Power Supply issue?

[Trev]

I was wondering if this is symptomatic of a PSU problem {snip}

It would appear not. (taken out of context though)

 

[everthewatcher]

Update.
An exchange of PSU boards between my two units shows that the problem is NOT with the PSU.

Not the main one - as an electronics engineer I'd have put money on that - but my first first check would be any on-board regulator supplying the tuner modules as it seems to be common to both.

I'm not pulling mine apart ATM so looking at the PCB picture in the Wiki there are a couple of power devices in the right area that could be linear regulators but I can't read the numbers. There are also quite few SMPSUs scattered around the board too. Another possibility is the (presumed) I2C control interface to the tuners and decoders.

 

[Black Hole]

 

[moosey]

Its not the tuners or the supply to the tuners as I am getting good signal levels reported and 100% quality at all times. The problem would seem to be in the circuitry that does the decoding or the processing of the decoded signals. In the picture that Black Hole kindly posted above, the heat sensitive parts were the chip with the heatsink on, three chips to the left of it, and the one immediately beneath it (partially obscured in the picture by the lower part of the heatsink). The regulators and the SMD capacitors on the main board did not seem sensitive to the hair dryer or freezer spray. I ran out of freezer spray before I could narrow down the culprit further, but if it is one of these chips then any repair would seem to be unlikely.

 

[af123]

hree chips to the left of it

RAM if I remember correctly, I'll track down my high-def. images

and the one immediately beneath it (partially obscured in the picture by the lower part of the heatsink)

That one is the flash memory.