Dead Mac G5 question

[OldRoy]

I'm very much not a Mac person (despite having been an early-ish adopter in 1986/7) however I have a friend who has a Mac G5. He's very strapped for cash - young family/recession - and I'd like to help if I can. His Mac, he tells me, won't boot - or at least will very rarely boot: "it's just dead!". I believe it's not even displaying BIOS info. Apparently there's a live power supply whose fan is working and the power status light still comes on. I'm planning to take a quick look inside it for him and maybe put a meter on the PS output. I was wondering if anyone knows any "typical" faults I could look for?

My assumption is that relocating a few connectors is usually a good idea and also checking that the power supply is delivering the correct voltages. What are these for a Mac these days? +/- 5v? And are there still diagnostic chimes on start up?

Assuming it's a lost cause he'd need to recover some data files from the HD. I assume they're SATA these days and that my USB docking cradle could be used. If so, do we still have the old problem of Mac resource/data forks meaning that the files are castrated when copied onto a PC's NTFS drive?

Suggestions appreciated.
Roy

[francois]

I'm not a hardware guy but have you tried to look for PowerMac G5 repair guides on iFixit.com. Guides are free and you can purchase replacement parts for a large variety of Macs.

[Chris Gahran]

Could be the PRAM battery needs to be replaced. If that battery is dead the computer will not boot. It's a 5-10 dollar battery that should be changed every 4-5 years.

[OldRoy]

Thanks for the suggestions so far. I'd forgotten about the P-RAM, thankfully. "Zapping the PRAM" used to be one of the regular requirements of early Macs. Now where did I put my Hypercard floppies?
I'll try the PRAM battery fix first, then if necessary take a look at some technical data.
Roy

[RobSaecker]

The first question I'd ask is if it makes any startup chime(s), and if so, what. If it's making anything other than the single "bong", then it's indicating a hardware failure. If it's not making any sounds at all, but lights indicate it has power, then an SMU reset might work, rather than the PRAM reset. SMU reset varies by model, so you'll need to look up the procedure for that model.

[francois]

The first question I'd ask is if it makes any startup chime(s), and if so, what. If it's making anything other than the single "bong", then it's indicating a hardware failure. If it's not making any sounds at all, but lights indicate it has power, then an SMU reset might work, rather than the PRAM reset. SMU reset varies by model, so you'll need to look up the procedure for that model.

Good suggestion! Note that one needs to open the case to gain access to SMU reset button it's not like PRAM reset.

[jonathan.lipkin]

You might also want to try resettig the PMU

http://support.apple.com/kb/HT1939

Sometimes fixes power-on problems

[RobSaecker]

Just so there's no confusion, SMU = PMU. Apple has changed their terminology a few times; on the Intel Macs it's called the SMC.

[carloalberto]

Also. Pull out the memory module cards, remove all the memory DIMMs and insert only enough to startup. They must be inserted in in pairs to work and must be exactly matched (both same capacity and speed). Depending on the age of the G5 it may have a physical reset button on the motherboard that you have to press and hold for 10 seconds to reset the SMU. Some models have no switch and those you just shut down and unplug the power cord for a minute.