Mitsubishi WD-65735 ballast no-power situation.

Yep, it finally happened. The Mitsu 65" is dead, and I might be in for a rather hefty parts bill unless someone has a better idea.

Just put a third bulb in the set, I've had it for 5 years. It's on most of the day, so that's why I went through so many bulbs. Only 2 weeks after new bulb #3 went in, I come home from work and the wife says TV is broke. Sure enough, no light out the back. I figure the new bulb went out, but it's fine. Troubleshot it down to some sort of issue with the main board underneath the power supply.

Here's what I have so far:

There is a pin labeled 'lamp relay' on the power supply board, which receives around 3 volts DC from the main board when the lamp is (supposed to be) on. 3 volts goes to a discrete transistor driver circuit, which then activates the relays for the lamp ballast. It's the same exact circuit for mains input, only mains has a single relay. So I make the assumption that the ballast is not being told to turn on, and jumper 'main relay' to 'lamp relay' on the power supply. Kills the whole set, there's a short somewhere in the lamp circuit so that any time I jumper it the mains relay goes open. I removed the lamp relay wire from its connector on the power supply side and tried again, light comes on no problem when I jumper it. I assume this means the main board is bad ($400, f that), or it thinks there is a fault in the lamp so it is off for a reason...

I don't feel safe leaving it jumpered, because if there is an overheat condition I could be setting myself up for a fire. So what's my best shot at fixing this, besides the uber expensive main board replacement? Should I try a ballast board first, on the off chance the fault lies there?

Does the led flash any codes? That will get you closer to the issue. May take several tries, but a code will eventually show up. I can get the parts for very little here. let me know what you need and I'll be more than happy to send them your way. BTW, those are pretty decent TV's and pretty simple to repair/disassemble. Have one at my shop for sale and I just repaired a customers(DLP chip)

Any chance you could post me a main board and a ballast for troubleshooting purposes? If either of them ends up fixing the problem, I'll pay and send what I don't use back.

No codes, because the green timer light never stops flashing. Yes, they are very nice sets and make a great quality picture. That's why I'd like to keep it, it's given me good service till now so I can't see dumping it for it's first offense. :smoke:

Any chance you could post me a main board and a ballast for troubleshooting purposes? If either of them ends up fixing the problem, I'll pay and send what I don't use back.

Stupid double posting work computers!

I'd try to fix that Mitsu. I just googled Mitsubishi, and found out that they are now out of the rear projection TV business for good. Not only that, but RPTV itself is a dead technology, having been upstaged by today's flat-panel LCD and plasma televisions.

If your RPTV cannot be repaired, I would say replace it with a similar size modern LCD or plasma set and don't look back. Unless you have some special reason for wanting to keep the Mitsu RPTV, you would probably, IMO, be better off with a modern flat screen. Just a thought.

Why this set? Because the image quality is as good as an LCD (if not better than some) plus you could not approach the price with a 64 inch LCD at the time.

The discussion makes me wince, though. Mine is used only about an hour a day, so maybe that's all that's keeping me from the same failure point.

I don't understand LCD's pushing these out of the market, it seems a poor judgment to me to insist on something thinner at a higher price. The depth is not that great, and you can't put anything else on that side of the room anyway whether you have something thinner or not. It's not at all like the old CRT rear projos that really ate up floor space.

Wayne,

It's these damn kids and their newfangled thin tubeless sets, and cars with wheels that are too big- you wouldn't understand. :D

You're right of course, there was no way to touch a 65" flat panel for anywhere close to what I paid for this. Plus the picture quality is very good on this set, I hate trashing anything that works as god as this one does (did). If mstaton can get the boards for it I'll give it a go, if not it may not be economically viable to repair. In that case I may have to store it till a donor set pops up on CL.

Why this set? Because the image quality is as good as an LCD (if not better than some) plus you could not approach the price with a 64 inch LCD at the time.

The discussion makes me wince, though. Mine is used only about an hour a day, so maybe that's all that's keeping me from the same failure point.

I don't understand LCD's pushing these out of the market, it seems a poor judgment to me to insist on something thinner at a higher price. The depth is not that great, and you can't put anything else on that side of the room anyway whether you have something thinner or not. It's not at all like the old CRT rear projos that really ate up floor space.

