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-   -   "Blinking Green Light of Death" - a frequent prob. w/Mitsubishi rear-proj widescreens (https://www.highdefforum.com/rear-projection-tvs/58189-blinking-green-light-death-frequent-prob-w-mitsubishi-rear-proj-widescreens.html)

Paul D318 12-07-2007 08:39 AM

"Blinking Green Light of Death" - a frequent prob. w/Mitsubishi rear-proj widescreens
 
Thought you folks might get a kick out of hearing how I managed to fix my broken TV this past weekend, and might want to have this info if/when your Mitsubishi rear-projection TV suffers the same "death".

My Mitsubishi WS-55613 (55" rear-projection HDTV) died Saturday, just when I tried to turn on the UNC/Kentucky game. It was exhibiting what I'd seen described before (found at another online HDTV forum) as what appears to be a very frequent problem that occurs in Mitsubishi rear-projection widescreen HDTV's, referred to as "The Blinking Green light of Death". This refers to the green LED on the front panel of the TV that normally blinks when turned on after a power failure or when unplugged: the green light is supposed to flash for about 1 minute while both microprocessors boot up: If it won't stop blinking it means that they aren't communicating w/each other, and you ain't got no TV to watch... :(

About a year ago, I'd noticed and saved an article describing this issue, along with a repair procedure to replace the four (apparently inadequate) 1000uF/16 volt power supply capacitors in the "DM module" (one of the two onboard microprocessors). These capacitors are apparently undersized, in that they will eventually fail (usually after about 3 years) if and inevitably when there are voltage fluctuations in the circuit above 16 volts. (If you Google: "Mitsubishi + Blinking Green Light of Death", it's amazing how many other Mitsubishi rear-projection TV owners have experienced this problem.) It is recommended to install either 1000uF/25 volt or 1000uF/35 volt capacitors as replacements, so that they will be more than ample to handle any voltage spikes that will occur.

Since I have little/no experience repairing printed circuit boards, I was a bit intimidated to try this on my own, but was motivated by the one person at that forum that said he'd had to pay $600+ for the replacement DM module his set needed, along with about $150 for installation.

I went online to another HDTV forum and this time found two similar "fix" articles describing the same problem and correction, and one of these articles came complete with photos depicting the repair procedure. This led me to believe that this might actually a legit repair, as others had posted that they'd successfully repaired their TV's w/this procedure. On Sat. night I went to Radio Shack, bought the (4) 1000uF/35 volt capacitors recommended as replacements (they were out of the 1000uF/25 volt caps), and after taking the back of the TV apart and removing the faulty DM module, got my girlfriend Rene to help hold the DM module's printed circuit board while I desoldered the old capacitors and installed the new ones. (She was a remarkably patient assistant, I might add...)

Much to my dismay, after getting the TV put back together enough (I thought) to test it at about 12:30 a.m. Sunday, it would still not work, and exhibited the same "Blinking Green Light of Death". I went to bed VERY disappointed... :crying:

Sunday morning, I set about taking it BACK apart, to see if I'd done something wrong or left something disconnected. I then realized that since I'd not installed the back cover plate for the DM module, which has (apparently critical!) grounding straps essential to the proper functioning of the DM module - the DM was not getting proper grounding. :error My brother, (who is an electronics tech for a local LED lighting manufacturer) came over before I reassembled the TV and also found a couple of "solder bridges" on a couple of the DM's printed circuit board components (sloppy soldering), which he feels might have also contibuted to the failure of the original power supply capacitors. I put it all back together again, plugged it in, and it fired right up! :banana:

After an investment of $6.79 for parts, 3 beers for my brother David, and about six hours of my time - it is SO rewarding to watch TV on a set that I fixed myself! It is amazing what kind of information you can find on the internet...

I get a kick outta this kinda stuff - but I am admittedly easily amused... ;-)

Here is the link for the instructions I used:

http://www.fixya.com/howto/h159332-m...m_board_repair

Note #1: My buddy repairs HDTV's for a large national electonics chain store. His opinion is that the cooling fan recommended in this article is unneccesary if you replace the failed capacitors with caps that have a higher voltage rating: heat is not what is causing them to fail, it's the voltage surges that occur in the circuit they serve.

