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Old 01-01-2017, 06:24 PM
Bill R Bill R is offline
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Join Date: Oct 2004
Location: Jackson, TN
Posts: 893
Well it has been awhile, but I thought I would get back to this project. I checked the voltages and the 5,7, and 20 volt supplies are there. I found a problem on the analog board with a broken trace and repaired that and one transistor in the ringing circuit. It now appears to work on the inductance side. I can zero the leads, it will give a value, and the ringing test seems to work. But capacitance test still does not work. The oscillator is working, and I do have the 200 hz sort of square wave on IC12 pin 12. I do not have any pulses on pin 11 of the digital board. I have traced back to IC14 which is just a D flip flop with set and reset. I have pulses at the clock input, but none on the Q output pin 13. The D input is 7 volts, and as long as the set input pin 8 is high I will not have any output. However pressing the cap value button pulls the set input low through TR05 an with no set or reset I should have pulses on pin 13 the Q output, BUT I do not. There is no pulses on the output even with no set or reset. That would explain why no pulses on pin 11 feeding the analog board. My question is would this not have to work for the inductance side of the tester to work, or would it only effect the capacitance test?
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