BENQ W1070+: Occasionally unresponsive with static image

Hi all!

We have a BENQ 1070 projector which we've been using for a few years now. In the past few weeks however, it has started to act up occasionally. Most of the time it will work just fine.

Sometimes the screen will go black with a handful of random white pixels spread out. At this point, it will be unresponsive, unable to be shut down via power button or controller. Disconnecting the display cable can make it show a different static pattern.

At this point, the only thing to do is to pull the plug. Reconnecting it shortly after will have the "lamp" icon on the projector blinking red. Waiting a little longer before plugging in will have it turn on, but immediately malfunction in the same way. Leaving it disconnected for a few hours, then plugging in and turning on it will work fine.

Anyone have a clue what this might be, and how we might fix it?

Our current hypothesis is the hdmi connection to the main board going bad in some sort of heat-sensitive fashion, but we haven't opened it up yet.

Thanks!