Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
The lamp would not cause this issue.
What you are experiencing is symptomatic of failure of the DLP chip. This is a very common problem with all DLP based tvs. What is happening is that DLP chip, which contains millions of tiny actuated mirrors, starts to freeze up. Those "stuck" mirrors result in a white pixel on the screen. They cannot be unstuck or repaired, the entire dlp chip has to be replaced. You will continue to get more and more dots appearing, until they cover the screen.
There are many blogs and youtube videos detailing the process, if you're inclined to do it yourself, though I would not attempt it unless you are skilled and experienced with electronics repairs – you can easily do more harm than good. It is about a $200 part. If you have a local tv tech out to do it, figure on around $300-400 total for the repair.
Even though it is past the warranty period, it is also worth a call to mitsubishi. Because this was such a common problem, they will often offer to cover the cost of the part, if you pay the labor costs.
If you'd like, I can help with finding the part, finding a repair shop, or even recommending replacement models if you'd prefer to go with a new tv instead.
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