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Old 21st Apr 2017, 6:59 pm   #3
Clive G3GJA
Diode
 
Join Date: Apr 2017
Location: Anlaby Common, Hull, East Riding of Yorkshire
Posts: 4
Default Re: Poorly HP 8593A SA with PSU problem

Thanks for looking David and hopefully you'll come across it next week.

The start-up resistor (100k 2w) was the first thing I looked at but I can't do any hot checks until I can simulate the loading and power switch.

It's just not possible to find out whether the always on 18v supply is working whilst the PSU is in the chassis and there's no status LED for it.

It's likely that another fault has developed since the earth leakage was fixed; it looks as though there's a power good feedback so anything in the SA could upset that.

Even when I get it powered up I know there's a RF fault on it, allegedly making it BER, so probably some clot stuffed several watts into the front-end. At least I know the tube is good as the display looked quite sharp for the short time it appeared.

Clive
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