Dim Mitsubishi WD-73738 DLP Telivision

[Spork Schivago]

Hello!

I have a 73" 3D Mitsubish WD-73738 DLP television. The lamp inside of it was some very cheap replacement. The housing for the lamp had been modified for this very cheap replacement bulb. I went to ShopJimmy and ordered a new lamp housing with a Philips bulb. I believe this was the brightest out of all the three options.

The TV itself was horribly dusty. I tore it apart and cleaned everything, very careful like. I removed the ballast and cleaned all the dust off of it, I removed the main board, the power supply, cleaned all the dust off of it. I removed the Optical Engine, tore it apart very careful like, removed all the dust.

I removed the three fans on the optical engine, cleaned them really well. I even tore apart the screen itself and cleaned in there. Cleaned the mirror, etc.

I put it back together, with the new bulb, and much to my surprise, it's still dim. I do not have the remote, so I cannot access the service menu, although I am going to try programming a Spectrum "universal" remote to see if I can see anything wrong. A factory reset was done after the new lamp was installed, but before the TV was turned on. I thought maybe brightness was turned way down low and I will check.

Assuming the brightness levels are okay, any ideas what might be wrong and how to test? Internet suggests optical engine, perhaps the colour wheel. But the colour wheel doesn't make any weird noises and the colours look good, just very very dim.

Thanks!

[R_J]

Re: Dim Mitsubishi WD-73738 DLP Telivision

The color wheel won't effect the brightness, there is likely something in the light path that is bad, There should be a uv filter near the lamp/color wheel, it could be discolored due to heat, or the lens itself could have dust inside it or discolored if was from a smokers house

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

Thanks R_J. I mean if there is dust on the colour wheel, would that affect brightness? I realize if the colour wheel itself is bad, that wouldn't affect brightness. I have cleaned all the dust off the entire TV, inside and out, cleaned all the glass windows, the mirror, etc. I did not open up where the colour wheel itself was, so there could be dust inside.

I just got a universal remote that finally allowed me to access the service menu and looking at the log, I see error 0066 for the current time (30700 hours). What's nice about the log, it shows a time, but also shows the total run time (I'm assum,ing 30,700 hours is the run time). And there's a big cap from the previous errors (such as the bad ballast one) and the 0061's. The 0061's are all new errors that have occured since I have had the TV...

Here is a copy of the service manual. It does not list a 0061 error code, however, Google suggests something with the colour wheel.

After the TV has been on for a bit, the brightness does appear much more brighter...

Finally, some other issues I've noticed. HDMI input 3, if you plug a cable in, it doesn't register sometimes. You have to gentle pull up on the cable. I think perhaps it needs to be reflowed. And more annoyingly, sometimes, the on screen display goes nuts when you hit a button. Almost like a button is stuck, but it isn't. Power cycling the TV is the only way I've found to fix it.

[R_J]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I doubt the color wheel will collect dust, but be carefull if you clean it, it is very fragile. There are other lenses etc in the light path that can get dirty, you would need to open the light engine and inspect the lenses. Some light engines have a UV filter near the color wheel that my get discolored over time. A sticking button is posible, those tac switches do go bad and cause all kinds of problems.
make sure the lamp is mounted properly in the housing, if it's not pointing straight you will loose light output.
when you cleaned the fans were they very dirty and diid it smell of nicotine?
The error: 61 No LAMP-EN output from the engine to the ballast, Bad Color Wheel (Loose J6 or J7 connector)
I'm not sure if this is your exact light engine but you can see what could be inside.

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I doubt the color wheel will collect dust, but be carefull if you clean it, it is very fragile. There are other lenses etc in the light path that can get dirty, you would need to open the light engine and inspect the lenses. Some light engines have a UV filter near the color wheel that my get discolored over time. A sticking button is posible, those tac switches do go bad and cause all kinds of problems.
make sure the lamp is mounted properly in the housing, if it's not pointing straight you will loose light output.
when you cleaned the fans were they very dirty and diid it smell of nicotine?
The error: 61 No LAMP-EN output from the engine to the ballast, Bad Color Wheel (Loose J6 or J7 connector)
I'm not sure if this is your exact light engine but you can see what could be inside.

