Powermac G5 boots up yet not?

[TechnoCrunch]

Hi everyone and this problem has been bugging me the whole day!
I even spent 4 hours of my day just to fix this.
Now lets get to the problem, my problem is that my Powermac G5 DP 2.0GHZ June 2004 boots up and the fans do their normal thing of reving up then down, after that the dvd drive reads my Mac os x Tiger disc for a while then it stops then the fans just speed up and up until its like a prop plane. I have taking the machine apart expect to the the cpu as the little pin I can't get out so the cpus are a no go for now. I have taken out all the ram and tested them all and I use a ADC connector for my monitor as I got it with the Powermac G5.
I got this $40 as it was a good deal please help I don't want this in the skip!
Also the power led only turns on when I press the power button down and there is only 2 leds the red led and power led.

 

[TechnoCrunch]

Please everyone I really need your help I got the cpu cover off but not the heatsinks.

 

[Zotaccian]

Well, it could the logic board solder failure, relatively common with PowerMac G5's because of the high temperatures of the U3 chipset. Some people have gotten the machine to boot if they heat the backside of the chipset (between memory slots) with a hair dryer for a while. Temporary fix of course, but if it works then you know it is definetely a solder failure.

G5 cpus may also fail.

Because the machine powers on I dunno if it could be the power supply, my guess is that it is not.

 

[TechnoCrunch]

I might try to reflow the soldering but it booted up yesterday morning to a blinking folder so it couldn't be a logic board failure right?

 

[Zotaccian]

Yes, many laptops also suffer from same type of failures and they may occasionally boot just fine and even work fine until they are powered off. Usually it requires several power on / power off cycles until the machine finally boots (the chip/solder heats -> solder expands -> sufficient connection is created)

 

[TechnoCrunch]

I'm just going to boot it up just to check before I do anything thing to it as it been doing this to me since I got it 2 days ago but for $40 won't kill me right? 😉

 

[TechnoCrunch]

Ok I booted it up and got no power light unless I hold it and my apple cinema display light doesn't stay on so what could it be instead of a logic board failure as it responds to me taking out the air deflector perfectly.

 

[TechnoCrunch]

Is there a way to reflow the soldering without removing the processors as I don't have the tool to take them off.

 

[Zotaccian]

You will need to remove entire motherboard to reflow and you should have proper equipment for the reflow. Some people use regular oven etc. but none of those kind of "tricks" are as good as professional reflowing station, as expected.

Price that companies charge for reflow is very likely too high for it to make sense for that machine.

 

[128keaton]

You will need to remove entire motherboard to reflow and you should have proper equipment for the reflow. Some people use regular oven etc. but none of those kind of "tricks" are as good as professional reflowing station, as expected.

Price that companies charge for reflow is very likely too high for it to make sense for that machine.

Agreed. On the PLUS side, the oven method works well. I pulled an Alu iMac C2D off the curb with a dead GFX card, i.e lines and wouldn't boot fully due to it. I took it home, removed the card, and baked it for ten minutes at 400 degrees F, let it rest, and repeated the baking of the card. After a year, its still going strong, the mac now has a whopping 5Gb of RAM, and soon a 500GB 7200 RPM HDD. It runs games like Minecraft, Robocraft, and Garry's mod just fine.