Re: Tek 2230, almost fixed but with a problem out of my competences


Albert Otten
 

On Tue, Jun 8, 2021 at 03:55 PM, chipbee40 wrote:


I found in my workshop notes that I had a 2230 stuck on 2sec Timebase readout,
the notes stated the cause was dirty contacts on 1k/4k switch and roll/scan
switch. I'd guess I either replaced the switches or deoxited them first maybe.
It's striking that your scope had the same symptom as originally in Federico's scope.
In Store mode the 1k/4k switch is responsible for supplying the proper 1k/4k REF voltages to HOR REF, so that's a good point. As it happens Federico checked HOR REF voltages at the timing switches and they proved correct in all time/div settings (-7.91 V at 1k and -1.52 V at 4k). In 4k mode switch contact 2 is open anyway, dirty or not. In Non-Store mode the 1k/4k REF switch is not used at all.
Also taking into account the findings in the last messages I doubt a dirty 1k/4k is the fault. But I might very well be wrong here.

Albert

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