If you doubt the colour wheel will collect dust, then I will not clean it. I have cleaned all other lenses in the light path. I opened the optical engine and cleaned everything. I have tested those tac buttons as best I could and none seem to actually stick. I would think if it was a stuck button, unplugging the TV and plugging it back in would not fix the issue. I took a DMM and measured continuity while pushing them (while the PCB was removed and unhooked). Granted, there is a good amount of bounce, enough where the DMM could read it!!! None seemed sticky and all seemed to work.

The lamp housing can only go in one way. And because the old housing was modified in a bad way by the previous owner, I replaced the entire housing and lamp. It came preassembled from ShopJimmy, so I believe the lamp and housing are fine.

I am thinking there is something else going on here.

There was dust all over the place. Even the heatsink that is above the DLP chip had it caked on. I did not smell any cigarette smoke though. The sirocco was very bad. I had to open it up to get to the fan blades and it took a very long time to clean. The fan on the DMD board or whatever you want to call it, that was bad as well. The exhaust fan was horrible. It's like the previous owners never cleaned it.

I removed everything and spent three days total cleaning the entire thing. I did NOT remove the heatsink for the DLP chip, I did not remove the colour wheel.

I was thinking that error might be the same, something with J6 / J7. I thought maybe I could first start by checking the voltage going to the ballast, and maybe the voltage leaving the ballast, but I do not know a lot about DLPs. I really appreciate you helping me try to figure this one out R_J.

There was actual dust inside the old light bulb. It was actually inside of it!!!! I have no idea how that old light bulb was still working, but it was working!

If it would help, I can take pictures of all the boards and tear apart the optical engine again and take pictures of that, so you can see how I cleaned it and maybe notice something I missed?

[R_J]

Re: Dim Mitsubishi WD-73738 DLP Telivision

Did you open the light engine and expose the lenses like in the picture I provided? on some light engines the have a actuator mirror, below the final lens, it can get dirty and is fairly easy to inspect

some of the dlp lamps are vented so dust can get inside the reflector

[budwich]

Re: Dim Mitsubishi WD-73738 DLP Telivision

How about this "story".... the first "replacement lamp" wasn't an OEM but a "third party" that may not have been the proper / "marginal" wattage for the system. It may have started OK... but during "lit operation" stressed the drive circuit of the ballast such that the circuit has a slightly higher "drive resistance" thus providing lower current. Your replacement (wattage??? ) may again still start but now the drive circuit is limited in output. Bulbs is always fun.... of course, as suggested earlier, check / clean the connector connects, check the voltages.... probably the initial "strike voltage" might be ok since the lamp is starting, probably the stability of the longer term voltage might be of interest.

what is your "lamp energy" setting?

elsewhere in the internet on a similar "dim lit after bulb replacement".... quote: "The light engine was replaced today. That was the ticket; 100% improvement. The repair guy acknowledged that it looked "great, even with the light on"!
Mitsubishi is covering all parts and labor. " It would appear that based on the "cleanliness" of the set, that perhaps this might be the likely point of contention.

[ajshoe]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I had one of these sets - free of course and repaired it. I used it for several years - great tv and good picture for the technology. My guess is you have tainted lens - filter in front of the light engine (behind bulb). The lens will need to be cleaned or maybe replaced.
There is also a mechanism in this set that shutters light (a mechanical arm that allows light or sheds light into the light engine.

the OSD appearing on the screen is a Mits software problem. I had this happening on my set and called customer service several times - there is no fix for this from my experience. If you had posted this 2 months ago - could have sent you a good light engine - Just recently threw all my old DLP parts in dumpster - I filled a 10 yard dumpster !

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

Did you open the light engine and expose the lenses like in the picture I provided? on some light engines the have a actuator mirror, below the final lens, it can get dirty and is fairly easy to inspect

some of the dlp lamps are vented so dust can get inside the reflector

I tore the entire light engine apart, minus where the colour wheel was. I will open it up and take pictures of it in a little bit. Thanks!

One thing my wife and I seem to remember, when the inputs are going wonky, there's never a picture on the screen, minus the on screen display. The video source is hooked up, but there's no picture from the video source.

