Is my Imac ok?

I have an Imac g5 in white, (non intel and no i sight). Anyway, its been kinda flakey over recent years, the HD packed in, so Im running off an ext. hard drive. However, more recently it seemed to give up totally, and when i tried to turn it on, it displayed the screen very weirdly with odd lines and stuff (not dead pixels) and it would just sort of kernal panic and that would be it. So I had to use a super slow g3 power mac (400 mhz was torture) and today I had some spare time and decided to see what would happen to the imac when it plugs in.. and what do I know.. it works like a dream.. no problems at all.. which is odd as I though my graphics card had melted or something haha. Anyway, im just wondering if anyone else has had this kinda issue.. and if its gonna strike back on me, coz I really DO NOT want to go back to a 400 mhz computer Oh and also, is there anyway I can run dual monitors on my Imac? It doesn't seem to have any vga output.. and the monitor output I think it does have looks rather odd.. I haven't seen it before.. Thanks, harry.

G'day and welcome to the forums from one Harry to another.

Sounds like a failing logic board alas. Do you have the original discs which came with the iMac? if so run Apple Hardware Test which diagnosis logic board and graphics.

I had the same machine. It too started to behave strangely. It would switch itself off for no particular reason and without warning. On rebooting it would run ok for a few weeks and then switch off again. Eventually it died on me after exhibiting strange graphic displays.

I let a friend, who works for the local Apple Service Center, have a look at it and after running diagnostic tests, he located a faulty logic board. I had it repaced (with a 90 day limited warranty from Apple) and the machine ran faultlessly for nearly a year when it started playing up again resulting from a faulty PSU.

I considered I'd had my money's worth out of my faithful G5 so sold it for spares on ebay (apart from the hard drive) and bought a new one.

These machines don't run for ever and the time comes when they have to be replaced with a newer incarnation.