G5 Dual 2.3Ghz sometimes not booting

[DBAlex]

As the title suggests a Dual 2.3ghz G5 I just picked up recently seems to randomly decide to not boot, the fans will whirr and the power LED stays on but it doesn’t boot.

If I switch everything off and disconnect the power cord and wait a few minutes and retry it usually boots but still not always.

I’ve replaced the CR2032 battery on the logic board and reseated the RAM but that doesn’t seem to have fixed it.

I have a Samsung 870 Evo SSD set up as startup disk on SATA port 2, doesn’t seem to help if I set it as primary though.

Any help is appreciated.

I also have a Dual 2.7ghz that froze playing Doom 3 which I’m going to have to sort too, that one is probably a topic for a different thread though, the power LED comes on but then goes out but the Mac stays on just no video out USB etc.

 

[Dronecatcher]

As the title suggests a Dual 2.3ghz G5 I just picked up recently seems to randomly decide to not boot, the fans will whirr and the power LED stays on but it doesn’t boot.

Look up "resetting the SMU on a Power Mac G5" - I had this same problem and the reset fixed it.

 

[DBAlex]

Look up "resetting the SMU on a Power Mac G5" - I had this same problem and the reset fixed it.

Thanks for the advice. Did that tonight but still not booting consistently. Tried resetting the SMU by both removing the power, battery and pressing the button and also leaving it plugged in and pressing the button but no luck on either.

I thought I’d cracked it by removing the SSD but that turned out just to be a coincidence.

If it makes any difference when the computer has been off overnight it won’t power on and stay on until it’s been power cycled a few times. Unfortunately in my eyes it’s looking like a power supply issue?

 

[srp]

Do you get a boot chime? Do the LEDs change state and flash at all? The flash codes would help a lot with indicating WHERE the problem is... the dual 2.3 is liquid cooled, right? If it is liquid cooled, check the LCS for signs of leakage/inspect the CPU cards for signs of corrosion.

If you get a boot chime with no video, then I'd say it's the GPU.

If you get no boot chime and 3 LED flashes then it could be the U3 memory controller issue - you should apply pressure to the memory controller on boot or try the reflow technique.

If you get no boot chime and NO LED flashes but the device does eventually boot after trying repeatedly, I'd wager that's a logic board, CPU or power supply issue (in order of likelihood)

If you get no boot chime and NO LED flashes and the device doesn't boot at all (just a fan spin) I'd probably bet on the power supply being bad.

This might be helpful for you: https://github.com/Wooty-B/Power_Mac_G5_Guide/blob/main/Guide-codes.md

 

[Matias_]

Dual 2.3 GHz were never liquid cooled, only 2.5 GHz and up. CR2032 battery implies a late 2005 PCIe model. Those can have PSU issues but I'm not sure, hard to tell.

 

[DBAlex]

Do you get a boot chime? Do the LEDs change state and flash at all? The flash codes would help a lot with indicating WHERE the problem is... the dual 2.3 is liquid cooled, right? If it is liquid cooled, check the LCS for signs of leakage/inspect the CPU cards for signs of corrosion.

If you get a boot chime with no video, then I'd say it's the GPU.

If you get no boot chime and 3 LED flashes then it could be the U3 memory controller issue - you should apply pressure to the memory controller on boot or try the reflow technique.

If you get no boot chime and NO LED flashes but the device does eventually boot after trying repeatedly, I'd wager that's a logic board, CPU or power supply issue (in order of likelihood)

If you get no boot chime and NO LED flashes and the device doesn't boot at all (just a fan spin) I'd probably bet on the power supply being bad.

This might be helpful for you: https://github.com/Wooty-B/Power_Mac_G5_Guide/blob/main/Guide-codes.md

Dual 2.3 GHz were never liquid cooled, only 2.5 GHz and up. CR2032 battery implies a late 2005 PCIe model. Those can have PSU issues but I'm not sure, hard to tell.

Thanks for the help both. I still suspect a Power Supply problem however I have managed to get it to boot more consistently now.

I reset the PRAM using Command + Option + P + R and I seem to be getting a chime every time I boot now.

To be honest I thought I already did this yesterday by doing it via Open Firmware but obviously that hadn't solved the problem.

There is a separate problem now however, I seem to have lost a 2GB stick of RAM (in the system but not showing in System Profiler) and the Hard Drive doesn't seem to be mounting. But at least the SSD is consistently being seen and I get a consistent boot.

Again appreciate all of the help. I just hope it doesn't go south again and fingers crossed I can get the RAM and SATA issues sorted too.

 

[DBAlex]

Well, quick update, booted up straight away with a healthy chime after being off for over 24 hours tonight.

I never knew PRAM could cause so many problems!

Again appreciate all the help and advice everyone has given.

Next on the agenda is to try and clean the machine with an air compressor tomorrow, hopefully I can get the fan at the back of the media bay cleaned somewhat, enough to make it a bit less noisy anyway.

 

[DBAlex]

Further update, successfully managed to clean the whole system, even managed to remove the blower fan at the top of the case behind the media bay fan. For anyone for future reference, you need to remove the 2 screws holding in the media bay fan first and then twist that and remove it.

Then the blower fan is connected to 2 "posts" (don't know a better way to describe it) one in the top left hand corner and one in the bottom right and if you keep pulling on it eventually it will come off (don't worry you won't break it).

It was absolutely filthy! I've managed to clean it as best I can but some of the dirt was almost ground into the plastic and even with a toothbrush could not be removed. Was considering soaking it completely but didn't want to end up breaking it.

I've re-assembled everything and the system is much quieter but the blower fan is still noisy! Albeit way less noisy than before, it now has a quieter tick-tick noise but it's still there.

Maybe a future project is replace it completely. I've narrowed it down to definitely being that as (not recommended) but I disconnected it from the logic board for a few seconds with the system running.

Someone with more experience could probably remove the actual blower fan from it's housing and add some oil or grease to the bearing as I believe that is probably where the noise is coming from.

Overall though i'm fairly satisfied, also the 8GB of RAM is now back and with all of the cleaning i've discovered that the system actually has an Airport Extreme card that wasn't working previously so now to need for my Belkin Wireless G USB Adapter!