Granville-Phillips Micro Ion Gauge ATM Repair

The Micro Ion Gauge ATM is an awesome gauge that is extremely sensitive and reads from atmospheric pressure down to 1e-9 torr switching seamlessly through a range of 4 different vacuum gauges. It has an analog voltage output from 7volts down to 0.5v logarithmic to the pressure. This gauge had very bad noise issues, the voltage output moved with pressure change but was not useable due to the analog output swinging ~ +/- 0.25 volts multiple times per second.

The problem was found to be bad electrolytic caps, as expected. They exhibited high ESR, Low DC resistance, puffed up vent/tops, and electrolyte leakage on the PCB.

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