Mac Plus only recognizing 2MB of a 4MB set

[jblang]

I'm trying to upgrade my Mac Plus from the stock 1MB of RAM to 4MB. I ordered a 4X1MB kit from MemoryMasters on eBay. Originally I ordered the wrong kind (3 chip parity), which I understand won't work in a Mac Plus, but they exchanged it for me with a set of non-parity 8 chip sticks. Unfortunately it is still only reporting 2MB in the About Finder dialog box (system 6.0.8). Any ideas why this would happen?

 

[jblang]

Hmm... I found this, which says I'm supposed to remove resistors to get it to recognize the full amount? Just looking for some confirmation that this works before I start ripping components off my motherboard.

Memory Upgrades: Mac Plus | Low End Mac

lowendmac.com

 

[jblang]

Markings on the motherboard seemed to confirm so I said YOLO and snipped one of the legs on R8 and pushed it to the side so hopefully I could solder it back if I need to go back to 1MB. Now it works! Wow, that's a new one for me!

 

[Phipli]

Hmm... I found this, which says I'm supposed to remove resistors to get it to recognize the full amount? Just looking for some confirmation that this works before I start ripping components off my motherboard.

Memory Upgrades: Mac Plus | Low End Mac

lowendmac.com

Yeah, same on the SE.

Snip one leg and bend it upwards slightly. Makes it easy to put back with a blob of solder, if you ever need to.

 

[Phipli]

Markings on the motherboard seemed to confirm so I said YOLO and snipped one of the legs on R8 and pushed it to the side so hopefully I could solder it back if I need to go back to 1MB. Now it works! Wow, that's a new one for me!

Yup, like that