Note #2: Some of the larger Mitsu widescreens use 7 capacitors in the DM module instead of just four, but the issue and repair procedure is the same.

I hope this info helps - Paul

PS: Contact me if you have problems with the link or want me to email you the .pdf file with the repair procedure described.

edders 12-07-2007 10:52 AM

Great post
 
First off, I would not recommend that most people try repairing electronic items. You however seem to have done your homework and had adequate help and advice, so it is great that you saved your Mitsi.

So you bought your bro a few beers, did you buy your girlfriend flowers?
:eek:

Ed

truedamen 12-07-2007 12:18 PM

Well Done!!!!
 
I also had the dreaded "Blinking Green Light of Death" on My Mits WD-52631. The culprit was a thermister that's in close proximity to those same caps! I am an Electronics Technician(and specialize in micro-electronics) for the government so I am more than qualified to unsolder ANY component.
The set was under warranty so I called the local repair rep to come and fix the problem-LET MITS FIX IT! I had to wait 5 days for the repairman to come out which pissed me off. Once he arrived I told told him what the problem was and the possible causes("Blinking Green Light ","blocked airflow" ). He had NO idea what I was talking about so I took off the back cover and low and behold toasted thermister!
If your set is under warranty I recommend using their resources primarily for safety reasons. However, Google can be your best friend if your set is out of warranty and brave enough to fix it yourself because I was pointed to numerous people at various forums with the same problem.

Paul D318 12-07-2007 01:07 PM

JustEd:

I didn't buy her any flowers, no. I have repaired numerous things at her townhouse, and am also called upon whenever she needs anything larger than a toaster oven transported (since I have an '02 Silverado pickup), so she's still on the plus side. (I did give her more than a couple of big kisses during the process, however...) :D

Trudamen:

I certainly would have gotten it fixed under warranty - if I'd had any warranty left (I AM crazy - but not stupid! :D ) but I am two years out of warranty. I do have a friend that repairs big-screen TV's for a living, but he's been sick (with repair jobs backlogged) and I didn't want to wait 2 - 3 weeks for him to get over to my house. I bounced this repair job off him (after the fact) and he said that using the higher-voltage capacitors was definitely the right thing to do.

Also - what does the thermistor you described look like - and how do you test it?

Another question (since you're an electronic tech) - Do you use a desoldering tool when doing such pcb work? I've gotten differing opinions, but it seems that it would be a good idea...

Thanks - Paul

PS: Thanks for the pats on the back, guys. I'm just hoping to help anybody else that has a widescreen Mitsubishi w/this same problem (and some basic soldering skills) so that they can tackle and resolve this problem as I did.

It was actually a lot easier than I thought it would be!

truedamen 12-07-2007 02:31 PM

First of all your impatience led to ingenuity-RIGHT ON!!!
-Secondly, a thermister is a thermal sensor that monitors airflow to the lamp(DLP). Once the set was opened it looked like partially charred two lead flat transistor that was reading open(using a fluke 87 multimeter). The part that replaced it looked like a piece of wire with a thin film of ceramic around it (I also tested it and it read short).
-Third, I have a portable PACE soldering station that is for personal/home use but a very effective an inexpensive way to remove solder would be to use a soldering iron and solder wick that you can easily obtain from any Radio Shack;Try it -it works!

Paul D318 12-07-2007 08:28 PM

Quote:

Originally Posted by truedamen (Post 440556)

I have a portable PACE soldering station that is for personal/home use but a very effective an inexpensive way to remove solder would be to use a soldering iron and solder wick that you can easily obtain from any Radio Shack;Try it -it works!

1) You've apparently got a really nice Mitsu WD-52631 DLP, whereas I've got a rear-proj CRT set with no lamp fan, etc. I guess this means that at least I don't have a thermistor to worry about? :what: I've got enough grey hair... :eek:

2) What do they get for one of those Pace soldering stations - and where can you buy one?

Thanks - Paul

truedamen 12-07-2007 08:44 PM

I am not sure of an actual price;my solder station was acquired through my job but this website may be useful to you www.paceworldwide.com

smarter3 12-08-2007 02:15 PM

please help me I have this same problem.

