Should I change PSU or ge a new computer?

Dear All,

I own a mid 2007 iMac (7,1 - EMC 2133) that I upgraded to 4 gigs of RAM and SSD two years ago ( running on OS X 10.11.6 since then).

I’ve been using this machine for almost 14 years, mainly for web browsing, office apps, amateur web development and light image processing (creating image composites not exceeding the size of A4 paper).Yesterday, it suddenly died with a flash and a thunder (literally, no power outage otherwise; fortunately I successfully retrieved its ssd - works fine through a SATA to usb3 adapter). I opened it to testify that none of the four LEDs light up (of course nothing happens when pressing power btn). Measured PSU with multimeter: all to 0 V even though receiving 240V.

My question now: should I invest into buying (through ebay) a new PSU? Or should I buy a new computer? [Please consider that I have not ruled out that other systems are ok] What are the chances that another component fails (given the wear)?

Thank in advance!