Re: 475 Time Base Setting Problem


 

However, even if it was out of its detent it would still get some amount of voltage from R1070, right?
Sure, anything between +50 V and +15 V.

Either R1083 or R1084 has effectively gone o/c. is my hunch
Definitely, since sw. pos. 9 and its circuit still is a strong candidate. The sudden and complete failure of the affected timings speaks for a broken R over a bad switch contact.

It may still be worthwhile to check whether the working tim/div settings are correct within a few %.. If they are, I wouldn't worry about the close-to-zero (wrong?) voltage you find even at those apparently working speeds.
After all, there might be a failure somewhere in the integrator that allows it to operate at all but the highest-ohmic settings. If most timings are ok, that possibility becomes very unlikely.

Raymond

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