Sony EVM-8010 / 9010 power on issue

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Hello all,

It is my first post here. I am a 35-year-old hobbyist from Australia. I like to tinker with CRTs and hifi, like I'm sure many of you do too. I have been a member on AudioKarma for some time and found their community to be very helpful and patient.

I am hoping to get some help with a little Sony Combo8 unit I've had for a while. The issue it has is that when I switch it on, there is a small 5V relay behind the VTR block that clicks repeatedly and the VTR block does not come on. Every now and then (maybe once in every 50 attempts, or after a period of time switched off) the relay will click once and the VTR seems to switch on, display numbers on the LCD etc. The eject button does not work.

I purchased the OEM manual from Sams Website and was looking at the schematic for the power supply on the VTR. Here's an excerpt:


What I've noticed is that when the relay clicks repeatedly, the collector voltage on Q821 is constantly fluctuating between 3.5V and 5V (it should be a steady 5V).

I'm wondering what could be causing this to happen? I have replaced all of the electrolytic capacitors on the little PSU board but to no avail. Some of them had quite high ESR readings but most of them were fine. Any other ideas on this one?