Sanyo DP55441 Strange Picture and Sound

[gostmn26]

One of my college professors wanted me to see if I could fix it. She got it from a friend, that told her it just didn't turn on one day. Other than that she knows nothing about it.

I brought it home and determined it was the power supply. There was a mosfet blown out (EL122, Q102). There was also a spot on the back of the power board that goes from FB103 to Q101 that is burnt out. On top of this C112 and Q106 are bad as well. I replaced the power board and the TV now turns on. I am wondering if it had a power surge or lightning hit.

The problem I am seeing now it a screen that is unreadable, even the menu is (see attached picture). This leads me to believe a bad LCD panel. Then there is also the volume, I have hooked the TV up to our cable box and coax and get the same sound. The sound coming out isn't very loud and it is all static sounding, drowning out the voices.

Due to the problem with both the picture and sound I am now leaning towards the main board. I am looking for some assistance in determining if this is the case.

Thanks,
Michael

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

The problem I have is I don't understand schematics enough to know where to check the mainboard. I am looking for some assistance on where to look for both sound and video output.

I haven't found similar problems with both sound and video being scratchy. I have seen some with similar pictures and it being either the TCON or bad panel. This wouldn't explain the sound or the fact that there are no horizontal or vertical lines.

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

I have a few more pictures of the TV, and am waiting to get help trying to figure out what the next step is. I am unsure about how and where to go about testing the main board sound.

For some reason the pictures for the TCON are not coming out clear. I have taken about 20 different ones of it and all are the same. I have disconnected one side at a time, when one side is disconnected there is no picture at all.

Here is a link to a video of the sound and picture. Let me know if it doesn't play, I signed out of my amazon cloud and it played for me.

Thanks, Mike

[budm]

Re: Sanyo DP55441 Strange Picture and Sound

Can we get good focus pictures of the T-CON board? The third picture.

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

Thanks for the response, and I was finally able to get a clear picture of the TCON. For some reason my camera would not focus on this board, and 40 pictures later this is what we have.

[budm]

Re: Sanyo DP55441 Strange Picture and Sound

OK, please check the dcv at those test points GMA1~18 on the T-CON board.

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

Here's the readings I got for these points.

GMA1: 15.75
GMA3: 13.65
GMA4: 12.99
GMA6: 11.99
GMA7: 10.11
GMA9: 8.24
GMA10: 7.66
GMA12: 5.94
GMA13: 4.05
GMA15: 3.05
GMA16: 2.39
GMA18: 1.02

[budm]

Re: Sanyo DP55441 Strange Picture and Sound

They do not look bad.
You also indicate static sounding, that will be main board problem.
Did you already try reseating the cables/connectors, etc.
No sign of damages on the main board at all?

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

There is no visible damage that I can see on the main board. I bought a can of contact cleaner and sprayed all the cables. I was thinking main board as well due to the sound issue.

Here is a video of the sound and picture.
https://www.amazon.com/clouddrive/sh...hare_link_copy

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

I am looking at getting a mainboard for this TV. The mainboard on this TV has the number 431C4169L02 on it, I am assuming the L02 on the end is a series number. I am asking because seems to be a hard one to get. Could I purchase 431C4169L03 board for this?

[kev1n69]

Re: Sanyo DP55441 Strange Picture and Sound

Version swap is a crap shoot. Maybe maybe not if you can match versions and panel#and or tcon maybe do any other suppliers have a cross ref for this model /board

[kev1n69]

Re: Sanyo DP55441 Strange Picture and Sound

Wish i could see the vid you posted i got one of these with distorted picture but sound is ok and it clears up after 15 min run suspect bad caps but havent got into it yet to check just curious if pix problem is the same

[kev1n69]

Re: Sanyo DP55441 Strange Picture and Sound

The still shot looks like main but definatly not conclusive just guessing due to tcon voltages

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound

Here is what I have done with this so far. I purchased another mainboard and had the same problem with sound and video. Being frustrated, I was looking at both power boards I have. The new one I bought and the bad one, this is when I noticed a difference. There were 2 extra coils on the top left of the new board. I also noticed the voltage for the audio was outputting 24volts, instead of the 12 volts on the old one. I realized the board I purchased was actually not what it was supposed to be. The board I got was for DP55441 v4 and not the v1 I have. I bought a different power board and the sound is fine now.

Now I still have the problem with video. I am wondering if it's possible the TCON is bad. Is there something else I can check to be sure?

[kev1n69]

Re: Sanyo DP55441 Strange Picture and Sound

I have very similar if not exact symptom on this model except sound is ok found both inputs to the tcon had corosion (microscopic) cleaned with contact cleaner on both male and female jack and socket, used q-tip soaked on male side smeared lightly the male side with a dielectric grease to prevent further corosion pix restored to perfect.

One of my college professors wanted me to see if I could fix it. She got it from a friend, that told her it just didn't turn on one day. Other than that she knows nothing about it.

I brought it home and determined it was the power supply. There was a mosfet blown out (EL122, Q102). There was also a spot on the back of the power board that goes from FB103 to Q101 that is burnt out. On top of this C112 and Q106 are bad as well. I replaced the power board and the TV now turns on. I am wondering if it had a power surge or lightning hit.

The problem I am seeing now it a screen that is unreadable, even the menu is (see attached picture). This leads me to believe a bad LCD panel. Then there is also the volume, I have hooked the TV up to our cable box and coax and get the same sound. The sound coming out isn't very loud and it is all static sounding, drowning out the voices.

Due to the problem with both the picture and sound I am now leaning towards the main board. I am looking for some assistance in determining if this is the case.

Thanks,
Michael

[chrismurphy]

Re: Sanyo DP55441 Strange Picture and Sound

Looks like a T-con board issue ,replace it first

[gostmn26]

Re: Sanyo DP55441 Strange Picture and Sound (SOLVED)

Ok, so I finally fixed this TV!
If I had hair I would have pulled it out when I figured out what it was. I Purchased a TCON for it and it didn't work. Like I said I went to grab my hair but it's shaved. I took the connecters from the mainboard off and I noticed something when I put them back on. On the connecter on the left there is a yellow wire farthest to the left, that came out of the connector. It took a bit because it was bent, but I got it back in. I plugged the TV in and it worked.

Now I had purchased 2 power boards, the one from Ebay was the wrong one. I even went and looked and what they sent is not what was listed. Then a main board and finally a TCON. I am willing to bet it was this wire causing the picture problem the whole time.

I'm still new to this Kev1n69 but that is something to look at, since you stated you have one just like it.