

Re: Sanyo DP50749-01 wont power on

EAY58316301 Is this the P/N on the sticker?

You can solder a glass fuse of the same amps, to the blown one on the board. Sometimes they can blow from a power surge. If it blows again then bad diodes or Fets or other problems are indicated.

Shorts or other problems on X or Y boards can blow psu fuse.

Also google dim bulb tester for checking for shorts on PSU's.