Sanyo IC5750 replacement problem

[ridgerunner]

I have a Sanyo DP42849-01 that had the problem where the green power led would come on for 10-20 seconds, then recycle. The set would never power up. I replaced IC5750 on the main board, I had the hynix chip, not the quimondo, and now the set will seem to power on but it sounds like machine gun fire through the speakers and no picture. I seems as if the main board may be cycling on and off rapidly. All voltages look good on the power supply side.

Any ideas?

Thank you