Mitsubishi WD-65733 Main board caps

[weimars]

I've got a Mitsubishi Wd-65733 w/ main board part # 934c260002. The tv will not power on and just has a constantly blinking green light on the front. The light and ballast are fine, the power supply tests fine as well. I think it is in the main board, is there something to look for on this to get it to turn on? The troubleshooting codes give nothing to go by.

[newtothis]

Re: Mitsubishi WD-65733 Main board caps

Ok first question... Do you have much experience in diagnosing electronic faults?

[RON_CET]

Re: Mitsubishi WD-65733 Main board caps

Timer LED Does Not Stop Blinking
Cause 1
1. Suspect the Main PCB part # 934C260002

you want be able to put set into on board diagnostic mode because the set is not able to go through and complete the boot cycle this why you have the continues flashing of the light. Normal operation light would quit blinking after about 60/70 secs then power on would be allowed, main board replacement only option and don't forget to consult service manual cause after board replacement your going to have to enter service mode and copy over the alignment data and geometry data from optical engine back to new main board

[weimars]

Re: Mitsubishi WD-65733 Main board caps

@newtothis ... I believe I have reasonable abilities. What did you have in mind?

@RON_CET ... I have the service manual but I'm not sure how to put set in diagnostic mode to complete the boot cycle. I agree with the normal light operation as this is my personal tv that I use regularly, it would let you power on after 60/70 secs. How would you be able to retrieve the alignment data and geometry data (assuming through the diagnostic mode)?

[RON_CET]

Re: Mitsubishi WD-65733 Main board caps

going into diagnostic mode will not complete boot cycle, i was just explaining that you can't go into diagnostic mode until the boot cycle completes it loading sequence hence light stops blinking, here's snap shot of some reading from page 32 of service manual which tells you about transferring the data once new main board replaced

[weimars]

Re: Mitsubishi WD-65733 Main board caps

I understand now what you meant. Is there any repair to the original board (i.e. replacement of caps) that you see being possible? Or buy a used one from ebay. Or buy new (reconditioned)? Is there a certain part of the board that I should look first for diagnosing a possible fault? Thanks

[newtothis]

Re: Mitsubishi WD-65733 Main board caps

Voltage regulators can be tested, but main boards are not an easy repair and replacement is advised

[RON_CET]

Re: Mitsubishi WD-65733 Main board caps

As a Authorized service for Mitsubishi I'm not aware of any quick fix tips for this issue,board replacement for the blinking issue is a Mitsubishi Tech triage recommendation
from Technical center. as for purchasing board ShopJimmy, Paylesscomponets,union Electronics,Encompass I'm not big fan of buying off Ebay most of the Sellers have no way of testing what there selling so you 50/50 chance unless there giving a decent return policy on DOA items

[weimars]

Re: Mitsubishi WD-65733 Main board caps

I've purchased things from them before. There's not much of a challenge in just replacing a board. If that's what it ends up being I suppose I will.
I've checked a couple of the regulators, fuses are good as well. There are a few test points labeled with voltages that seem to be ok. Is there other things to be looking for.

I've heard the caps on the board can be a big problem and if I replace all of them (99 I think) that should allow the set to complete the boot sequence. I'd try and tackle that if there is some truth to it. I remember there was no sign of this problem occurring before it just happened. I had tried to turn on the tv when I noticed that the timer light was constantly blinking with no response.

[mmartell]

Re: Mitsubishi WD-65733 Main board caps

How do you know the lamp and ballast are good ?

You sound like a capable fellow - if these are electrolytic caps I would by an ESR meter instead of 99 caps and future proof yourself against further issues of the same type and only replace what's necessary.

[weimars]

Re: Mitsubishi WD-65733 Main board caps

I was able to send a signal to turn on the ballast and the lamp started to light, but with no fans running I let it turn off. I replaced the lamp recently (1-1.5 yrs) and I used a Osram lamp that has worked really well.

I don't have an ESR meter. Would I be able to test them on the board? If I had to take them off to test, I'd probably go ahead and replace anyway. What ESR meter would you look at buying? I do like to have nice equipment, but I don't have to have the best of the best. I just want it to give me an accurate measurement everytime.

[mmartell]

Re: Mitsubishi WD-65733 Main board caps

Yes you can test them on board, but it is still preferable to remove them for testing unless you have a good idea of the circuit they are a part of but keep in mind those caps you're looking at will likely not have signs of damage they will have high esr and this will be detectable in circuit.

There is this

https://www.badcaps.net/forum/showthread.php?t=32989, though it gets convoluted at times

and this

https://www.badcaps.net/forum/showthread.php?t=32989 to get you started.

Good luck.

[weimars]

Re: Mitsubishi WD-65733 Main board caps

Yes you can test them on board, but it is still preferable to remove them for testing unless you have a good idea of the circuit they are a part of but keep in mind those caps you're looking at will likely not have signs of damage they will have high esr and this will be detectable in circuit.

There is this

https://www.badcaps.net/forum/showthread.php?t=32989, though it gets convoluted at times

and this

https://www.badcaps.net/forum/showthread.php?t=32989 to get you started.

Good luck.

Your links go to the same page. Did you have a different thread in mind?

[mmartell]

Re: Mitsubishi WD-65733 Main board caps

Oops I did, yes. Just search for threads with "esr" in the title and you will find them.

[weimars]

Re: Mitsubishi WD-65733 Main board caps

I was going to replace a few caps on the main board in an effort to rule out a few suspects. I've read a few forums here that suggest using Panasonic FR (FM, FC...) series caps for the ultra low esr. I've got some Rubycon PX series (through hole) caps that was going to use. My question is are they not a low enough esr to function properly?

Second question: There are many caps that have similar ratings (i.e. 6v 47uf, 16v 100uf, 16v 10uf...), can I use one size cap that would accommodate the bulk of these caps (i.e. 16v 100uf)? There seems to be no physical size restrictions.