OP should check the serial is covered in the downloadable PDF's.
The more recent instruments are not covered in these manuals.
However there are addendum to bring them up to date.
To reiterate, including Macman's suggestion, Download the service manuals.
Run through the 12v PSU troubleshooting tree and if stuck, post back here
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
good luck,
--marki