 CRT ocilloscope issue
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Conundrum
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Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061
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Yes. Use the scope you just repaired to test the caps you took out with a frequency generator and graph the voltage drop with increasing frequency 
the circuit you want is generator---known R---SP-+Capacitor--Gnd
Please make sure the capacitor is discharged before testing, I usually short them for 1 hour now after blowing a meter's fuse from a "discharged" photoflash which had recovered over 70V.
see 
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BigBad
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Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
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Yay. A burnt out resistor huh? I would have thought that that was a rarer type failure. Good going.
brandon3055 wrote ...
I did remove and test a few of the caps because I know they tend to dry out after a while but the few a measured seemed fine although the values I measured on a few of them were a fair bit higher then the rated values. The 47uf caps read about 52uf but I just assumed the manufacturing tolerances were higher when they were made. Or could that be a sign of failure?
No, a lot of caps are quite wide specced, like 20% or something. That's well within spec.
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