Sanyo DP52848 Does not turn on

[The Mad Scientist]

Hello every one my name is shawn, this is my first thread/post. I am wandering if anyone knew where i could obtain a service manual for this Sanyo DP52848 lcd tv. The tv psu is receiving the turn on voltage from the pson but is not sending any voltage through the 12 and 24 volt outputs of the board.I have noticed a 10 volt signal and a .4volt signal on the secondary part of the board but have nothing on the primary side of the board.

[PlainBill]

Re: Sanyo DP52848 Does not turn on

No luck of finding a service manual. Without one you have three options. There is a power supply available on eBay for $69, free shipping.

A second approach would be to do some basic troubleshooting. Very broadly, there are four possible causes for this problem.

1. The PSON signal is not getting to the PFC and main SMPS controllers and turning them on.

2. The main SMPS controller has failed.

3. There is an excessive load (probably from a shorted diode) on the secondary of the SMPS transformer, causing the current limiting of the controller to go into protect mode.

4. An external load is causing the SMPS to go into protection mode.

A quick and dirty test is to check the voltage across the main cap. If it reads about 375-400 volts when the TV is supposed to be on, the PFC is working, the PSON signal is getting through.

The second test is to disconnect all output cables from the supply and use a 3.3K resistor (2.2K - 4.7K should be good) between 5VSB and PSON to turn on the main supply. If it turns on, suspect a problem in one of the loads.

PlainBill

[nuryev]

Re: Sanyo PDP50XRDA no picture no sound

Hi

I am trying to help a friend whose Sanyo tv suddenly stopped displaying picture and sound. The tv does power up as the pilot lights turn red (Standby) to blue (on). I have successfully repaired a Philips plasma so when asked to assist I took on the challenge.

Initially, the tv would switch on from standby blue light would flash and then after a few seconds there would be a soft click and red light would come on again. Since replacing some caps in ps this return to stand appears to have been resolved. Still no picture and sound though.

The owner of the tv did mention there was a power outage in the suburb probably due to lightning strike - on closer inspection of the circuit boards - i noticed one of the chips on the main logic control board has what I can only describe as a 'surface irregularity' - something i have seen on a driver chip on a cd player after a capacitor popped.

Any advice, directions would be appreciated.
Thank you.