Sanyo DP50747-04 (Chassis 04)

[kevinm34232]

This is my next project, I had found a service manual before I bought it but apparently there are several chassiss designs, could not find the IC's listed to troubleshoot guess the main board is different. Anyone have this?

[selldoor]

Re: Sanyo DP50747-04 (Chassis 04)

You dont say what the problem is but I hope its not this
https://www.badcaps.net/forum/showthread.php?t=14202

There are other threads on here as well if you havent already seen them.
No SM sorry

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

The problem is the same as the Sanyo DP46840 that has the bad audio IC. It turns on then shuts off after a few seconds. No video displays in between.

[budm]

Re: Sanyo DP50747-04 (Chassis 04)

Any luck disconnecting that Diode to see if the TV will come on and stay on? I will not be surprised if they will use the same board (stuff it differently for the 50" version)

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

I cannot find a service manual for the Sanyo DP50747-04 (Chassis 04), but having same power failure circuit as this one:

https://www.badcaps.net/forum/showth...=sanyo+dp46840

Without the service manual I don't know what IC's to check voltages on. Is this going to be possible to diagnose??

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

Did some more digging and found another Sanyo model using the same main board, found a S/M:

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

OK checked voltages in PF circuits, appears everything seems to be good except IC6051. I have 5v in pins 1 and 2, 0.6 on where I have my test lead (Supposed to be 3.3v). The same regulator below that one has 2.6v out. Am I checking the correct pin for output?

Datasheet for that IC:

[tom66]

Re: Sanyo DP50747-04 (Chassis 04)

It looks faulty to me. High on pin 2 means regulator is switched ON, and there is a sufficient input voltage. What is the voltage between pins 3 (tab) and 4?

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

Not sure what you're asking me to check?? I have 0.6v on pin3 and 0.2v on pin 4.

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

So replaced IC6051 with same result. I guess I should have isolated pin 6 first to check it. When I remove pin 6 from circuit I have 5v on pin 6. So it seems there is something else wrong in that circuit. Can someone look at the s/m I posted a link for and tell me what this circuit is for?

[tom66]

Re: Sanyo DP50747-04 (Chassis 04)

Pin 6 is the output. So something on the board is shorted to ground.

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

Would I be correct that this regulator is feeding this IC6504?

Im trying to isolate whatever chip IC6051 is feeding voltage to, I see IC6051 outputs A3.3v, and IC6504 shows A3.3v coming in. In the photo below, where the 3.3v is coming into IC6504 it shows a capacitor C6518 inline before. I removed that cap and still have the short. Am I going about this correct or am I way off?

[RON_CET]

Re: Sanyo DP50747-04 (Chassis 04)

on page 30 of your service manual of block diagram it will show you all the connections of where your (a3.3) will connect.then using your schematic on page 57 and lift componets which are tied to the (a3.3) line until short goes away then you can better isolate to defective componet. the most common problem i've seen with this when the (a3.3) line has short on it is where the HDMI switch ic6504 has been damaged,seen also cases where the top of ic blown off

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

Thank you. So by looking at page 57 would removing C6518 isolate IC6504? I see pins 23 and 55 getting the A3.3v I was trying to avoid cutting the traces on the board. I didn't see any other places on page 30 getting a3.3.

[RON_CET]

Re: Sanyo DP50747-04 (Chassis 04)

no removing c6518 will not isolate ic6504 but desoldering one side of the coil L6516 or L6515 would
also if short still present after lifting coils L6516 or L6515 also find coil L6518 which also feeds (a3.3)to ic6504
next if ic6504 is confirmed OK lift coil L5541 this connects to ic5500 then see if short has gone

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

I lifted one side of L6515 no change, then did L5541, output went to 1.5v on IC6051 but still low and shut down.

[RON_CET]

Re: Sanyo DP50747-04 (Chassis 04)

set not going to stay up and run with (a3.3) removed from any of the locations lifted what your trying to accomplish here is to get the (a3.3) line to go from a resistance short from 0 ohms to very high resistance

also you do realize if it turns out to be a flat pack ic and unless you have very specialized desoldering tools the only way to salvage this set would be main board replacement

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

Yes I do realize that, and Im sure Im going to have to replace it after I'm done anyways. Im just trying to troubleshoot down to the component that's bad for my own knowledge, and I appreciate the help from you. So, now that I have L6515, L6516, and L5541 desoldered, what exactly am I checking now, resistance from where to where?

[RON_CET]

Re: Sanyo DP50747-04 (Chassis 04)

go back to your source supply @ ic6051 read the output pin 6 to ground to see if lifting any of the componets to those area has changed the short on the source line? if not must keep chasing until the short goes away to very high resistance other than 0 ohms or the short to ground

[kevinm34232]

Re: Sanyo DP50747-04 (Chassis 04)

OK you're right with everything installed I have a ohms reading of 0.001 from pin 6 to ground. When L6516 removed it goes to 1.096. I think when L5541 was removed I had more of an infinite reading.