[time-nuts] 58503A alarm light on, but :SYSTEM:STATUS? indicates all is ok

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Wed Apr 1 14:15:37 EDT 2015

On 1 April 2015 at 17:39, Chuck Harris <cfharris at erols.com> wrote:
> I can't help but notice that you have several of these entries:
> Log 067:20150101.00:00:11:  5V is out of tolerance, value: 5.52
> Log 068:20150101.00:00:11:  15V is out of tolerance, value: 19.46
> I think you better look into them before anything else.
> -Chuck Harris

I am aware of those. They have only ever happened immediately the unit
has power applied - never once it has been running. It is very
intermittant, so very hard to fault-find. I replaced one capacitor in
the SMPS, and have gone around the others with an in-circuit ESR
meter. I have had a DVM in peak-hold mode measuring the voltage and it
is not going as high as those numbers indicate. I really don't know
what is the cause of them, but I'm fairly confident that the power
supply is not actually putting out those voltages.

But note that the alarm LED is on now, but there have not been any
reports of out of tolerance voltages.

Perhaps I have no option but to replace this supply, just in case it
is that, but they are not cheap, and I'm not convinced the PSU is


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