I’ve been lucky enough recently to score a Keithley 2304 power supply off ebay for a measly $75. For those unfamiliar, these are high speed battery simulator units capable of measuring very low currents and also behaving like a battery and sinking current.
Today’s repair subject is a Fluke 8840A bench DMM that has some display troubles. It would work normally for a bit and then start fading out. A bit later it would come back and work again. The initial thought was that the display simply had too many run hours and is worn out. In that case a replacement is required and is not a very cheap solution. Continue reading