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

How about this "story".... the first "replacement lamp" wasn't an OEM but a "third party" that may not have been the proper / "marginal" wattage for the system. It may have started OK... but during "lit operation" stressed the drive circuit of the ballast such that the circuit has a slightly higher "drive resistance" thus providing lower current. Your replacement (wattage??? ) may again still start but now the drive circuit is limited in output. Bulbs is always fun.... of course, as suggested earlier, check / clean the connector connects, check the voltages.... probably the initial "strike voltage" might be ok since the lamp is starting, probably the stability of the longer term voltage might be of interest.

what is your "lamp energy" setting?

elsewhere in the internet on a similar "dim lit after bulb replacement".... quote: "The light engine was replaced today. That was the ticket; 100% improvement. The repair guy acknowledged that it looked "great, even with the light on"!
Mitsubishi is covering all parts and labor. " It would appear that based on the "cleanliness" of the set, that perhaps this might be the likely point of contention.

I ran across that article as well, and that's why I asked about the possibility of a dirty colour wheel. It was the only place in the optical engine I didn't get to clean. I was trying to think what else could have caused that guy's dimness in the optical engine.

How do I check the lamp energy setting? In the menu, it's currently set to Bright, which provides the brightest setting. It seems that the TV does reach a bright display, after it's been on for a bit.

The previous lamp, it was really bad after market. In this picture, you can see how the bulb is "hard-wired" to the housing. I cannot find any identifiable marks on the bulb either...

What voltages would I be looking for and where would I be looking for them at? I figure I could maybe watch the voltage going to the ballast, and maybe the voltage leaving the ballast, but what should they be?

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I removed the colourwheel. I looked throught the glass window that the light from the bulb shines through, the one that has the colourwheel on the other side. The wheel was in bad condition. There was dirt, but it was really hard to remove. I had to use water and a microfibre cloth.

I noticed it does not spin very freely. I think I should order a replacement.

**EDIT:

After looking at the price of a new colour wheel, I have decided to clean this one! A YouTube video shows a gentleman cleaning it with isopropyl alcohol and q-tips. I will do that, very careful like, and make sure there's no smudges before reinstalling, and see how things look then.

When I mentioned the TV looked brighter after being on for a while, it could be just because it became night time and appeared brighter...

[R_J]

Re: Dim Mitsubishi WD-73738 DLP Telivision

If the (spinning) color wheel is dirty, you can bet the other 4 or 5 lenses after the colorwheel are also dirty, that piece of glass between the lamp and the colorwheel is usually a UV filter, not just a piece of clear glass, so it can get discolored over time due to heat.

[budwich]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I ran across that article as well, and that's why I asked about the possibility of a dirty colour wheel. It was the only place in the optical engine I didn't get to clean. I was trying to think what else could have caused that guy's dimness in the optical engine.

How do I check the lamp energy setting? In the menu, it's currently set to Bright, which provides the brightest setting. It seems that the TV does reach a bright display, after it's been on for a bit.

The previous lamp, it was really bad after market. In this picture, you can see how the bulb is "hard-wired" to the housing. I cannot find any identifiable marks on the bulb either...

What voltages would I be looking for and where would I be looking for them at? I figure I could maybe watch the voltage going to the ballast, and maybe the voltage leaving the ballast, but what should they be?

It appears that you have the "bright" settings for "lamp energy" ... the manual appears to be severely lacking :-). Switch the setting to "standard" to see if you notice any difference.

As far as voltages, you might look around the boards for any labeling identifying any voltages. Of course, the first thing would be to watch the strike voltage (careful... these aren't going to be a few voltages... it will "bite" you if you don't take care. From there, monitor the voltage once lit, and for a while there after to see if any changes occur.


WARNING****** strike voltages maybe in the 5KV range so be very very careful!!!! not sure what your meter will take but certainly your body won't like it .... :-( you probably don't want to try top measure this voltage. Let the lamp start, once it starts, the circuit will switch out the strike voltage section and maintain its normal operating voltage which should be in some readable / safer range.

[RJARRRPCGP]

Re: Dim Mitsubishi WD-73738 DLP Telivision

How about this "story".... the first "replacement lamp" wasn't an OEM but a "third party" that may not have been the proper / "marginal" wattage for the system. It may have started OK... but during "lit operation" stressed the drive circuit of the ballast such that the circuit has a slightly higher "drive resistance" thus providing lower current.

