Samsung DLP LED HLS5679wx/xaa Picture has gone bad?

I had the same issue this past summer. I too had fixed the power cycling issue (twice in 2 years). I don't believe it's the power board this time but admit I can't be 100% sure.

I immediately got a Mits 73" to replace it and "gave" the Samsung to the delivery guys with the remote, manual, service manual, all notes and forum print outs and wished them the best with it. I mainly just really needed it taken away.

With the lamp based Mits, I see rainbows every now and again unlike the LED-based Samsung and I'll of course have to change the lamp every so often. Oh well. I know the LED-based system is suppose to be long life (that's one reason I got the Samsung) but it's only going to last as long as all of the other components in the HDTV itself.

I gave the 73" to my brother after testing the lamp-based DLP "waters" and now have the 92" Mits. After 4-5 years, I will more that likely go front projection once wireless 3D HDMI works like butter or better yet, get a new OLED 92" flat screen or whatever the new/not too expensive thing is in 4-5 years from now.

I have the same set, with similar issues. Mine strobes in in some picture settings, and a blue mask with a slight spiked fence on the top edge grows up from the bottom.
From your pics I see it seems to also be related to the blue gun.
It is likely the led driver board (unavailable). You can also try this to isolate:
power off, remove ac cord, remove the 2 screws that hold the light engine chassis in, and the dvi plug on the left so you can slide the assembly out a few inches. On top of the led light assembly is a small circuit board. The connectors from left to right at blue, green, red. These are all different pin count connectors, BUT the connector at the led module end are all the same. Gingerly squeeze the plug at the led module end and remove the plug from the blue and green leds and swap them at the led module end. slide the light engine back in, reconnect the dvi cable. Turn it on and watch your picture. Now obviously the colors will all be off, but the artifacts and smearing color is what you need to look at. If it remains blue, then there is something strange with the blue led. if it changes to green, then it is the led driver board, or possible the dmd board that generates the color signals. If I had a service manual I would check the drives for the 3 colors where it leaves the board as that couls also be the culprit.

Hey! This is the exact issue I'm having! Ever get it fixed?