Sony Betamax Problems

[tvcollector]

Over the last few years I've obtained a SL-HF450 and a 750.. I've noticed both of these units have the same problem... When I press the power button to turn on the VCR, the VCR will power on partially, and the power button light doesn't come on either, but when powered on the channel display comes on and your able to see the BII & BIII speed indicator but as far as anything mechanical does not come on, and inserting the tape does nothing and also the Hi-Fi indicator and VU meters are not coming on as well.. It sounds like some due indicator has detected moisture or something, but I don't think these models have that feature... Does anyone know what this problem could be? My guess there is issues in the Power supply...

Thanks...