Peter Chou USP-11-150X shuts down

gobsgraham

Member
Joined
Mar 26, 2009
Messages
649
Reaction score
17
Location
AB, Canada
Hi Everyone,

I have this Peter Chou PS running a Big Buck Hunter. When I boot the game I get a high voltage warning and measure it at 5.85. The problem is when I try to turn the voltage down with the dial, the PS shuts down completely. The caps all look okay in it and it isn't the R6/R11 dead that won't allow it to start. Could it be that the Buck Hunter is just not drawing enough current to keep the +5V on so it is shutting down?

THanks
 
The adjustment pot itself could be flakey, I had one like that. Try it with just a dummy load, no game board. I use a car light bulb and some clip leads, but a big resistor would work. Work the pot back and forth, try to get it to go down to 5v.

Big Buck Hunter should draw more than enough to keep the supply happy.

-Ian
 
I have played with it on my desk and notice the same thing although I didn't have a load on it so I will have to do that.

With no load I can get it down to about 5.65 and then it cuts out.
 
I've noticed the adjustment pots go "scratchy" internally on these power supplies. I spray them out with volume control cleaner.

I would definitely test the electrolytic capacitors with an ESR meter to be sure they are indeed actually "good". A bad or marginal one in the feedback circuit (voltage monitoring) could cause it to shut down.
 
My ESR meter is at home but I will check them tonight. I will also check the pot to see if it is operating properly and will probably replace it to be safe.

Thanks for everyone's advice.
 
is this the large XT form kind? I had one of these in a Daytona USA do what Ken says, except the voltage like bottomed out entirely to 0.0.

almost like in addition to the pot being gunked up it's like it had cold solder and came out entirely right?
 
The voltage adjustment pot can get dirt in it and get "scratchy". This scratchiness can cause the power supply to shut down when adjusting the pot. I sprat it out with volume control cleaner then work the pot back and forth a few times (all while the machine is unplugged from the wall outlet). You'll probably need to readjust the +5 volts after doing this. Also, to keep the pot from getting dirty in the future, I remount it with the solder lugs pointing down. The factory had it mounted with the lugs pointing up allowing dirt to get into the pot.
 
Back
Top Bottom