Background: its a big and common problem with the MSO-X 3000
oscillopes that the PSU is on even when the oscilloscope is off. The age
of these scopes means, that that the PSU now (typical 2020 and forward...)
dies with a gigantic BANG. The big capacitor dries out, and several other
components dies aswell. An original PSU is 1000euro, but a quality
replacment PSU is very easy to find and fits in perfectly.
The RPSG-160-12 is almost a plug and play replacement PSU. Important to
get the G-version, RPSG, and not the RPS.
Link to mouser here: https://www.mouser.dk/ProductDetail/MEAN-WELL/RPSG-160-12
The connectors from the old PSU can be moved over to the new - they have
same pin distance.
Connections from the PSU board in the oscilloscope to the new as listed above.
The CN2 connector from the old fits perfectly on the new PSU. The CN3
connector can be moved also, but in this case a put in a new Molex and
just move the cables from the old to the new without crimping new.
The holes in the new PSU are placed a couple of mm aside the old, so you
need to file a tiny bit in the holes of the new PSU.
When that is done, you can firmware update your scope at the same time,
mine was several years old.
https://www.keysight.com/us/en/lib/software-detail/instrument-firmware-software/installing-infiniivision-3000-xseries-oscilloscope-firmware-2014548.html