The repair itself, it is not particularly noteworthy, because this supply has served me well in the last years, in fact, it had been switched “ON” all the time to power an experimental setup.
The initial repair of this supply has been documented before, and on the pictures there it is quite visible that this supply had damaged binding posts. Seems that the prior user dropped it on the front panel.
Now the noteworthy facts, a kind reader of this blog, an American fellow, had a few of these posts at hand, from a HP plotter. He kindly sent them to me, free of charge!
So, as a result of the kindness of the reader, and the standardization of the parts HP used in their equipment, the power supply is now in better shape than ever before.
Did a few tests, like, checking ripple current at full load, and electrical safety – ground resistance, but all looking good.
Today, a package arrived, containing, a defective 6205C dual power supply. This model is capable of 0-20 V, at 0.6 Amps, or 0-40 V, at 0.3 Amps.
The ranges, as well as the meter indications (V or A, x1 or x10 scale) are selectable by two groups of pushbutton switches, and someone figured out earlier that the switches for the V2 output are defective….
… well, not quite. The switches work, but they don’t stay pushed in. A mechanical failure?
Fortunately, it is quite clear what had happened. Someone dropped the instrument, and the front panel was hit – bending it inwards, reducing the gap from the switches to the circuit board. With insufficient room to work, the switches appear inoperative.
To fix this, no soldering iron is needed, just a hammer, and a piece of wood, to get the front panel back in shape and aligned.
The front terminals are a bit damaged, but they work, and I will have a look around for a few spares (these are 1510-0091 binding post – let me know, if you have one around), or try to fix them by some custom-made red plastic inserts – this will have to wait for the next winter!