I think the problem, if you want to call it that, is that RPTVs use (by 21st century standards) outdated technology, and today's TV makers don't want to use 25-year-old tech when modern flat screens use less power and take up less room than the older sets did. Don't forget, a large-screen RPTV set can draw up to 500 watts, depending on brightness, etc. settings. Years ago, large-screen console b&w tube TVs were notorious for being power hogs, some sets drawing 300+ watts in normal operation.

Early RPTVs may have been as large as you say, but I've seen pictures of sets, such as Zenith's Space Screen 45 (I saw an old ad for one on Youtube recently), that take up no more space in an average-sized living room than a traditional 25" CRT console TV -- and with the SS45, the screen disappeared into the cabinet when the set was turned off. This may have been a selling point for the SS45s, but the mechanism that raised and lowered the screen would fail after a period of time. The screens were fixed permanently in the up (viewing) position and the drive motors unplugged when the drive system failed. No more disappearing screen, but at least the TV still worked, and many such sets were kept and used until they developed more serious problems, causing the owner to junk them.

PM your address and I'll get them out next week

modern flat screens use less power and take up less room than the older sets did. Don't forget, a large-screen RPTV set can draw up to 500 watts, depending on brightness, etc. settings. Years ago, large-screen console b&w tube TVs were notorious for being power hogs, some sets drawing 300+ watts in normal operation.


Apparently you haven't read any labels lately, my folks have a 46" plasma that draws over 400 watts from the outlet. My 65" DLP draws about the same, but with a much larger picture. My CTC-4 draws under 400...

Of course, for the price you paid then (if you bought it new at a regular store) plus the three bulbs, you could definitely get a 65-inch flat-panel set today. That is why rear-projection sets have now gone away, the price advantage is not there anymore, though they were certainly a good value for many years.

It's pointless stating what one 'could' have done, it's not like I was going to sit there without TV for 5 years while saving the money I wasn't spending on bulbs for a better unit. :D Besides, some of the flat panels have pretty horrible track records too. How many times this year am I going to hear about another y-sus board going out, or a power supply getting taken out by a bulging capacitor? My Mitsu had no bad caps on it, all the important ones were actually Nichicons which surprised me a little.


I have an update:

I actually did the shameful thing, and called the TV repair guy. Yeah yeah, I know. For $50 they stuck it on their bench, and confirmed what I already knew: the main board is toast, but interestingly it seems to have been caused by the DMD board shorting out so I need both. Mitsu say they have both parts available, $300 for the main board and DMD for around $100. I'm hoping the repair place tells me the same, so this can be resolved for around $500. The 50 I paid to have it picked up applies to the final bill as well, so hopefully this will be resolved soon without a lot of bitching about money. They were surprised I actually wanted it fixed, but it's been a good runner for me and I can't see giving it up if I can get 5 more years out of it. How many flat screens are still around after 10 years?

Sorry miniman, all my sources did not come up with any parts. They said that they are hard to find that work. :(

None of the internet places had any either (shop jimmy, ect), but Mitsu claim they are in stock. Probably a lot of warranty work being done on these. What's interesting is mine didn't fail in the same way I usually read about, most people are complaining of 'dots' or 'measles'. I had no such defect. In fact the DLP chip in mine looked brand new after I dusted it off, no haze or halo or anything. I think it's just a case of overheated parts to be honest, the fans in this set don't move near enough air to keep it cool. So when I get it back, the first thing I'll do is take the fan off my CTC-4 and put it on the DLP set. Color wheels, cooling fans.... something all too familiar about all of this. :yes:

Nonstop flashing timer LED is the DM computer not booting up. Ordinarily when these sets are first plugged in, that LED will flash for about 60 seconds while the computer boots, then stop which means the set is ready.

It's bad caps. You'll see the bulgies if you take apart the DM, but there are plenty more that will need to be changed for this to work. Some models are lousy with surface mount caps, not a task for the faint of heart!

Must small SMD caps then, because none of the regular cans were bulging/leaky.

2 months later, and I finally got my set back. I can't say I would recommend the repair place I went to, but they did do the job for the price they quoted me. Now to get used to my regular sized tv, the temp one was only a 36"....

