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

[tomstr]

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

Ok left it unplugged,and the unit,is it possible it's the fail safe circuit ?

[tomstr]

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

I don't mind buying a power supply if I knew for sure if that's what it was?

[selldoor]

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

Fawn gray and brown?

The component you referred as "Pink" in post 82

[selldoor]

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

Budm - dont know if you remember this one. Sanyo 46840 so different and not a felta board but similar problem.
https://www.badcaps.net/forum/showth...dp46840&page=4

Turned out Kevin had a problem with the Audio which was fed from the 24v and caused the whole thing to shut down - Any chance it could be the same on this?

[tomstr]

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

IM NOT GIVING UP ON THIS! HOW ARE WE GOING TO LERN ANYTHING IF WE JUST BUY A BOARD?SEEMS TO ME IF WE FIND THE BAD CIRCUIT THEN IT WHOULD BE A CHEEPER FIX AND WE COULD LERN SOMTHING IN THE PROCESS? So what should i do next?

[tom66]

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

First calm down.

This power supply generates the 24V and 12V using the same part.

It is considered essentially impossible for just the 24V to fail.

Some error must be being made somewhere, either in how we are directing you to test or in how you are testing.

Quick question, are you using DC200V to test 24V? Maybe your meter is over-ranging and you are seeing this as zero.

[fparker121]

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

Hey,
I know I am late in the thread But I am having the exact same problem with my tv as well. It is the same model number the dp42848, So I am trying to keep up with the updates. I opened the back case and found all my boards to be brand new looking like they should be. I will keep following along and hopefully we can all solve this together. Thanks

[budm]

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

"First calm down.

This power supply generates the 24V and 12V using the same part.

It is considered essentially impossible for just the 24V to fail.

Some error must be being made somewhere, either in how we are directing you to test or in how you are testing.

Quick question, are you using DC200V to test 24V? Maybe your meter is over-ranging and you are seeing this as zero."

I cannot say it any better Tom. 12V is working, and as you can see in my diagram, there is not much in the 24v section. He will have to use scope to look at the AC waveform of the 24v windings to see if it is there.
I still want to use the lamps for verification for sure, but getting no where with my suggestion. I am out of here.

[tomstr]

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

I will be working this afternoon,tonight i will try to post tonight,iI WILL FIND OUT THIS THING ONCE AND FOR ALL.i will start over square 1

[johnboy1313]

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

To the original poster. At this point, it may be time to pull back and rethink things. I recently got a little over anxious and turned a few dollar fix into a 50 dollar fix all because I wanted to get out of my comfort zone without taking time to research. You may be better off storing this thing and keeping an eye on Craigslist for the same tv with a cracked panel for cheap. That way, you will have all of the boards to swap out one at a time until it is working. At that point, you may be able to recover some of your investment parting out what is left. Good luck.

[tomstr]

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

First thing the tv is plugged in powerd on DOES NOT CUT OFF AFTER 3 SECONDS,IT WAS STAYING ON BUT NO BACKLIGHT...then with the tv on i whould probe the circuits,with the plug in the connector. Using the 20 d/c setting on my meter,THEN TESTED THE 24v circuit on the board 0 volts..and the lower wires on the plug had 12v 5 v ect BUT NO 24v,SO NOW AFTER INSTALLING THE BOARD BACK IN AFTER OTHER TESTING,the tv SHUTS OFF AFTER A FEW SECONDS?WHY I DONT KNOW!!

[selldoor]

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

Please stop using capital letters are you using a pad? If you test 24vDC with the meter set on 20vDC depending on the meter it might show as 0 as it is overscale/ out of range

[tomstr]

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

Sorry about caps.... I will change my d/c voltage setting on my meter..its more than likley wrong..will get back..will start over

[tomstr]

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

I talked to a friend that works on tvs he told me that its going to be 1.the power board or slave invertor...he has seen this over and over...so im going to let him look at the power board tonight..i will post a s a p...

[budm]

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

Please stop using capital letters are you using a pad? If you test 24vDC with the meter set on 20vDC depending on the meter it might show as 0 as it is overscale/ out of range

Finally after over 100 posts,
I think selldoor figured out the problem why it is not showing 24v on the meter, if he put the meter in 2v scale and try to read 12v output, I would think it will report wrong reading also. I believe now that the 24v is OK. Do not understand why it is set to 20V scale when you are trying to measure 24V.

[tomstr]

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

Ok i have a 24 volt power supply how do i use it to power up the invertor?

[tomstr]

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

Im going to use a diffrent meter,i have tryed 2v 20v 200v no voltage is output i may have a bad meter or i have no 24v output?

[drpj23]

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

Ok i have a 24 volt power supply how do i use it to power up the invertor?

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. [per TOM66]

I guess your friend didn't say anything new?

If you want to test your meter you have a reference with your powersupply for 24v.....at least human error is almost completely ruled out that way.

[tom66]

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

Note -- Do not try to use a truck battery. They put out 28.8V, the inverter will most likely shut down due to over-voltage protect.

[tomstr]

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. [per TOM66]

I guess your friend didn't say anything new?

If you want to test your meter you have a reference with your powersupply for 24v.....at least human error is almost completely ruled out that way.

Sorry getting back so late,my tv friend was not home yesterday,i am gonna try sunday,i goin to work today.im going to test the slave invertor tonight. Im not sure were the circuits are located? On the board?can you let me know were to attach the 24v so i can power backlights? Ok thanks