HP / Agilent / Keysight 34401A Odd 4W resistance measurement fix

Описание: Quick fix for odd behaviour of my multimeter in 4W resistance mode. The problem was traced back to solder joints that weren't cleaned. After cleaning the meter performs normally again.
I never opened this meter for as long as I had it, until the day of the repair. It looks like somebody has done a repair after calibration since calibration seals have always been absent.