| Electronics > Repair |
| Keithley 2002 repair help |
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| nikonoid:
With input from the forum I did a "sponge bath" for a meter. I would saturate small section with liquid for a minute or two, then wipe it out with dry q-tips. I did it over and over again working one section at a time. Two days later the meter is now in close to PERFECT condition. It passes all self tests even on cold start. Current still have a bit of a drift on start and stabilizes after 10 minutes. Ohms seems to read right. Again about 20ppm drift from cold to warmed up. I also noticed noise during OHM measurements of ranging from +/- 1ppm to about +/-5ppm. This might be as good as it gets considering I am running meter without top shield and case. The plan now is to finish recaping, buy shield and case from Keithley and do full evaluation of the meter. I can take it through few more rounds of cleaning, if becomes necessary. Thank you everyone for staying with me on this and specifically thank you Kleinstein for your continued help and comments. |
| saturnin:
Although it is definitely great progress (considering the initial state) and passing self test may be good indication there is no critical failure, I would still hesitate to declare the unit anywhere near to "perfect" condition. In such old units there still might be hidden serious issues (intermittent glitches in readings, slow long-term drifts...). I saw multimeters which were passing built-in self test with flying colors, but after detailed verification of their performance it was obvious there was an issue. It could take weeks or even months to find and solve these ones... |
| TiN:
Well, that to be determined by full low-level calibration and verification (which in turn require access to 5700A + booster) :). |
| Le_Bassiste:
--- Quote from: saturnin on October 15, 2017, 02:44:03 pm ---Although it is definitely great progress (considering the initial state) and passing self test may be good indication there is no critical failure, I would still hesitate to declare the unit anywhere near to "perfect" condition. In such old units there still might be hidden serious issues (intermittent glitches in readings, slow long-term drifts...). I saw multimeters which were passing built-in self test with flying colors, but after detailed verification of their performance it was obvious there was an issue. It could take weeks or even months to find and solve these ones... --- End quote --- so, how would you actually declare this unit to "anywhere near to "perfect" condition"? what are your criteria to do so? |
| Zucca:
--- Quote from: nikonoid on October 14, 2017, 04:32:05 pm ---With input from the forum I did a "sponge bath" for a meter. I would saturate small section with liquid for a minute or two, then wipe it out with dry q-tips. I did it over and over again working one section at a time. --- End quote --- Which liquid? 50% distilleld H2O and 50% IPA? Congrats Sir nice job! :clap: :clap: :clap: :clap: --- Quote from: saturnin on October 15, 2017, 02:44:03 pm ---Although it is definitely great progress (considering the initial state) and passing self test may be good indication there is no critical failure, I would still hesitate to declare the unit anywhere near to "perfect" condition. In such old units there still might be hidden serious issues (intermittent glitches in readings, slow long-term drifts...). I saw multimeters which were passing built-in self test with flying colors, but after detailed verification of their performance it was obvious there was an issue. It could take weeks or even months to find and solve these ones... --- End quote --- Yes you are right, but I believe nikonoid will not give up easly. Moreover the probability a SELF PASSED unit has more problem inside is cam'on small. It happen to me too, but it was a single event. |
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