Originally Posted by bps1
Curious about the model number for the DMD chip. I have this problem with my 1.5 yr old (barely used - 70hrs or less) HD66 that just started showing the white pixels today. I only have 3 white stuck pixels. Curious if the "thermal paste" you mention could be my problem. If I understand correctly, this paste dries over time such that it does not make good contact with the thermal sink and thus the overheating causes the DMD chip to begin to fail (in the form of "stuck" pixels showing up as white dots)? Can I just buy some of this paste on Amazon and reapply to prevent further chip failure? What is the model number of the chip you purchased and where did you purchase it? I've looked on the web and see some DMD chips that may fit the description (1272-6038B)?? for $135. Does this sound about right? Any luck talking to Optoma about the problem? Curious about the steps to replace this chip and/or add the paste - I'm fairly handy, but would appreciate some insights/tips/tricks to opening the unit and making the repair. (any diagrams or photos would be helpful)
Teh DMD chip in my HD66 failed after about 2000 hours. The stock chip has a grey silicon pad to connect it to the heat sink. My understanding, based on opinions I've read, is that these thermal pads do not conduct as well as thermal paste. I also read that the contact doesn't need to cover the whole chip - the cooling properties spread with the cemented paste. I hope I did my research right. My first chip replacement resulted in a pretty rapid failure of the replacement chip because I omitted a heat sink contact material, so I can assure you its needed. I just performed my 2nd replacement last night (new, $75 off ebay) and used silver paste. The paste is probably is not used in factory assembly because the pins sit around the space where the heatsink contacts the chip - misapplying the paste could lead to it touching pins. However, I didn't find it hard to apply.
The thermal pads could be bought off ebay, but I can't find them at Microcenter or RS.
A tip for when you make the repair:
If you happen to get any vertical white lines or horizontal black bars after installation, take it apart again, blow the contacts clean with a compressed air can and make sure the DMD chip-holding card is firmly attached to the motherboard. I thought I'd screwed the pooch, but a quick reassembly with this attention to detail put everything back in working order. I've open up that space 4X now. I'm getting quick and not ALL of the screws are needed - the thing is a little over built.
While you're at it, clean your color wheel off with some alcohol on a q-tip. Obviously, spend some time cleaning out all the accumulated dust too, mostly in the fan.
I do need to find a way to remove two dust blobs halos I see when the screen goes black (inside the lens I guess) and a small amount of light bleed into the lower right corner (also only noticeable with a black screen). These complaints are minor, but it would be nice to know how to deal with so maybe it'll perform like new again.
Overall, I'm never buying a first run of a projector again - even a minor update like the HD66 over the HD65. I've learned that lesson!