That may be because of the fan RPM being too low. A Mitsubishi DLP TV I saw 3 years ago, before it got condemned by 2016, I assume, uses a 12 V DC fan, just like a PC. I thought I saw a Delta in there, back in 2015, even when not a screamer, of course. That one was a socket 775 era DLP, IIRC. (said 2008 on the body, IIRC)

[ajshoe]

Re: Dim Mitsubishi WD-73738 DLP Telivision

I'd bet your light engine is dirty. When you say it gets brighter over time - what time frame ?? you need to put a another tv next to it and compare. Its most likely not the ballast or bulb. another avenue would be to buy another bulb - they're fairly cheap now.

[budwich]

Re: Dim Mitsubishi WD-73738 DLP Telivision

That may be because of the fan RPM being too low. A Mitsubishi DLP TV I saw 3 years ago, before it got condemned by 2016, I assume, uses a 12 V DC fan, just like a PC. I thought I saw a Delta in there, back in 2015, even when not a screamer, of course. That one was a socket 775 era DLP, IIRC. (said 2008 on the body, IIRC)

It could have been a fan issue but if the 3rd party lamp does not have "exactly" the same "run current" draw, depending on what it was, it may have caused a run drive issue in the ballast. The meter check, along with the suggestion of changing the "lamp energy" option to see what happens, will start the investigation.

[RJARRRPCGP]

Re: Dim Mitsubishi WD-73738 DLP Telivision

It could have been a fan issue but if the 3rd party lamp does not have "exactly" the same "run current" draw, depending on what it was, it may have caused a run drive issue in the ballast. The meter check, along with the suggestion of changing the "lamp energy" option to see what happens, will start the investigation.

Well, was wondering if a temp. sensor put it in limp mode. Also wondered if there was a sticky fan.

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

If the (spinning) color wheel is dirty, you can bet the other 4 or 5 lenses after the colorwheel are also dirty, that piece of glass between the lamp and the colorwheel is usually a UV filter, not just a piece of clear glass, so it can get discolored over time due to heat.

I cleaned the colour wheel and the UV filter. Is there more hidden lenses some where?

I cleaned the main mirror behind the screen. I cleaned the round glass ball looking thing.

Finally, we turn the TV back on, it's not bright. I go back, I push up on the HDMI cable, the video source flashes for a second, and the TV is bright. Could a bad HDMI port cause dimness or is the bad ports not related? I was thinking of trying to reflow those HDMI ports...

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

It appears that you have the "bright" settings for "lamp energy" ... the manual appears to be severely lacking :-). Switch the setting to "standard" to see if you notice any difference.

As far as voltages, you might look around the boards for any labeling identifying any voltages. Of course, the first thing would be to watch the strike voltage (careful... these aren't going to be a few voltages... it will "bite" you if you don't take care. From there, monitor the voltage once lit, and for a while there after to see if any changes occur.


WARNING****** strike voltages maybe in the 5KV range so be very very careful!!!! not sure what your meter will take but certainly your body won't like it .... :-( you probably don't want to try top measure this voltage. Let the lamp start, once it starts, the circuit will switch out the strike voltage section and maintain its normal operating voltage which should be in some readable / safer range.

Setting the setting to normal definitely makes it dimmer. The Bright setting or whatever it is, is currently the brightest for all of them.

Thanks for that info! Definitely don't want to get hurt. I believe my best probes for my meter are rated for 600V. CAT 3 (I think it's 3). I remember seeing the 600V when I purchased them. For the meter, max is 700VAC, 1000DC.

[Spork Schivago]

Re: Dim Mitsubishi WD-73738 DLP Telivision

Well, was wondering if a temp. sensor put it in limp mode. Also wondered if there was a sticky fan.

Fans aren't sticky. I checked them. Was kinda surprised, because of how dirty they where. I don't see how I could possibly tear the optical engine apart anymore to clean it. I've taken it all apart, minus removing the heatsink on the DLP chip. I don't think there's anything I missed. I got some pics if you guys wanna see the engine I got in this.