Repair knob on switching power supply?

scamp

Member
Joined
Jun 20, 2010
Messages
194
Reaction score
0
Location
New Jersey
I recently purchased a switching power supply and when I tried to adjust its output I noticed the "knob" wasn't doing anything when I turned it.

Is it worth fixing? Has anyone done this that can give me some clue on how to proceed?

Thanks!
 
How did you test the power supply to see if the knob was or was not doing anything?
 
I had my multimeter attached to ground anf +5v on the adapter board attached to the switching power supply (for my Tron)...

The meter read 35v! So I tried to turn the white knob to adjust the output, however the value wasn't really changing...

So I'm thinking that knob is messed up since it should enable me to adjust the output voltage.
 
You either had the meter connections on the wrong pins or the meter was set to something other than DC volts. 35v would instantly fry just about every chip in the game.

RJ
 
I had my multimeter attached to ground anf +5v on the adapter board attached to the switching power supply (for my Tron)...

The meter read 35v! So I tried to turn the white knob to adjust the output, however the value wasn't really changing...

So I'm thinking that knob is messed up since it should enable me to adjust the output voltage.
Did you have the power supply and adapter connected to the Tron machine, or were you trying to check the power supply without connecting it to your gameboard?

Switching power supplies only behave properly when loaded. This sort of strange behavior might be expected (and damaging to the PS) if you operate it with no load. You either need to connect it to your gameboard as load or get something like lightbulbs on there as an artificial load.
 
Yes I had it connected...it powered the game...I removed it though since I couldn't verify the correct voltage...

I can replace the batteries in my meter, but like I said when turning the knob I noticed no fluctuation in voltage which again leads me to think the knob is busted
 
As said - if you read 35V then you are measuring it wrong. If you really had 35v the board would be completely and utterly wrecked. As it ran the board you can be 100% sure that reading is not real, therefore you are not measuring what you think you are measuring, or your meter is set incorrectly/faulty/has seriously flat battery.
 
Yes I had it connected...it powered the game...I removed it though since I couldn't verify the correct voltage...
Your response is unclear. Typically an arcade-style switching power supply cannot operate properly and cannot generate a correct voltage with no load. If you're saying that you read +35v without anything connected then that makes sense; the power supply won't work properly when operated with no load and might do exactly that. Remeasure with the board connected.

If you're saying that you read +35v with the PCB connected and the game running then you have a broken multimeter or you're using it incorrectly.
 
Back
Top Bottom