Many years ago I was given
an old Telequipment DM63 - a dual-beam storage scope. These 'scopes
have a true dual-beam CRT, so there is provision for two vertical
plug-ins; my one came with two V4's which are dual-trace units
meaning that in total, the 'scope supports up to 4 traces.
Unfortunately, there was a major fault - which of course is why it was thrown away. The scope basically worked, but you couldn't trigger on any signals because of the failure of IC1 in the timebase module.
This is bad, because IC1 is a custom-made Tektronix chip that is no longer available. There was no option but to build additional circuitry to replace the functionality of IC1.
In this section...
- Main repair - Details of the initial fix to replace the custom IC.
- Other Faults - Everything else that went wrong with this example.
- 'Scope 2 - Details of the many faults and complete restoration of another DM63.