Power Supply issue on a G5 Power Mac

[Rockyricky]

I have a Power Mac G5 (2GHZ, 160 Gig HD, 2x512 MB Simpletech 3200 RAM, 2x256 MB Samsung 3200 RAM - Serial Number starting: XB347).

So Monday, I decided to open up the box and take a look at the RAM inside in anticipation of putting more in there. I actually took one of the Samsungs out to take a look and then put it back in the machine. Closed up the box, turned the power back on and ever since then when I turn on the power I get NO video, no chime, just the white LED light come on and going off about every 4 seconds, both LED lights on my 23-inch Cinema Display and on the front of the actual computer itself. The after a few minutes of the computer being on, the fans start up progressively getting louder and louder until I turn the machine off. Can't open the drive to boot from a disc either. Up until now, the computer has been fine, although I must admit I don't recall hearing the chime when I have started my G5 for a little while now. I just figured it was some preference I might have accidently altered so I thought nothing of it.

So far, I have been reading various boards on the internet, as well as troubleshooting docs on the Mac website. I went out and boaught new Corsair RAM (1 Gig x 2). I took the other RAM out and put the Corsair in. Didn't fix it. I went to Radioshack and bought a new PRAM battery. Put that in. Didn't help. Have hit the SMU button. Reset the PRAM per Apple. Nothing. So I called Apple support yesterday and the guy told me that based on his translation of how the LED light was behaving (one flash every four seconds) that it was a power supply issue. My question is, as I am trying to self diagnose and narrow down the problem, does this sound like what is going on? That I have a power supply failure? And if so, is it only solved by taking it into the Apple shop? Can I fix this myself...or at least further confirm that this is indeed the problem I am having? I have been reading on the net that many of the G5 Power Macs have had power supply issues so it sounds feasable that this may be what I am dealing with.

Thanks in advance for reading and for any advice you might be able to give.

[trevor]

I would first make absolutely sure that the RAM is seated properly. If it's not quite all the way seated, it could cause an inability to boot.

It seems unlikely (although not out of the question) that you coincidentally got a power supply issue immediately after removing RAM, so I'd first concentrate on the RAM.

Trevor

[Rockyricky]

Thanks, Trevor.

I think tonight I will add the old RAM back into it and I will check this seating of the RAM currently in the box, as well as the seating of some other components. I was really hoping to have a more definite identification of what the LED flashing at 4 second increments might be able to reveal. Like I said before, the Apple Phone Tech thought it was a Power Supply issue. Not so sure. However, he seemed pretty confident. Of course, he was in India...and I'm not sure that his response is reliable seeing as how he was having difficulty understanding what I was explaining to him.

I'm just hoping more so that I didn't zap something when I was in there that first time. I 've been reading though that you really have to gorilla around inside to cause damage like that...which I wasn't. I blew/very gently wiped some of the dust out of there, but not to the point it would cause any damage.

[Rockyricky]

GUESS WHAT?????? I feel a little like a heel, but am elated. Trevor, you were exactly right. In my obsession with getting into the computer with "kid gloves", I wasn't pushing hard enough on the DDR SIMM Chips to properly secure them into the slots. The side clamps should actually click on their own into place to secure the chips if you have fully pushed them in correctly. I was not doing this.

So THANK YOU, THANK YOU, THANK YOU, Trevor. This is what makes forum boards like this so great. ENLIGHTENMENT. Trevor, as an example, provided a much cheaper solution to spending god knows what on a power supply replacement I obviously didn't need.

Lesson is: Do Internet research first before spending money on Computer Support or taking your whole rig down to the store. You might just find an answer on these boards.

Thanks again.

[iMovieStar]

My PMG5 is picky like that as well, when I touch the RAM it does the same, I have to reset the PMU to get it to boot again.