04-20-2011, 05:36 PM

I went to check out what kind of RAM I have in my G5, and it seemed as if one wasn't seated properly, so I took them out and reseated them all. Now When I boot up, the motherboard has a red light on it, and the light above the power button blinks twice. At this point, I have reseated them all 3x, and it's still happening. What's going on?

04-20-2011, 05:59 PM

The blinking light indicates failed or improperly fitted memory. G5's can be fussy about matched pairs of memory. If all else fails and you have the original install discs, run Apple Hardware Test if you can get it top boot from the disc, which checks out the memory modules.

04-20-2011, 06:01 PM

now how would i boot onto the hardware discs since i can't get the computer to show the apple logo?

04-28-2011, 09:22 PM

Ok, thought I would give an update to the situation. I went into work, and borrowed 4 sticks of 512MB RAM, and it turns out that with them in, it will boot just fine. So problem solved in terms of that, but herein lies another issue, the computer is only reading 1.5GB, not 2 like it should. Does this mean that the slots could be working at half capacity, or maybe the motherboard battery is dead? I'm asking about the battery because when I booted it up, an error came up saying the time has been reset back to a really old date.

04-28-2011, 10:28 PM

You probably need to change the PRAM battery. It's likely that's what is causing the memory to not be read properly and of course the system time gets reset on every boot up. Here's a LINK where you can buy a new PRAM battery.

04-28-2011, 10:30 PM

Ok good, at least it's nothing too expensive. Thanks for the link

05-04-2011, 07:41 PM

Originally Posted by chscag

You probably need to change the PRAM battery. It's likely that's what is causing the memory to not be read properly and of course the system time gets reset on every boot up. Here's a LINK where you can buy a new PRAM battery.

You know what, the computer's time is back to normal now, it's not resetting itself anymore, but the full amount of installed RAM still isn't being recognized. So there are 4 512 sticks installed, the first 2 slots are recognizing the full 512s fine, but the other 2 slots are only recognizing half of each stick installed. Could this PRAM battery be doing this?

05-04-2011, 07:51 PM

Here's a screenshot of what it's reading:



Now the only difference with the first 2 slots are one is a no name company, and the other is a Samsung, like the other 2 are.

05-04-2011, 08:23 PM

Not single sided by chance the fiust two, or high density PC memory instead of Mac compatible low density? G5's are very fussy about Mac compatible low density memory.

05-04-2011, 08:36 PM

Yea I really have no clue about either question. From what it looks like, all are double sided though. I would like to purchase 4Gbs for the machine, but this is worrying me about going and spending the $200 on the kit.

05-04-2011, 10:56 PM

It looks like the first two sticks are high density modules. Those are not compatible with Macs and will usually give a wrong reading. If you can exchange them for the same type you have in J13 and J14 you'll get the full amount. If you already put in a new PRAM battery, it should be reporting the correct time (which it is) and the amount of memory that the system sees.

05-04-2011, 11:10 PM

You should not have to pay that much. If you have the Dual Core, and we are not sure about the model, OWC offers 2 x 1GB at a little over $50.00. You want 4GB so get 4 x 1GB modules. Why? If you purchased 2x2GB and one fails, and you need matched pair, no boot up.

What memory and graphics does the G5 run - that will help with the model?


OWC OWC42DDR2PAIR2G 2.0GB Matched Pair (1GB modules... in stock at OWC