Riddled TV Repair Forum

DGINSD · Joined: 20 Mar 2010 Posts: 6 Location: San Diego

I've had my 56" DLP Tosh set for about 5 years with little issue. my wife notice this while I was at work, when there is a bright part of a picture next to a darker part there is a bright blue ghosting present. If I put up the greyscale test pattern (4 bar) the "ghosting" appears as blue edging to the right of the grey bars, oddly enough it only seems to be on the top white bar and the 2nd from the bottom grey bar. There is also some slight yellowish ghosting on the left of these same grey bars almost like how a CRT se would look if the blue CRT was out of convergence. Another odd example if I put up a 60% grey flat field, the bottom 4/5 of the screen is grey with this same blue colored "static",or "snow", the top 1/5 is fine just 60% grey field. The area where the ghosting is changes depending where the contrast control is set

I know its difficult to convey what I'm seeing with words so I'll try and get a good picture of the issue to post.

I've tried already a reset using the setup menus reset option. I've done a hard reset disconnecting power overnight. I've done a combination of the two menu reset, followed by a hard reset. I did a minor cleaning of the vents and insides (what is exposed by removal of the back panel), one of the vents was clogged so it is possible something overheated.

I'm pretty comfortable going into the guts of the TV, and I an pretty good at soldering. I've replaced convergence IC's before, so I'm not completely helpless. Any help as to where to look for bad components would be appreciated. I have a feeling Its either the light engine, or signal board, I'd prefer to replace small components than either of those. Please help.

Google

DGINSD · Joined: 20 Mar 2010 Posts: 6 Location: San Diego

Just kinda a secondary question, can a very used bulb cause this type of problem? This DLP set has over 12000 bulb hours on it, and the first bulb didn't make it past the first year (it fell under Toshiba's extended bulb warranty). Is the only bulb related problem, no picture, or could a severely depleted bulb cause other picture issues? My guess would be, no, but I only know the basics about the inner workings of a DLP.

An update on what I've done, I removed the main electrical block which includes all the PCB's and the light engine, and looked around for obvious burnt components or the smell of burnt components. I gave the guts a minor cleaning from quite a bit of dust, that was just about everywhere. I ran the self diagnostic described in the service manual, which told me absolutely nothing. All of this to no avail, and to top it off my back-up 47" Panasonic CRT set's convergence IC went out or requires re-soldering, so I'm stuck watching this Tosh till I fix the Pany.

DGINSD · Joined: 20 Mar 2010 Posts: 6 Location: San Diego

I have some pictures that can show the issue rather well, but I'm not all that computer savvy and I can't figure how to, both shrink, and post them. If someone could help me out with this, that would be great.

kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

email them to t1941@riddledtv.com

I'll get em posted for you.

kuhurdler · Joined: 28 Dec 2006 Posts: 2879 Location: Overland Park, KS

Google

DGINSD · Joined: 20 Mar 2010 Posts: 6 Location: San Diego

Something else I've noticed that I hadn't noticed before, the fan that cools the cable card slot is always on. Its not super loud or obnoxious, you can't even hear it unless it's dead quiet or your right at the TV, but my concern is the fan wearing out. Is this fan always supposed to be on?

DGINSD · Joined: 20 Mar 2010 Posts: 6 Location: San Diego

Iâ€™ve noticed something else that the set does related to the blue ghosting issue that Iâ€™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 donâ€™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 doesnâ€™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.

1gr8sysop · Joined: 24 Sep 2010 Posts: 2 Location: Alabama

Did you find out the cause of this problem? I'm having the same issue with my dlp. I have been reading forums for days and it seems that a few people have the same issue but nobody seems to have the answer to why. Please let me know if you have figured it out. Any help would be appreciated greatly. If I find the answer I will let you know...