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

[budm]

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

First using Ohm mode to check the resistance between those pins of the transformer to see if it has open windings, it should show really low ohms.
Second, we will test the rectifiers by setting the meter in Diode testing mode. please see the notes on the picture.

[tomstr]

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

7.75 on both circuits, not voltage oms

[budm]

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

"take the reading between pin 12 and 13, and 12 and 14 of that transformer T1"
Can you verify the reading of the transformer?
12 & 13 = xxxx Ohms
12 & 14 = xxxxx Ohms.

Then in Diode mode reading of the two rectifiers for the 24V?

[tomstr]

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

I dont thik my meter has diode function?

[budm]

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

Can I see the picture of the meter?
So you are reading 7.75 Ohms on the transformer? I do not expect it to be that high at all.

[tomstr]

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

The readings are 7.75 for both

[budm]

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

Is the meter set to 2K Ohms as shown in the picture, if it is that means it is showing 7.75K ohms (7750 Ohms!).Set it to '200' Ohms range and take the reading again. I expect it to be less than one Ohm. What resistance do you get when you short the meter leads together?
Your meter does have Diode mode.
I also drew up simplified diagram, as you can see, there is not much for the 24vdc section at all.

[tomstr]

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

Set meter to 200k. Readings-1.0 on all points on cathodes

[selldoor]

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

Budm did not say 200k ohms he said 200 ohms

[tomstr]

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

Ok i will set meter to 200 ohm and let u know

[tomstr]

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

Im going to be home half day so i can spend the afternoon on this tv YOU PEOPLE HAVE BEEN VERY NICE AND HELPED ME ALOT THANKS

[budm]

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

Set to 200 to verify the resistance of the transformer windings. That resistance reading of 7.75 Ohms/K Ohms is not right at all.
Set to Diode mode to test the Diode that I asked to check.
Please go on line and learn how to test the Diodes and resistance.
Right now we have narrowed it down to the 24V output section, the 12v is owrking so the T1 section for the 12v and the driving circuits are functionong OK, only the 24 section is not right, especially the DC resistance reading of 7.75???? is not right at all.
I am getting a little frustrated right now on giving the instructions to follow with all the pictures and the diagrams that I had provided so far.
May he should by a new board and get it over with.

[tomstr]

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

Will do i a couple hours

[tomstr]

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

Im trying to follow all suggestions,im goingas fast as possible !!!HELP im going to narrow down in a few,someone sent me a pic of some digram but not sure how to read it?so MABEE I SHOULD JUST GET A POWER SUPPLY?let me know....

[tomstr]

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

Just found out how to test diods i will do it tonight

[budm]

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

I need that reistance reading of the transformer for sure, may be johnboy1313 can give us the reading from his TV transformer T1 reading.

[tomstr]

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

Ok will do will get back i a hour just got home

[johnboy1313]

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

My readings are listed in the link I provided. The TV is back together and hanging on the wall. I'm probably not going to take it down and open it back up until there is a fault of somekind. I don't know though, crazier things have happened.

[tomstr]

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

Ok again tested circuit t.1 set meter at 200 ohms NOT 200k ohms is 00.9 on 12-13 and 00.9 on 12-14 IS THAT WHAT YOU NEED?

[tomstr]

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

Hey about the skeches on the circuit,which way is the board lying down,not sure were to start don't know how to read scamatics?