Behold, the culprits:
These two DDR2 modules once functioned perfectly in my 2007 A1226 MBP, but alas, no more. The "why" of it is something I can't understand.
It's not the RAM itself. I pulled the modules from a working Dell Inspiron 1545 which I had upgraded to serve a particular purpose (some standardized professional testing). That purpose having been served, and said Inspiron having developed certain faults which were not worth fixing, I retired it to recycling. But the memory was never a problem.
And that was also the case - I emphasize was - in my 2007 MBP, from which I originally pulled these modules for service in the Inspiron. Back in 2018 when I purchased that MBP, one of the first things I did was bump the RAM up to the max 6 GB. It ran like a top with nary a problem. But upon retiring the Inspiron and returning these modules to the MBP, the MBP wouldn't even POST. Just gave the flashing lights on startup, no bong, no fan spin, no nothing.
OK, I thought, something happened to the modules when I pulled them from the Inspiron. So I tested them in my 2008 iMac 8,1. All 6 GB registered, and everything worked fine. Alright then, maybe I didn't get them seated properly in the MBP, so I tried that again. Nope, just flashing lights again. OK, maybe I somehow damaged the MBP when I pulled its 4 GB of RAM out, and put the 6 GB back in...uh, nope. Booted right up with the 4 GB.
OK, says I, scratching my head...maybe I'm just remembering things wrong. Maybe this wasn't the 6 GB I had in there before. After all, the A1226 MBP takes PC2-5300, and these modules were PC2-6400...in my experience this should work, but who knows, computers can be picky. So, I take a good look around for a PC2-5300 4 GB module. I can't find one. Anyone who's shelled out the bucks for one of these knows they're not cheap, and knowing myself I can't see having something like that laying around when I had a beloved old Mac that could take advantage of it! And I sure don't remember buying one, and I usually do remember that stuff. The only 4 GB RAM module I had, besides the one in regular use in my iMac, was the one pictured above - and I just know I had that working in my MBP!
Or maybe I didn't....more head scratching...perhaps I'm losing my mind?? But then, I found proof that I did, in fact, have 6 GB of RAM working in that MBP. And that requires a 4 GB module. And the only one of those I possess (besides the one in the iMac) is the one you see pictured above.
I also tried the pictured RAM in a 2008 A1261 MBP I'm putting together from parts. The A1261, like the A1226, uses PC2-5300. I got the same result: lights flashing, nothing more. This is clearly a RAM problem, despite the fact that these PC2-6400 modules are known good. In my long experience, RAM modules from the same family, e.g., DDR2, should work in any machine that accepts RAM from that family. So, I should be able to use PC2-6400 in a PC2-5300 machine, because they're both PC2, i.e., DDR2. It's not the brand, or the size, either: I tried several 2 GB modules, alone and one at a time, from Samsung, Kingston, and Micron, respectively. Nothing. But the same brands and sizes in PC2-5300 all worked.
I'm just at a loss. I've found through some light web searching that there are other reports of MBPs not accepting faster RAM than they shipped with, even if said RAM is in the same family. But this is the first time I've experienced it, and darned if I can explain how it used to work, but now doesn't work, in the same machine, when there's nothing wrong with either the machine or the memory as far as I can tell.
These two DDR2 modules once functioned perfectly in my 2007 A1226 MBP, but alas, no more. The "why" of it is something I can't understand.
It's not the RAM itself. I pulled the modules from a working Dell Inspiron 1545 which I had upgraded to serve a particular purpose (some standardized professional testing). That purpose having been served, and said Inspiron having developed certain faults which were not worth fixing, I retired it to recycling. But the memory was never a problem.
And that was also the case - I emphasize was - in my 2007 MBP, from which I originally pulled these modules for service in the Inspiron. Back in 2018 when I purchased that MBP, one of the first things I did was bump the RAM up to the max 6 GB. It ran like a top with nary a problem. But upon retiring the Inspiron and returning these modules to the MBP, the MBP wouldn't even POST. Just gave the flashing lights on startup, no bong, no fan spin, no nothing.
OK, I thought, something happened to the modules when I pulled them from the Inspiron. So I tested them in my 2008 iMac 8,1. All 6 GB registered, and everything worked fine. Alright then, maybe I didn't get them seated properly in the MBP, so I tried that again. Nope, just flashing lights again. OK, maybe I somehow damaged the MBP when I pulled its 4 GB of RAM out, and put the 6 GB back in...uh, nope. Booted right up with the 4 GB.
OK, says I, scratching my head...maybe I'm just remembering things wrong. Maybe this wasn't the 6 GB I had in there before. After all, the A1226 MBP takes PC2-5300, and these modules were PC2-6400...in my experience this should work, but who knows, computers can be picky. So, I take a good look around for a PC2-5300 4 GB module. I can't find one. Anyone who's shelled out the bucks for one of these knows they're not cheap, and knowing myself I can't see having something like that laying around when I had a beloved old Mac that could take advantage of it! And I sure don't remember buying one, and I usually do remember that stuff. The only 4 GB RAM module I had, besides the one in regular use in my iMac, was the one pictured above - and I just know I had that working in my MBP!
Or maybe I didn't....more head scratching...perhaps I'm losing my mind?? But then, I found proof that I did, in fact, have 6 GB of RAM working in that MBP. And that requires a 4 GB module. And the only one of those I possess (besides the one in the iMac) is the one you see pictured above.
I also tried the pictured RAM in a 2008 A1261 MBP I'm putting together from parts. The A1261, like the A1226, uses PC2-5300. I got the same result: lights flashing, nothing more. This is clearly a RAM problem, despite the fact that these PC2-6400 modules are known good. In my long experience, RAM modules from the same family, e.g., DDR2, should work in any machine that accepts RAM from that family. So, I should be able to use PC2-6400 in a PC2-5300 machine, because they're both PC2, i.e., DDR2. It's not the brand, or the size, either: I tried several 2 GB modules, alone and one at a time, from Samsung, Kingston, and Micron, respectively. Nothing. But the same brands and sizes in PC2-5300 all worked.
I'm just at a loss. I've found through some light web searching that there are other reports of MBPs not accepting faster RAM than they shipped with, even if said RAM is in the same family. But this is the first time I've experienced it, and darned if I can explain how it used to work, but now doesn't work, in the same machine, when there's nothing wrong with either the machine or the memory as far as I can tell.
