Load buzzing - Siglent SSA3021X Plus / SVA1032X

[eloso]

I haven't used my SSA/SVA for a while but it has been in standby mode i.e. power connected, and on/off button illuminated. The unit suddenly started buzzing extremely loudly. Loud enough not to be just a nuisance but to be cause of real alarm - like something is about to go bang inside there.   I was three rooms away when it started and I came to the lab to investigate.

I pulled the mains cable out the back and the buzzing continued for say, 5 seconds then stopped.

It sounded like 100hz. Certainly not much higher.   

The unit is 9 months old.

This is the worst kind of happening of course - it seems dine now on reapplying power. I could send it back and it could sit on some tech's bench for another 9 months and the problem not occur again.  I shall conitnue to use it but may not leave it powered when I am not  with it.

Anyone else ever had this fault ?  I am guessing it is some kind of smps happening, so even if it wasn't with an SSA, experience of this kind of problem with any kit might be interesting. Or perhaps just some ideas about what could cause it ? The switcher will operate at much higher frequencies than what I heard, but did the frequency of the switcher drop to 100hz or so ?


Its all a bit of  pain, expecially as the unit has been upgraded so I don't want to send it back.

I have asked this before, but no-one ventured to reply - I have a full memory backup of the machine state when it was purchased - done with a script kindly provided through this forum. I have not seen how to recover this backup and really don't want to start playing around manually trying to restore mtd partitions without some insight into how everything is structured.  Anyone know how to do the restore ?


Kind Regards

Eloso

[nctnico]

Just send it back for repair under warranty. If you didn't open it, then there is nothing to worry about. Trying to undo the hack is only going to make things worst by the look of it.

[tautech]

Interesting. PSU problems are not unknown but rare.
Do you have a variac by any chance to check what it does with a 110VAC supply ?

AFAIK these use the 4ch X-E DSO PSU and reducing the input to 110VAC did shut up a much older one but it's hardly a long term solution.
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg3619647/#msg3619647
Later discussion post 1683 and on.

Your local reseller should be able to perform the warranty PSU swap.