Question New RAM installed, computer starts, nothing shows on screen

[Zero1000]

Purchased RAM upgrade for OptiPlex 780. Im no computer guy, so I called a buddy who is, said to leave old RAM in and just plug in new RAM. Did that and computer started but nothing on screen. For shits and giggles I switched the positioning of the RAM and nothing happened also. He then had me remove the old RAM and put new RAM into the slots where old RAM was, nothing happened. I switched back to old RAM and computer fires up and works ( how I am able to write to you ). Any suggestions I can try? Thanks

 

[DavidM012]

Well it's downclocked hmm I suspected something like that so the final recourse is to see if 10600 ddr3 dimms will run at 666.67mhz. 8gb will seem to run a bit faster simply because windows has to use the swap file less.

Or the other consideration is that something's up with the Dell bios and it might still have to be 4x2gb 10600 dimms to get 8gb to run at the full 1333 mhz that the cpu core 2 duo 8400 datasheet says it supports. Rather than 2x4gb dimms.

What qvl ? A search of that throws up some discussions that they used some crucial dimms but I don't see a qvl

This thread contains some dead links to pages from Kingston or crucial

I doubt if anyone was using cpu-z then to see what speed the mem was running at. wait one of them said they had no idea why it was running at 533 rather than 1600mhz well that's 533 rather than 800mhz for 12800 dimms the cpu only supports max. 666.67 10600 dimms anyway.

Still says keep trying 12800 dimms pointlessly. Then they say use DELL dimms. Search for example, "dell part 8C7JC" will yield good results of our OEM memory. They says

Nothing on google shopping page tho. It's too outdated! If it's running at 533mhz and that's all it's going to do, $10 for 2 more 2x2gb of the original elipida dimms,

unless you're still game for trial and error with some 10600 dimms.

The guy who said

CT2KIT51264BA160B works perfectly was running at 533mhz! They were spending money to get 8gb-16gb in 4gb dimm configurations but didn't think it should run at 667/1333 as the manual states.

The way the dell guy says:

RE: Optiplex 780 - memory compatibility
Again, we only validate ours. We cannot speak to retail memory.

It's everyone else's fault says it all... lolly! There was some sort of problem getting it to run at ddr3 1333, the max the cpu supports, possibly.

 

[ARICH5]

Well it's downclocked hmm I suspected something like that so the final recourse is to see if 10600 ddr3 dimms will run at 666.67mhz. 8gb will seem to run a bit faster simply because windows has to use the swap file less.

Or the other consideration is that something's up with the Dell bios and it might still have to be 4x2gb 10600 dimms to get 8gb to run at the full 1333 mhz that the cpu core 2 duo 8400 datasheet says it supports. Rather than 2x4gb dimms.

What qvl ? A search of that throws up some discussions that they used some crucial dimms but I don't see a qvl

This thread contains some dead links to pages from Kingston or crucial

I doubt if anyone was using cpu-z then to see what speed the mem was running at. wait one of them said they had no idea why it was running at 533 rather than 1600mhz well that's 533 rather than 800mhz for 12800 dimms the cpu only supports max. 666.67 10600 dimms anyway.

Still says keep trying 12800 dimms pointlessly. Then they say use DELL dimms. Search for example, "dell part 8C7JC" will yield good results of our OEM memory. They says

Nothing on google shopping page tho. It's too outdated! If it's running at 533mhz and that's all it's going to do, $10 for 2 more 2x2gb of the original elipida dimms,

unless you're still game for trial and error with some 10600 dimms.

The guy who said

CT2KIT51264BA160B works perfectly was running at 533mhz! They were spending money to get 8gb-16gb in 4gb dimm configurations but didn't think it should run at 667/1333 as the manual states.

The way the dell guy says:

RE: Optiplex 780 - memory compatibility
Again, we only validate ours. We cannot speak to retail memory.

It's everyone else's fault says it all... lolly! There was some sort of problem getting it to run at ddr3 1333, the max the cpu supports, possibly.

qvl is qualified vendors list for ram for your dell. for example a qvl is the ram brand that the comp is "tested" with. for example my msi comp is not compatible with hynix dimms although the same speed and specs.

i see the problem is with outdated qvl's for your old dell. i suspect there is some math going on here thats different.

i hope we can put you on the right track and throw out some talking points my friend.

 

[DavidM012]

not me, the other guy

There is no qvl

The links are dead. Getting 4x4 16gb at ddr 3 10600 1333 did not happen according to previous discussions found so far they run it at 533mhz 8500 speed in spite of paying for keep trying ddr3 12800/1600mhz when the cpu only supports ddr310600/1333 tops anyway.

So no-one knows if or what ddr3 10600 dimms might work on it. at 10600/1333 speed.

 

[gskill support]

I know.

https://www.newegg.com/Product/Product.aspx?Item=N82E16820231424&Description=gskill 424&cm_re=gskill_424--20-231-424--Product

Two of these kits can maximize the system.