Did coin lamps kill my power supply?

[XYXZYZ]

My cabinet had a switching power supply with some wires connected to the +12V line. Which includes the coin lamps, and I don't know what else, I think it just goes to the JAMMA harness. Since that supply won't work without a load, I ran a wire from the PC power supply's 12V line, and connected it to the set of wires on the cabinet's supply. (I disconnected them from the cabinet's power supply all together) So, I had the coin lamps working whenever the PC was on. In stead of shutting down, I put the PC in sleep mode when I'm not using it.

This morning I wake to the sound of firecrackers going off in my living room, it turns out the PC's power supply bit it. When I removed it, a blackened ceramic capacitor fell out, and after I opened it I found some burned resistors, a big one even broken in half! (I still can't figure out where that cap went) When it happened, the PC was in standby and the coin lamps were off. It'd been working just fine for a month.

Do you think my tying that 12V stuff to my PC's supply had anything to do with that, or perhaps keeping it in standby all the time, or was it just a flaky power supply? It was a 400W Leadman Powmax.

[SirPeale]

Was it new?

[DJ_Izumi]

Sometimes PSU's do just die.  Generally if they're over taxed they'll just brown out the rest of the system.  That is, if there wasn't enough power to go around, the system would have gone funky.

A cap probably just wore out and burst and took the whole thing with it.

[BobA]

When using an ATX type supply for a PS in arcade use the usual min usage is on the 5V line not the 12 V line.   It is possible that this is the cause of your supply failure if you did not have any 5v Load.

[Ken Layton]

Yes these power supplies must have a minimum load on the +5 volts line or the power supply will get damaged.