After a momentary grid powercut, my FVT 5000T no longer booted up and became stuck in a loop after initially displaying the Humax logo on the TV screen on startup. The aerial loop-through opened briefly, and the LED changed from red to blue and then back to red. Digi Repairs were unable to repair the unit and diagnosed a problem with the microprocessor.
With the lid off, I used a hair dryer to direct hot air onto the microprocessor heatsink from a close distance for a few minutes until the heatsink was hot to the touch (about a similar temperature to its normal operating temperature, which I measured as 39°C at ambient 23°C). I then connected the power lead to the unit and pressed the Standby button on the board. The hard disk started up and a programme on the channel selected previously on the unit was displayed on the TV. The 5000T, which was configured to be always ON, now works normally again.
CAUTION: There is a risk of damaging the microprocessor and other components if excess heat is applied to the heatsink.