Hey Nick, glad you got it fixed. You were telling me about that nightmare at the ETF, at least it has a good end, unlike anytime I've ever taken a tv to a shop....
I remember seeing that set in action after a new bulb, the picture was outstanding, worth the effort you put in, that's for sure:yes:

Trade ye for a superfine 16x9 trini? muhahaha!

I have a WD-65735. A year or so ago it was hit with lightening. I took it to a repair shop and they could not pinpoint the problem. They suggested replacing the main board. I will dig the tv out of storage and plug it in to see what all it is doing as I do not remember.

I have uploaded 4 pics. They are the front and back of the power supply board and the main board. I plugged in the TV and there were no blinking lights on the front panel. The tv made no sounds and no light came on in the back of the tv. I noticed the glass fuse on the power supply board had 4 color stripes on it. They are tan, black, orange and yellow.

If this set was indeed a lightning victim...then the first thing you need to do is see if you are getting any standby voltages off of that power supply board.

With the power cord plugged into it (and the board out of the set for convenience)--do you see any sort of voltage on that 12 volt line on the power supply ? Since your set appears to use the SMPS all of the time for power even in standby --there definitely MUST be some voltages from it even when the tv is not on --but plugged in. Likely a 12 volt line, maybe a 5 volt line, maybe that 21 volt line. All are referenced to cold ground. near the middle of the supply picture--there are 2 capacitors. Above them is a heat sink. Is there any appreciable voltage on these caps? There should be in standby.

If you get NO standby voltages--then the switcher control chip has likely been taken out. Can't tell for sure--but looks to be the part on the other big sink--below the "live" symbol, and above the 820 uf cap.

You have the Green light of death. Power supply and or many bad electrolytic caps. Good luck. It's the V26 Chassis. Not very repairable. I had a VK26 and gave it to my kid. Much less problems. The flashing is coming up because it will not boot up the Micro. Also could be an Eeprom problem too. good luck

I have the WD-60737, new in 2010. At about 6 months you could turn it on, the green light would flash a while and it turned off.

There was a firmware update, downloaded it from Mitsu and fixed the problem! It still works like new to this day!

FWIW, I checked the odometer on it and has over 16,000 hours, and the lamp has been replaced twice.

Mention was made several times about rear projection TV being an obsolete technology, well perhaps the rear-projection part, but certainly not the DLP technology used to generate the picture, which is used in all movie theaters, and in all video projectors (well most all). It is quite current, and not obsolete.

Rear projection with CRT's is obsolete, rear projection with DLP is debatable considering the wide range of flat panels available today. What will differ is the price you pay per sq inch.

Rear projection with CRT's is obsolete, rear projection with DLP is debatable considering the wide range of flat panels available today. What will differ is the price you pay per sq inch.


You are absolutely correct. RPTVs using CRTs are obsolete these days, and it isn't worth having one of these sets repaired anymore. It's better to junk the old RPTV and buy a new flat screen, as the latter have come down in price and continue to do so, considering that UHD and 4K are beginning to catch on. H. H. Gregg and other places now have 32" HDTV flat screens for under $200, so, again, it is hardly worth it to have an old, obsolete RPTV repaired.

It makes even more sense to get a modern HD flat screen to replace an older set when you consider that today's FS TVs deliver much better picture quality than the RPTVs ever did. I remember reading somewhere that, while rear-projection CRT TVs were good for what they were in their day, nowadays modern FS sets will run rings around them.

I cannot imagine why anyone would want to put hundreds of dollars into repairing a 32-year-old RPTV when the person could get a modern 32-inch or larger flat screen for the same money, or even less. RPTVs like Zenith's Space Screen 45 were good for what they were, given the state of the art at the time (early 1980s), as I mentioned, even though their advertisements for them (there is one on YouTube) would have one believe that these sets were the greatest thing to come along since color TV itself.

However, I think the disappearing screen was the SS45's real selling point. Zenith, in the ad I mentioned, stated "By remote control, the screen rises from the fine furniture cabinet. . . . Space Screen 45. More than three times the area of a 25-inch screen, yet the picture is sharper than ever before in home projection TV. And only Zenith has a screen that disappears. . . . Only Zenith has it."

In 1983, when Zenith meant Zenith and their TVs were still made here, the claim that the sets made the best picture possible in home RPTV may have been true, but today, that set could not hold a candle to any modern HDTV flat screen. That is, RPTVs were the first attempt at very large screen TV, with the SS45 being one of the first if not the first sets to use the then-new technology. It was the best the industry could offer to the public at the time, but as time went on better things (such as DLP and later LCD flat screens) came along, rendering CRT-based RPTVs obsolete.

