imac G4 800MHz memory oddity

[GondolinOnMyMind]

All,

I'm trying to increase the max memory of this iMac. Currently there is a PC-133 256MB SIMM on the internal slot and 512MB SO-DIMM on outer slot.
The SIMM on the inside slot is currently single sided. All the other PC-133 SIMMs I do have are double sided, and those are NOT recognised at all.
So, is there an known issue with double-sided SIMMs and this iMac just wont work with those?

 

[GondolinOnMyMind]

Anybody got any thoughts on this? Do double sided SIMMs work in iMac G4?

 

[RepairManiac]

Every PC-133 512MB 168-pin DIMM I have in my known-good Mac stash are double-sided. Just upgraded an iMac G3 slotload with two of these 512MB's and it works just fine, so it should work fine with your iMac too. However, I know Apples can be picky or quirky at times. I ALWAYS reseat memory upgrades at least twice during initial install because of having known-good memory not working on the first attempt (I do this is on all models). Also make sure a "dust bunny" didn't get across a few of the pins, or other debris.

It's funny that the service manual doesn't really cover the memory upgrade for the internal factory DIMM except for this blurb:
"RAM expansion DIMMs for the iMac must be PC133 compliant and use SDRAM devices. If the user installs a DIMM that uses EDO or SGRAM devices, the computer will beep several times when the user attempts to restart the computer."

Are all the DIMMs you have the same make and manufacturer? if so, you will need to try another brand.