[Test-Equipment] Tektronix DC-502 Digital Multi-meter

[Ray LaRue]

I have the above Tek multi-meter which I have owned for many years, but 
only used sporadically.  It has developed a problem which I thought I 
might draw some wisdom or prior experience, from the group before I dive 
into it.

It is mounted in a TM-504 frame which is working well with other 
modules, bu it is flashing random numbers in any position of the 
selector switch.  It does so even with the leads shorted in any setting, 
AC, DC or ohms.  Also with the input selector on internal or external.

Does anyone have any experience with such that they might give a clue 
what to look for?  I have the manual.

At 81 years, any assistance to shorten the troubleshoot/repair, will be 
appreciated.
Ray, W4BYG