Does anyone know somewhere I can buy a replacement PSU for an old HP Pavilion Desktop (7870)?

It has to be an HP one and not a generic one because they are a different shape

Your best bet is ebay, HP hardware is a ight pain to get hold of!

can you put up a pic of the psu - i may be able to help......

The psu on my HP Pavilion packed up recently & I got one from the local PC shop (NOT PC World!). It's just a P III compatible generic but it fitted without any problems. £17.00 IIRC.

i own a little pc shop, put up a pic and i should be able to sort you out for a few beer tokens

It won't be generic if it is the HP type that sits above the proccessor, some also have an extractor duct going down to the processor.

I actually have an HP power pack but the PC it is in will be in use for a few more months

Easyway round it to stick the board in a standard case most ATX format cases will take HP boards.