Power Mac G5 Power Supply Failed/Burned

[Mike Richardson]

My Power Mac G5's power supply failed. One of the brown pillow-shaped resistors started burning up as I was using it. The one next to it burned a little bit as well.

It looks like an easy fix though. I've got it all disassembled, tomorrow I just need to buy two new resistors and solder them on and it should be good to go.

I got the G5 on August 8th, 2004. Funny how problems seem to occur right after purchase anniversaries. :/

Still I'd like to get a couple of more years out of this as my main Mac. So far it's been great and it's still fast and does all I need to do.

 

[tomlee59]

While I hope that your cheerful optimism proves out, it may turn out that the burned resistors are a symptom, not a cause. Resistors are pretty hardy, and not generally given to spontaneous acts of suicide. Murder is much more common.

You may have additional sleuthing ahead of you, I'm afraid.

 

[Mike Richardson]

While I hope that your cheerful optimism proves out, it may turn out that the burned resistors are a symptom, not a cause. Resistors are pretty hardy, and not generally given to spontaneous acts of suicide. Murder is much more common.
You may have additional sleuthing ahead of you, I'm afraid.

I'll try soldering on the new resistors, and running it with the case off for a while to see if they burn out again. However, I can't afford much downtime as it is my primary Mac which is set up for me to do all of my work on.

I have another G5 that just sits in my bedroom collecting dust - a Dual Core 2.3 GHz model with PCI Express, that I got for $150 - it freezes up about 10 minutes after you use it, every time, guaranteed. I wonder if it has a suitable power supply. Or perhaps it's power supply is also bad, sending a wrong voltage or some such, which freezes up the Mac.

 

[Cory5412]

Luckily you've got that macbookpro, and USB/SATA adapters so you c an get your data off of the G5 are not that expensive.

 

[coius]

I have another G5 that just sits in my bedroom collecting dust - a Dual Core 2.3 GHz model with PCI Express, that I got for $150 - it freezes up about 10 minutes after you use it, every time, guaranteed. I wonder if it has a suitable power supply. Or perhaps it's power supply is also bad, sending a wrong voltage or some such, which freezes up the Mac.

have you tried taking it apart and cleaning out the dust in it? may be an issue. Also, does the model use the coolant? Try checking the level. it may have either evaporated or leaked out

 

[Mike Richardson]

It was not a resistor that burned - it was a capacitor. My friend mis-identified it.

 

[Christopher]

So your able to fix it?

BTW that quicksilver rocks! Thanks again.

 

[Mike Richardson]

I am typing this on the G5. After about three hours today, and an hour yesterday, plus two hours at Fry's (They only had one capacitor. The guy had to find the other one. I also had lunch there), it's fixed. No malignant odors so far.

I'm just glad my awful soldering skills didn't trash the whole power supply. I guess I'm getting better.

The culprit was one 400V, 0.1 microfarad, Mylar/Film capacitor (it looks like a brown pillow). It started burning out on it's right side. Some of this spilled on another capacitor of the same type, wounding it as well. Both have been replaced.

Assuming my repair job holds, I look forward to at least another year of service from this G5 before I get a Mac Pro.

 

[tomlee59]

Congrats on fixing it, Mike! Capacitors commit suicide more often than do resistors, so you likely have truly fixed the problem, and can look forward to it working for a good long time.