Sanyo dp42848. No picture no sound?has anyone found the problem

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

NO BUT I HAVE A 12 transformer

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

I want to use two 12v lamps connected in series and then connect them to the 24v output to really verify if you have the voltage or not for sure. Something does not make sense at this point.

[tom66]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Is it possible the transformer has an open winding?

It would be the first time I've seen one...

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Only if the center tap pin is open tne you will have no output, but I already have him check the resistance on all 3 pins, I myself never have to replace this kind of transformer in all my repair.

[drpj23]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Just out of curiosity, does removing the inverter from the power supply do anything for the 24v pins?

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

What is the rail wire?i unplugged the wire on the power supply upper left at top of power supply,the power supply Board read 24v so I probed that pin. No volts the wire that goes to that pin is white and goes to the invertor, tried on the slave invertor same thing,the other wires show lower voltage like 4.75. But no 24 volts with the tv on plugged in?so if I'm doing it right IS THE POWER SUPPLY TO BLAME?ok will wait up tonight for your reply, thanks

"i unplugged the wire on the power supply upper left at top of power supplythe power supply Board read 24v so I probed that pin. No volts the wire that goes to that pin is white and goes to the invertor,"
Hmm, I am trying to understand the statement above. I read it as no 24v with the inverter baord not connected.

[drpj23]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Sorry, I didn't realize he said that, this thing escalated to 106 posts rapidly so I was trying to rely on memory

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

I know, the thread is getting long, the circuit is so simple, transformer, rectifiers, filter caps- that is? the 12v is generated by the same transformer and it is putting out 12v OK. We are missing something simple here.

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Look I don't know anymore than anyone here,but something like a fuse or something has blown?when I plug that tv in and I probe the wires on the power supply there is no 24 volts! Something is shutting down the 24v side of the power board?should I reinstall the board?

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

How do I power up the backlights with a 24 volt sorce?

[tom66]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

You need a 24V, 8-10A power supply... if you have one, then provide 24V and connect INV-ON to 5VDC and DIM to 5VDC.

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Forget that idea I loaned the power supply

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Oh well I'm stuck I guess I will keep looking over this board,if anyone else knows what to do please post thanks

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Try this link very interesting could be the problem? http://www.justanswer.com/tv-repair/...hit-power.html

[tom66]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

I see Rick Williams answer on almost every part of Just Answer to be "it's the capacitors." Even to LCDs with blurring screens etc. It's complete nonsense. But he gets paid for it!!

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

I still like you to get the lamps for testing the power supply, like I had explained earlier, the T1 supply the 12v and 24V from the SAME transformer and same drive circuit, there is only one shutdown circuit in the primary side of the transformer, if it shuts down, the 12v will be off also.
Did you look to see how much the replacement board is?

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Well I plugged in the power supply to retest wires, now the tv shuts off after 3 seconds,it used to stay on all the time?

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Recheck all the connectors, also leave the cable un-connected to the inverter board (no connection on the 24V connector), see if it will come on.

[tomstr]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

Which inverter board master or slave?

[budm]

Re: Sanyo dp42848. No picture no sound?has anyone found the problem

The connector CN4 to the MASTER, and next to it that goes to the Slave on the power supply board where it is labeled with 24v, do not have anything plug into that connector.