Philips 42PFL9603 strange behaviour

[PowerAmpFreak]

This set, a Philips 42PFL9603H acts very strange.
First turn on, it does not react to remote or input signals. Backlight comes on, PSU voltages are fine.
I have to turn it off and back on to have it operational.
Sometimes it requires a third off and back on to have the sound up and running.
It has the latest firmware, according to Philips download site.

This obviously looks as a mainboard problem, but when it's on, it runs perfect.

Phew....

[PowerAmpFreak]

Re: Philips 42PFL9603 strange behaviour

It appears if Input source are selected any of the HDMI inputs, and there is no signal applied to it, the set will sort of "crash" during bootup. It retries to boot, set starts up, and goes through the loop again.
Set has to be pulled from mains to exit this, and after one or two times it can operate correctly.

[tom66]

Re: Philips 42PFL9603 strange behaviour

Check all voltage regulators, particularly any that supply the main processor or HDMI input chip, if there is one.

[PowerAmpFreak]

Re: Philips 42PFL9603 strange behaviour

This ended up changing the mainboard. First one I've recieved brand new was bad. It went into protection right away, complained about internal I2C error.
Got a second one, which did the trick and set is back to operation.

[freakaftr8]

Re: Philips 42PFL9603 strange behaviour

Yes there are two 6 pin regulators that like to fail on the philips magnavox mainboards.

[Caleb]

Re: Philips 42PFL9603 strange behaviour

@freakafter8 where might these regulators reside? I have 3 Phillips TVs with main board troubles. One acts a lot like the op described. Are they actual voltage regs?