It's possible, but not likely unless you're using a particularly shitty PSU. Power supplies usually have at least some over-current protection and will just shut down if they encounter a dead short.

The cache chips and motherboard, OTOH, probably didn't fare so well.

psu should last.
put cache back in proper position, if they run hot you know there dead.
or if ram errors occur.

rgart wrote:

Can putting your cache chips around the wrong way (reversed polarity) damage your PSU?

Damage to the cache and/or chipset is usually time-dependent. For how long was the system powered up with the cache inserted backwards?

Yeah I thought so......

Quite a while....about 10 seconds.....

Im guessing the cache is dead ...it was pretty hot.

However motherboard and cpu are both still perfect.

PSU died badly. Coincidence or related? I think related.

If I try and power up with that power supply now large sparks fly and the house safety switch triggers 😜

House safety switch = RCD? Then its not related.

I've had a few bad cache pieces which would immediately get pretty darn hot. At 10 s, the motherboard and PSU survived. I have also inadvertantly put good cache in backwards once for less than 10 s. In that case, the cache was OK, but the motherboard had some stability issues afterwards. In every case the PSU was fine. You best test out your cache and motherboard to see if they are OK on a working PSU.

I'm not sure what went wrong with your PSU, but it sounds like your mains HOT and NEUTRAL are getting shorted inside the PSU, or at the PSU's on/off switch.

sparks shouldnt occur.
maybe the diode bridge or some capacitors broken.

what a sucky psu if it cant cope with some higher current.
get a 250w atx supply and remove the atx wiring and put the at wires in.

Is there anything I can do to repair the PSU or should I just ditch it and replace?

you could repair it but it takes a lot of time and de-soldering and measuring.
do you have a multimeter? and solder iron, and a other dead psu for parts?

ditching would be a good option or lay it to the side for later.
do you have any other good at supply?