Quote:

Originally Posted by truedamen (Post 440356)
I also had the dreaded "Blinking Green Light of Death" on My Mits WD-52631. The culprit was a thermister that's in close proximity to those same caps! I am an Electronics Technician(and specialize in micro-electronics) for the government so I am more than qualified to unsolder ANY component.
The set was under warranty so I called the local repair rep to come and fix the problem-LET MITS FIX IT! I had to wait 5 days for the repairman to come out which pissed me off. Once he arrived I told told him what the problem was and the possible causes("Blinking Green Light ","blocked airflow" ). He had NO idea what I was talking about so I took off the back cover and low and behold toasted thermister!
If your set is under warranty I recommend using their resources primarily for safety reasons. However, Google can be your best friend if your set is out of warranty and brave enough to fix it yourself because I was pointed to numerous people at various forums with the same problem.


truedamen 12-08-2007 03:38 PM

Known Defect
 
This is a common problem on the WD series. The company knows about this defect. If your set is under warranty spare yourself the continuous resets and have it serviced, the fix is unbelievably easy. If not Google "Mitsubishi Blocked Airflow Message" and you will be amazed at the hits. From there I can tell you the tools you will need to unsolder two points.

BANDB 12-08-2007 04:10 PM

Quote:

Originally Posted by truedamen (Post 441900)
This is a common problem on the WD series. The company knows about this defect. If your set is under warranty spare yourself the continuous resets and have it serviced, the fix is unbelievably easy. If not Google "Mitsubishi Blocked Airflow Message" and you will be amazed at the hits. From there I can tell you the tools you will need to unsolder two points.

I just got a letter from Mitsubishi stating that this particular issue is being warranted for two years beyond the original 1 year factory warranty.

truedamen 12-08-2007 05:22 PM

Although Mits customer service is not known to be good it is refreshing to see that they are willing to correct their mistake.

Paul D318 12-08-2007 05:36 PM

Smarter3:

I got all all scubbed up and ready to help you. And then I realized that we're gonna need to have a little more info in order to help you out.

Like, what is the model # of your Mitsu that we are working on, bro? Rear projection CRT - or DLP - or what? And how old is it? :helpme

It's also possible you might get some help from Mitsubishi if you're not too far out of warranty (as described by BANDB).

Different models have slightly different features. As described above, trudamen has a Mitsu DLP with thermistors next to the caps that failed. Some Mitsus have 7 caps instead of just 4. And so on...

Get us the info and we may well be able to help you fix your set...

moparelvis 01-02-2008 12:06 PM

Hi, I have a WD-52631...my green light never stops flashing. I had a tech come out and try to get a code...but again the green light never stops flashing...even if I leave the tv on for hours.
He believes its the power supply board and wants to charge me $400.
My question is...could this issue be the thermistor??? Every where I have read people see the over heating warning...they can at least have the tv on for 10 seconds.

I never am able to have the tv on and never get a warning...
so...
1. thermisotr
2. dm board
3. power supply board

which one is it???

Paul D318 01-02-2008 12:40 PM

Quote:

Originally Posted by BANDB (Post 441937)
I just got a letter from Mitsubishi stating that this particular issue is being warranted for two years beyond the original 1 year factory warranty.

Have you tried calling Mitsubishi Customer Service? According to Trudamen's post (3rd post in this thread - above) they have extended coverage for the WD series of sets that are having this problem. (Hint: When you call them, be NICE! Be the person that they want to help!)

You might also want to PM him and see if he can give you any add'l info on replacing the thermistor yourself (it ain't brain surgery...). I'd also replace the caps while you're working on the DM board. If you do this, don't replace them w/identical capacitors. The 1000uf/16v caps they installed at the factory fail because due to voltage spikes in the circuit occasionally exceed 16 volts: You need to step up to 1000uF/25 volt or 1000uF/35 volt capacitors that can handle the inevitable spikes. I installed 1000uf/35v caps and mine is working great. :yippee:

But - try calling Mitsu. Customer Svc. first. PM me if you don't have any luck w/them and we can try to get you going for less than $400.

hdgtx 01-02-2008 08:54 PM

Which models of Mits RP's are you guys talking about ?
Is this problem happening with the current 733, 734, 831 & 833 series RP's ?


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