No power or anything

So I had nearly the same thing, only no intermittent behavior - just alive one day, dead the next.

I took my unit to an electronics repair place. For $25 they diagnosed AC power supply failure and offered to charge me a total of $110 to refurbish the machine.

I balked since we paid far less for the unit on Ebay ($70 or so).

The store gave me the parts list for the estimate though - and I bought the parts and did the work myself. Total another $25 approx, plus time. If you are up for some small electrical work, get a soldering iron, some electrical solder and a soldering wick. You will need, some wire cutters / strippers, and a screw driver too. you may also want a Dremel tool with a cutoff wheel.

Anyway, just replace the first 4 diodes after the transformer leads to the main board and replace the transformer.

The diodes can be from any of a number of manufacturers - mine are Vishay part number 1N5408 - 0827J. The critical part of this part number is the first 6 characters. Put the diodes in using the orientation guide printed on the main circuit board (otherwise risk putting them in backwards).

The transformer part was a Stancor, part number P-8657 - it converts standard wall AC (117V at 50 or 60 Hz) to AC at 12V, 2A. This part is BIGGER than the OEM Hang Fung transformer. I used a Dremel tool and cut out the mounting pieces for the OEM transformer from the main housing. This made enough space to fit the new transformer. Now the new transformer is held in place by clamping action of the two-piece main housing when the screws are installed. I DO NOT KNOW IF THIS IS SAFE, SO YOU ARE WARNED!!!

Unit works fine now. Mouser electronics has the parts and will ship USPS in a few days.

Thanks to VY Electronics, Rochester, MN for diagnostic work.