As with any new technology, these then-new RPTVs had problems. Zenith's Space Screen 45 may have had a good picture for its time, but the motorized drive mechanism that raised and lowered the screen would fail after about a year or so of use, depending on how much the set was used. Some set owners got around this by fixing the screen in the viewing position and unplugging the drive motor, continuing to use the TV until it developed more serious problems.

The SS45 was sold for only one or two model years, probably due to the problems with the motor drive. In homes with no small children, the drive mechanism in these sets might have lasted somewhat longer than a year, but in homes with kids who became fascinated with the disappearing screen (they would constantly push the button on the remote to see the screen go up and down, probably when their parents weren't looking), the drive may have failed quite a bit sooner, due to worn-out gears and even burned-out drive motors (those motors were not meant to run for any extended length of time).

DLP is certainly not obsolete technology, although its use in rear screen sets is now made obsolete by Flat Screen tv's. DLP is as current as any technology for video projection. I can understand that a high-end rear projection DLP could deliver as good a picture as many LCD.

DLP is certainly not obsolete technology, although its use in rear screen sets is now made obsolete by Flat Screen tv's. DLP is as current as any technology for video projection. I can understand that a high-end rear projection DLP could deliver as good a picture as many LCD.

DLP may not be obsolete (today's motion-picture theaters use this technology instead of old 8- and 16-mm projectors), but miniman82's and my point is that projection televisions using cathode-ray tubes are indeed obsolete, much as the NTSC television standard was rendered obsolete by the ATSC one in 2009.

Advances in technology since the early 1980s may well have resulted in DLP sets that can deliver pictures as good as today's LCD sets, but the size of most DLP TVs may be keeping them out of American living rooms, not to mention the short life of the projection lamp. I don't know whether today's DLPs still use arc lamps, but if they do, set owners still must replace that lamp every so often, depending on how much the set is used (often at considerable expense; I understand these lamps sell for something like $100 apiece if not more). It may very well be that today's DLP TVs use high-power LEDs as backlight sources, which all but eliminates the chance of a bulb burning out; most LEDs can last hundreds or thousands of hours to half brightness, not unlike LCD television screens. The latter are often rated for 60,000 hours, which works out to 20 years or more of average use. Too bad the electronics in LCD flat screens, more often than not, fail after only four or five years, :no: while the panel still has plenty of life left in it.

DLP is certainly not obsolete technology, although its use in rear screen sets is now made obsolete by Flat Screen tv's. DLP is as current as any technology for video projection. I can understand that a high-end rear projection DLP could deliver as good a picture as many LCD.

Do the DLPs in RPTVs and large projectors have life issues?
A few years ago, I bought a small Pico projector that uses DLP technology and LED lighting... within a year, many pixels had failed... today, the picture looks as if the scene was shot in a blizzard. The projector ran quite warm (even on low brightness setting) so I'm guessing that the failure was temperature related. A larger unit also failed. Expensive little short-lived toys! :thumbsdn:

jr

Add: link to old post on Pico Projector(s)
http://www.videokarma.org/showpost.php?p=3099076&postcount=2

I have a full 1080p Optima DLP projector I have mounted on my ceiling. It has performed flawlessly for 1.5 years so far, on the original bulb, no failing pixels, and the image looks good, like a true film on my white screen. DLP is current technology that is constantly improving. In a previous comment, someone said that movie theaters now use DLP instead of 8mm and 16mm film....well theaters NEVER used 8mm, and only a few venues ever used 16mm. 99% of theaters used 35mm film, and big venues used 70mm film with 6 track magnetic sound. DLP is just about as good (in theaters) as film, and is often better because there is no way for an untrained popcorn jockey to set something (on a film) up wrong. I think people just got tired of the depth of rear projector sets, and changing a bulb for a relatively high price once in a while. There were built (and the Mitsubishi under discussion may be one of them) DLP rear-projection TV's that could display 1080i (if not 1080p), and in fact I have a Mitsubishi rear-projection CRT projector that has HDMI input and easily displays 1080i, so rear projection is not so obsolete for viewing current TV standards.