Yeah that wasn't the case on mine, even when using a board which requires -5V the line is still deadgot an update so on several of the -5 lists of compatible games they have combatribes listed as having no sound if your -5 line is not working. A buddy let me borrow his combatribes pcb i plugged it in and have sound!! Also checked the -5v line as i raised and lowered the volume on the pcb and it registered an increase of negative voltage on my multimeter so it went from the .008 to nearly half a volt at .488. Im starting to suspect that this psu does not put out -5v unless it has a load on the -5v and at that point it only provides whats needed just as it was suggested earlier by Frank this makes sense as all psu ive adjusted in the past the +5v and -5 show matching voltages and adjustment since they have the same source. That's why it was strange to me that my +5v was fine usually from what ive seen if theres a problem with +5 you will have a problem with -5 thanks for all the help guys!!
Those lists are incredibly short. If I had to go by the boards I've owned it would be 3 times longer.found the wiki about what games use -5 volts i believe this is a partial list but helps alot funny it mentions astro city psu right of the bat must be a common issue
Also here is another useful thread i found on another forum
Thanks for all the help guys i will try to get ahold of another version of the astro city psu and test will report my findings!!
You got a multimeter? if you are going to open it up check the pot resistance, according to the circuit diagram it should be 1K. Check that and go from there.Have an Astro City PSU with what seems to be a faulty pot on the +5v adjustment. It's sitting dead still, on the higher end (but not burnout levels) on the 5v without any movement on the multimeter when I max the pot high and low.
Anyone here ever needed theirs replaced? Is this a common problem on these PSU? Wondering if I should send it off for repair, or attempt to change out the pot myself.