How do I discharge the capacitors in my PS audio P20 ?


I need to reconnect a wire inside my P20 regenerator but before I do I want to make sure the capacitors have all discharged. With a Multi Meter how is this done?

Thanks, Mike

hiendmmoe

Power down. Unplug from the wall, turn power switch back on. This should drain any residual charge left on any power supply caps.

No. That will recharge the capacitors.

Cleeds, et. al. - 

I don't know if there is any standby power battery in the described device, but if the unit has been unplugged from the wall, ANDS REMAINS UNPLUGGED, I am not sure where the power is coming from to recharge the capacitors when the power button on the device is pressed. Press and hold for a few seconds may be worthwhile. 

This procedure is standard practice to ensure that a computer system's PSU and other components are fully discharged before pulling circuit cards, drives, etc.  Also, since the user may not know the polarity of the electrolytics in question, they should watch carefully for ANY change in readings on a test multimeter - either up or down scale - which would indicate that some residual charge remains in that part of the system.

Finally, testing should be done on a DC range similar to the rated voltage indicated on the side of the capacitor being tested.  More, and you may not notice any "twitch" of the needle, and less may result in damaging the test instrument or device being tested.  Also, given the internal workings of the test device and the voltages involved, there may be only a momentary indication of residual charge, not a steady-state reading.  

@frankmc195 If I had to wait 24 hours every time I needed to work on a tube amp...

Erik has the correct answer. Then after the wait ...

noromance... this is do as I suggest not as I do. I have a 12 guage wire open at both ends taped to two round dowels and I just touch them to each pole. You do this at your own risk as the capacitor may go away. I haven't had it happen but it can. Now if I had suggested what I do, I would have 30 on this blog telling me how dumb I was to suggest such a thing.

How will the capacitors be recharged with no power applied to unit. I worked as a audio repair tech for 40 years and it always worked to drain off power supply charges