I've tried the following with no success:
*formatting
*clearing settings
*two different hard drives, both scanned for errors and come up clean.
*3 different firmware (was using latest 061009B)
*different aerial sockets and cables (even though there is no problem with signal strength)
*retuning channels
*visual check of internals - no visible sign of problems.
*and finally giving it a good smack... (although this may seem tactless it works for some old tvs I've had the pleasure of 'fixing')
*formatting
*clearing settings
*two different hard drives, both scanned for errors and come up clean.
*3 different firmware (was using latest 061009B)
*different aerial sockets and cables (even though there is no problem with signal strength)
*retuning channels
*visual check of internals - no visible sign of problems.
*and finally giving it a good smack... (although this may seem tactless it works for some old tvs I've had the pleasure of 'fixing')
Looks like you've covered most of the bases. The only thing Ii can suggest is to check the output of the power supply, 12, 5 and 3volt rails if possible.
