We've had this Sony SLV-690HF VCR which has worked reliably for many years.
Just stopped working. No motor action, no LEDs or display on.

It appears it could be a power supply problem. I checked the fuse which is
okay as well as the power cord continuity. In fact, when I plug the machine
in, I notice a single flicker of the power LED and then nothing. Otherwise
nothing is displayed on the front panel. When I unplug the VCR for a few
seconds and then plug it back in, only the single quick flash of the power
LED occurs.

Inside is an SR700 Mitsumi switching power supply. I have that board out
and would like to know what I should be looking for. There are 8 pinouts
near the end of the board. Can someone tell me what voltages I should see
for a properly working power supply in this VCR or for the SR700?

And then what parts can I check and how?

Is it worth finding a new SR700 power supply and how much would it cost? Or
should I try to test and replace some onboard components?

Thanks for any help.

Allen