New member here.
I've just done a successful repair on my BCF power supply.
The main switch mode chip TNY268P had failed, got a replacement (actually a TNY268PN) on eBay for £2.30 (UK price), soldered it in, success! I'd already checked the capacitors, but they were all OK.
This is a fairly simple repair if you have soldering experience or you could get a tech to do it for you. Be very careful of the high voltages on the PSU board when testing!
The PSU 7 pin connector should have the following voltages on it: 3 pins at 0v, 3 pins at 5.4v, 1 pin at 4.9v (the one with the red wire).
Hope this helps someone fix theirs. I don't have the schematic, but it's a mixture of the TNY268 data sheet and the TL431 data sheet, both available online, as are a couple of guides to opening the unit up and dismantling it.
Good luck!