475/Repairs

Capacitors

The 475 series scopes use tantalum capacitors. They are known to short out and bring the scope down.

Typical symptoms will be no trace, or powering on and going off in few seconds due to built in fold-back protection. The shorted capacitor in the power rails will down one (or more) of them and causing entire scope to be non functional.

Quick way to troubleshoot is, after powering off and ensuring all capacitors are discharged, check resistance to ground on each power supply rail and identify the shorted power rail. Then trace the offending tantalum capacitor with the help of schematic.