Ham Radio
Ham Radio, Electronics, Software and more...

Home » Electronics » Repairs » Mitsubishi WD-62825 (GBLOD - Green Blinking Light of Death)
Mitsubishi WD-62825 [message #217] Fri, 25 December 2009 20:33 Go to next message
kc2nda is currently offline  kc2nda
Messages: 42
Registered: December 2004
Location: New Paltz
Member
I bought this television from someone I thought was an honest person. I don't blame him for wanting to sell his television. But the price tag of $1200 seemed like a great price since it was around $7000 brand new. He was trying to get rid of the television because he was buying a newer model. Of course when I got to his house both times to look at the television, it was on, and was working great. He did mention it didn't like the power to be disconnected. If it did, I needed to let it sit for about 10 to 15 minutes without the power plugged in, then I could turn it back on. Well, I think he was selling it because he knew it was going bad. As soon as I got it home, it didn't work. I finally got it to turn on, but a couple weeks later the power went out and the battery backup I had on it, discharged fully. Of course the green light was blinking AGAIN. This time, I could not get it to turn back on. Well, after a TON of research, I found a message board that had TONS of people with the same problem. http://www.techlore.com/forum/thread/20273/Mitsubishi-WD-628 25-Blinking-Green-Light/
It seems that there were bad capacitors in the unit. So I opened the television up and found only ONE cap that was buldged on the power supply. I replaced the cap and put it all back together. It turned on! BUT of course as soon as the power went out again, SAME PROBLEM. I finally purchased a good capacitor tester and took the television back apart. This time I went further and took all the boards out. I saw ANOTHER buldged cap
on one of the other boards. So I am going to check all the capacitors and post my findings.

You will soon see pictures here of my findings...
I used some pictures and repair notes from "TBULLY'S MITSUBISHI WD-62825 GBLOD AND PICTURE QUALITY REPAIR EXPERIENCE 11-10-2008" because my camera was not available when starting this repair. If you want this document, please ask at the techlore.com's website listed above. I hope to help by adding my experience as well. If anyone else wants to add their experiences or pictures, please do...

[Updated on: Fri, 25 December 2009 20:38]

Report message to a moderator

Re: Mitsubishi WD-62825 3.3V 5V Power Supply Issue [message #219 is a reply to message #217] Mon, 28 December 2009 23:40 Go to previous messageGo to next message
kc2nda is currently offline  kc2nda
Messages: 42
Registered: December 2004
Location: New Paltz
Member
I tested the 3.3V and the 5V test points on the power supply before stuffing everything back into the television. The problem is that the power supply at the 3.3V and the 5V test terminals don't have voltage. I have been testing all the components on the board and following the schematics from the service manual. It looks like from the manual, that the 3.3V and the 5V side become available when there is a voltage coming from the PON-2 lead coming from the DM board. I would have thought for sure that the power supply was bad. But I pulled the power supply out and traced and tested everything back to (I am ONLY assuming at this point) a missing voltage on the PON-2 lead on the K3 connector on the power supply coming from the DM board (PIN 4 on both boards). This is how far I have gotten so far. I supplied an external 5 volts to the PON-2 lead on the power supply and then ALL the relays activate and then there is the 5V and 3.3V. So I am going to pull apart the DM board ONCE again tomorrow to see if there is anything that I missed. Can anyone shed any light on what the PON-2 pin is and what voltage should be there? I would love to hear anyone that has had any same experiences...

Does anyone have good schematics for the WD-62825???? More than just a block diagram? Something that might have all of the capacitors, diodes, etc???? The service manual doesn't show all of the little details....
Re: Mitsubishi WD-62825 3.3V 5V Power Supply Issue [message #220 is a reply to message #219] Tue, 29 December 2009 20:10 Go to previous message
kc2nda is currently offline  kc2nda
Messages: 42
Registered: December 2004
Location: New Paltz
Member
Update: I traced back the PON-2 lead on the DM board and it goes directly to the IC7A00 processor which means the processor is not switching on the PON-2 lead. I checked all the external switches which should be easy enough to do.

The easiest way to check the switches to make sure they are all ready to turn on the set. Locate the LF pin header on the DM board 6th one in from the back of the WD-62825 unit. Each colored pin should have a black (ground) with it (except the red and white one). If you check continuity with your meter, each switch should be showing continuity. If any of them are open, you need to fix that first. If ANY of them are open, the unit will not turn on.

So I am still searching for the problem. I suppose I will test more caps on the DM board. I have not tested them ALL yet.
Next Topic: GeForce 7600 GT 1500uF 6.3V FZ71 - Bad Capacitors
Goto Forum:
  


Current Time: Thu Nov 23 17:21:06 EST 2017

Total time taken to generate the page: 0.03762 seconds