iMac G5 (iSight) RAM Problem

[tayloralmond]

Hello All,

I recently picked up an iMac G5 (iSight) and just installed a 2GB stick of DDR2. Before installing the new RAM, I booted the computer and made sure the internal RAM (512MB) and the stock RAM (1GB) were working. Now that I've installed the new 2GB stick, my internal RAM is showing empty in system profiler and only shows the 2GB stick. Any ideas?

 

[VanneDC]

boots no worries?? hmm, in that case id pull both ram sticks swap em round/re-insert and make sure the slots are clean and give that a shot..

as per http://support.apple.com/kb/sp40 it supports 2.5gb...

trippy...

 

[tayloralmond]

Yeah, it's a weird problem. FYI, when I said "internal RAM," I meant RAM that is soldered to the logicboard and cannot be removed. Also, iSight G5's only have one RAM slot (which I placed a 2GB stick in). I'm 100% sure this iMac can support 2.5GB RAM (2GB stick and 512MB on the logicboard) so I don't know why it's ignoring its own logicboard RAM. Hopefully someone on here will have the answer.

 

[VanneDC]

does the internal show back up if you replug the 1gb stick in?

 

[MacHamster68]

does the internal ram show on its own?

Reset SMU ( and notice the important bit unlike the intels you need to press the power button at the same time as you plug in the power cable)


Resetting the SMU can resolve some computer issues such as not starting up, not displaying video, sleep issues, fan noise issues, and so on. If your computer still exhibits these types of issues even after you've restarted the computer, try resetting the SMU. To reset the SMU on one of these iMacs:

Turn off the computer by choosing Shut Down from the Apple menu, or by holding the power button until the computer turns off.
Unplug all cables from the computer, including the power cord.
Wait 10 seconds.
Plug in the power cord while simultaneously pressing and holding the power button on the back of the computer.
Let go of the power button.
Press the power button once more to start up your iMac.

 

[tayloralmond]

Ok, so here's what I've done so far:


Removed 2GB stick and booted up. System Profiler shows 512MB RAM (the logicboard RAM)

Inserted 1GB stick and booted up. System Profiler shows 1.5GB RAM (logic board+1GB stick)

Re-inserted 2GB stick and booted up. System Profiler shows 2GB RAM (logic board RAM slot shows "Empty.")

I'm baffled.

 

[tayloralmond]

Now out of nowhere the screen locked up. After restart I get the 3 bleeps of death. Replaced the ram and removed it dozens of times. Guessing I'm screwed.

 

[goMac]

Now out of nowhere the screen locked up. After restart I get the 3 bleeps of death. Replaced the ram and removed it dozens of times. Guessing I'm screwed.

Sounds like the 2 gig chip you bought could be bad.

 

[MacHamster68]

Apple states only as a requirement

PC2-4200
unbuffered
nonparity
240-pin
533 MHz
DDR2 SDRAM

but not the other things like latency and voltage and such

and Mac's always had been fussy when it came to Ram

a reason why i only get ram from crucial , as you can just send it back if they did recommended the ram on their site , but its not working in your Mac

for the isight iMac crucial recommends :

for the isight 17":

Part Number: CT518444
Module Size: 2GB
Package: 240-pin DIMM
Feature: DDR2 PC2-5300
Specs: DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64 •


and for the isight 20":

Part Number: CT518445
Module Size: 2GB
Package: 240-pin DIMM
Feature: DDR2 PC2-5300
Specs: DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64 •

why a different part number i dont know , for at first glance the same sort of ram, the PC2 5300 doesn't matter as its backwards compatible most of the time with PC2 4200 , just not at every manufacturer makes it backwards compatible