Mitsubishi 65907 Problem

[tbradsh1]

I have a Mitsubishi Diamond Series 65907 HDTV that quit this week! We were watching it and suddenly it went blank. I had a service company come out and they told me it was not repairable! He said that oil had leaked on the mother board and 2 of the guns....siad this was common with rear projection TVs. He said I would need to replace 2 of the guns and the mother board but the mother board was no longer available for this TV. He took my $59.95 and was gone.

Does anyone know if this sounds right? I am thinking of calling another service company but I would rather ask here before I do that.

Any help would be greatly appreciated!

[d6500k]

The "oil" is the coolant (ethylene glycol) that has seeped from its containment to the internals of your display. While not a common occurance, it does happen.

The irreplacability of the components ruined by the coolant is an issue. Icallo, a tech from Florida and a wizard with mits may be able to help.

Doug k

[tbradsh1]

When the technician was here, he said the oil was corrosive and you could not "clean" the board of the oil, is this true?

How can I get in touch with Icallo?

I appreciate your help!
Tony

[Ratman]

"lcaillo" is a forum member. He will probably pop in and provide advice shortly. If not, you can always send a PM and ask that he take a look at your thread and provide insight.

http://www.hdtvoice.com/voice/member.php?find=lastposter&f=12

[lcaillo]

This is not uncommon in these sets and the servicer is just following Mitsubishis recommendation for repair. This would be fine if the parts were available and if the cost (when they were available) was not prohibitive.

These sets are rather easy to fix, albeit tedious, if one follows a few guidelines. First, the areas with coolant need to be mapped carefully BEFORE the boards are cleaned. Second, the boards need to be cleaned thoroughly. Yes, you can clean them. The best way is to soak in isopropanol or denatured alcohol, or run them through a dishwasher. Then any corrosion needs to be repaired and any bad components replaced. Rarely are there bad components. Then every feed through on the double sided board needs to be checked for continuity in the area of the spill. The electrolytic caps on the regulators need to be checked just as routine service as they often are aging out in these sets at this age.

If the leak is not continuing, there is no need to do anything with the CRTs other than install a gutter to divert any residual drippage. If they are continuing to leak, they need to be dissassembled, cleaned, sealed with a very thin layer of RTV on the gaskets, and fresh coolant added after thorough curing of the sealant.

Most of these boards are not damaged beyond repair. I have fixed dozens and only two have been unrepairable. That was due to the coolant staying on the board for a long time. The coolant is a mix of 70% ethylene glycol and 30% glycerine. The glycol is not itself corrosive but is a very good solvent and absorbs moisture form the air and develops a very corrosive solution with time. It also migrates very well. It is easily cleaned , however, even with soap and water.

[tbradsh1]

Thanks for the info! I spent some time this morning taking the back of the set and giving it a good look over. No question that the Red and Green CRTs have leaked. Also the Brown, Red, Orange and Yellow wires that connect to the Red CRT are burned almost completely through, obviously they were shorted somehow.

The TV won't turn on now at all....the power comes on but absolutely no picture of any kind. I found where the technician that was here disconnected a set of wires on the mother board but that didn't help get any kind of picture out of it.

What do you think....should I junk it and start looking for a projector? This TV is in my theater room that is 21' x 21' and maybe I should cut my losses and re-do the room.

I really appreciate all the help, let me know if you think I should call someone else to have it fixed or if it is really cost prohibitive.

Thanks!
Tony

[lcaillo]

Can't say. I would try to find a tech who will do an actuall assessent of what is wrong and give you an estimate. This could be costly, as there is no way to troubleshoot it without cleaning the boards first. The tech should have never tried to fire it up at all if there was coolant on the boards. Did he detail what he found or just jumped to the conclusion that you needed tubes and a board?

[tbradsh1]

When he arrived I powered up the tv and he powered it down. He opened the small front cover and looked inside with a flashlight. He saw the oil and the burnt wires and told me the tv was probably not repairable since there were no motherboards available. He was only here for 10 minutes. If it's going to be costly then I might opt to replace it since it's almost 7 years old.

[Ratman]

Just to pop in and say, "thank you"!

Excellent assistance and explanation, lcaillo! :)

[lcaillo]

Actually, the baords are available in a manner of speaking. Mits now has a repair and return rebuilding program for them. I doubt seriously that a decent tech couldn't fix the set without sending a bourd back, but it depends on how badly things got cooked.

If you wanted to bring the light box over to gainesville our standard estimate is $50, which applies to the repair if done. And it would be a real estimate. You would have to align the convergence when you put the light box back in.

You are welcome, ratman.

[Jen_Kenne]

In reference to post #5:

This is what happend to my 65907. The question is whether I hire the repair, or attempt it my self. I lean toward the former, since I don't have time for yet another project.

[lcaillo]

Only use a tech that has a lot of experience with these, and follows the suggestions that I made. If you don't, there will be a lot of tail chasing in many cases, and lots of them never get fixed.

See some additional discussion here:

http://www.hometheatershack.com/forums/service-support/8019-crt-based-rptv-coolant-problems.html#post67460

[Jen_Kenne]

Thanks for the information. I have a Tech with the experience to make these repairs and guarantee his work, so I feel good about having it repaired. He also plan to put in a tray to protect the system against any possible future drips. A pity that Mitsubishi did not do this with the 65907 - it would have eliminated the corrosion damage.

[Jen_Kenne]

Turns out there was more than one problem. No audio or video. The leak caused some corrosion on the board, which was repaired by my Tech. The cooland seals were repaired, and the entire system tested. The WS65907 does not have a 'drip tray,' so one was fabricated. In addition, a power surge had blown out another board - parts were available, thank goodness. It's back and as good -- if not better -- than new. I don't know what the product life or MTBF is for these units, but I hope there is another five years in the unit, until I build up my front projection system.