Re: Ringing on 2235 100 volt supply


John G
 

Hi Raymond,
Let me clarify a bit. Table 6.4 in the service manual shows 40.0 P-P Ripple (mv) as the limit on the +100 V supply. I see about 90 mv P-P as pic 1 shows. Scope set at 20mv per div.
If it wasn't for the ringing it would be in spec. I see the same result measuring itself or on another scope. Measured at Test Point W954 which is adjacent to C954.
The thread that I believe is the same issue, but I couldn't find the photos referred to is:
https://groups.io/g/TekScopes/topic/7646253#62131

I added more picts showing the horz sweep problem:
https://groups.io/g/TekScopes/album?id=242594
2 is normal, 3 is after it fails and settles down, 4 is the transition between the 2 states, very erratic sweep. Moving any control, switch or tapping on components doesn't cause it to fail or fix it. Random when it happens, usually about 30 minutes after you turn it on. It will fail for 5 sec to 2 minutes, work properly 10 sec or 30 minutes. Totally random. All other functions seem normal. S/N B024573
Thank You for any light you can shed on these issues.
John

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