SO-DIMM DDR3RAM didn’t work iMac late 2009

[dannydagranny]

My iMac 21.5” late 2009 didn’t accept a SO-DIMM DDR3 PC12800 4 GB from Team Group, it only beepeed when I tried to power on. Why?

 

[nambuccaheadsau]

4 - 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM

Coz it is the wrong memory. Above is from Mactracker. Macs are very fussy about modules, especially older models. Crucial and OWC, both Mac specialists, recommended.

 

[dannydagranny]

So even if the RAM I bought was backward compatible with PC3-8500 1066MHz it’s a no no?

 

[nambuccaheadsau]

That is what the beeps told you.