56HM195 Blue Ghosting/Smearing

Moderator: Angel

Post Reply
DaveGinSD
Contributor
Contributor
Posts: 11
Joined: Sun Apr 11, 2010 9:14 pm

56HM195 Blue Ghosting/Smearing

Post by DaveGinSD » Sun Apr 11, 2010 10:21 pm

I've had this set since about March of 2007, its first lamp blew out in June of the same year, and was replaced under the manufacturers warranty and has been great ever since, under heavy use. I believe it could use a bulb replacement, I checked the lamp hours in the service diagnostic mode and it said over 12,000 hours, but I don't want to by a bulb if it's not really the problem

About a month ago my wife was watching and noticed, what I can only describe a blue ghosting or smearing that trails off to the right objects. Whats odd is every part of the picture doesn't seem to have the problem, for example if I were to put up a 5 bar log steps test pattern, only 3 of the 5 steps would have this "ghosting". Because there are certain intensities that don't do this, you can have scenes that are totally unaffected and others that are down right unwatchable.

Another example would be a horizontal grey ramp will have a vertical stripe of the ghosting and up towards white is more of an interference of the same blue color. The ghosting will move with a moving picture, it's an odd issue and has me quite stumped. I've attached some pictures that can show the problem better than my descriptions, although not all the problems show up. If any one can help me out, I would appreciate it. I do have access to the service manual, and am pretty comfortable taking the set apart. If any one needs more or better photos of the issue I can provide those as well.

Thanks in advance.
TV-10 edit.JPG
TV-10 edit.JPG (15.03 KiB) Viewed 2976 times

TV-8 edit.JPG
TV-8 edit.JPG (18.6 KiB) Viewed 2976 times

TV-6 edit.JPG
TV-6 edit.JPG (15.51 KiB) Viewed 2976 times

darkart77
Tech Junkie
Tech Junkie
Posts: 189
Joined: Mon Mar 22, 2010 4:34 pm

Re: 56HM195 Blue Ghosting/Smearing

Post by darkart77 » Tue Apr 13, 2010 8:47 pm

It's hard to tell, considering the pictures the vertical line tells me that it can be the DMD board, however the pother picture looks like your lamp might be out of position it lights brighter to the left side. Start by checking your lamp pull it out from the housing. the lamp won't cause the vertical lines you see there. Unfortunately you might have to have a tech check your tv.

DaveGinSD
Contributor
Contributor
Posts: 11
Joined: Sun Apr 11, 2010 9:14 pm

Re: 56HM195 Blue Ghosting/Smearing

Post by DaveGinSD » Thu Apr 15, 2010 3:16 pm

That's funny you noticed the one side being brighter, that's a separate issue I've had for a long time, I didn't think it would show up on the photos. My understanding is that it's the light tunnel being out of alignment. That problem really doesn't bother me too much, you can really only notice it on a all black screen. My big concern is the blue smearing, it actually smears off to the right from bright or mid toned objects next to black backgrounds, it also varies in intensity.

DaveGinSD
Contributor
Contributor
Posts: 11
Joined: Sun Apr 11, 2010 9:14 pm

Re: 56HM195 Blue Ghosting/Smearing

Post by DaveGinSD » Mon Apr 19, 2010 2:00 am

I’ve noticed something else that the set does related to the blue ghosting issue that I’m hoping may help someone else out there narrow down the issue or at least what part of the set to look for issues. When the contrast control is moved up and down the severity of the issue changes. If I turn the contrast down low enough the problem will almost go away entirely, unfortunately it also makes the picture too dark and unwatchable. The way I see it is the issue happens on all inputs so in my mind that would put the problem in either the signal board power board or in the light engine. I kind of don’t think the light engine is the problem because when there are no tones that cause the problem in the scene, the TV still can put up a near perfect image, I know this doesn’t completely eliminate the light engine, but it would seem to me if the engine was the issue the problem would occur all the time.

Post Reply

Return to “Toshiba DLP Discussion”