4 GB Ram Upgrade problem - OptiPlex 780 Desktop ..

Have you tried installing the 4GB modules one at a time? If 'no' then try installing all of them one at a time and see if it boots individually. Make sure the other three slots are empty.  FYI, you need to have a 64Bit OS for your system to recognize above 4GB though that's not the issue here, I kinda wanted to remind you regarding the same. 

The crucial memory and the Kingston is almost the same except the speed. According to the light code it should be a improper configuration. Looking forward to your reply. 

- Yes as I did tried installing the Ram one at a time and all of the other slot are empty but end with same result buzzing and windows not booting.

- Regarding the 64-bit system, its already installed, So I can have the full of 16-GB Memory readable.

- Third thing, I did an online test by the crucial & memorystock websites and I am pretty sure that the memory is compatible before I bought them, I checked the timing - voltage required - capacity.

Thanks for the replay.

Any other solution?

Is it too slow? so why the crucial gives me the same featured for the compatible Ram!

Thanks for replay.

Still problem here ..

The crucial Ram is  PC3 12800 (1600Mhz)

8GB Kit (4GBx2)  
DDR3 PC3-12800 • CL=11 • Unbuffered • NON-ECC • DDR3-1600 • 1.5V • 512Meg x 64 •   •  Part #: CT4003699

The Kingston DDR3 PC3-10600 (1333Mhz)

Its not compatible.

  Its not going to be compatible. You can see for yourself its low slow beeeeeep = Bad = not compatible.

Okkkkkk O K .. O . K . I understand that you give the best solution ever in my life I swear to God.

but I am wondering here after I bought the Ram and I lost the Bucks .. Why the hell did dell says in the guide page of the Dell 780 the compatible ram is "16GB1 DDR3, 1066MHz/1333MHz, (4 DIMM)"????

Can you tell me please?

And even Crucial website says the two types:

DDR3 PC3-12800 >>>OR<<<< DDR3 PC3-10600

See the attachement:

http://i198.photobucket.com/albums/aa22/BYQ-/2014-04-25_13-54-51.jpg

And thanks for the help Mr cleaver :)

Same deal here.

Every reference I can find online, in both Dell's documentation and various memory manufacturers and vendors sites, says that PC3-12800, maximum of 4GB sticks, IS compatible with the Optiplex 780.

However, they are all wrong. I've tried three different manufacturer's on three different 780s, all with the most recent BIOS, none work.

Contrary to everything posted, the Dell Optiplex 780 cannot handle higher speed than PC3-10600.

Seriously frustrating.

Originally I had 2 x 2GB 2Rx8 PC3-8500U (Kingston) on my Optiplex 780 running Windows 7 Ultimate.

Two weeks ago I bought 4 x 4GB 240-pin DDR3 PC3-10600 1333MHz from MrMemory.co.uk (see below).

I tried to install the new RAM (still on Bios A01) attempting with the individual 4 GB modules and all four together, but it didn't work and in all cases I was getting diagnostic lights 1 & 3 ON.

After updating to Bios A15 and the other recommended Dell drivers (perhaps the latter were not needed) I managed to get my machine working with 16 GB. What a relief! According to the Bios, the new RAM is working at 1066MHz though.

I didn't change any default configuration in the new Bios A15, and I didn't have to change the original motherboard or the power unit (300W) as other people claim did. Perhaps I am just lucky :-)

Best wishes,

Luis

Ok, after some playing around with switching memory modules in and out, I did manage to get *one* of the memory modules to work.  I suppose it's possible that there is a problem with the other memory module, and I plan to contact the seller to see if I can get a replacement. I'm just afraid it will turn out to be the 780. :-(

My solution copy pasted from another topic about this issue: Hey guys, I just bought 2x 4gb's of ddr3 10600, for my Optiplex780MT  and at first it wasnt working. Doing a bit of a search made me start to get a little pissed off but this board does take DDR3 10600, hell it already had 2x 2gb sticks of DDR3-10600 in it and worked fine. That didnt stop it from not booting when i put in the new RAM. A bit of trouble shooting and I was able to fix this problem, rather simply. First upgrade the bios, to A15, mine was still on A01. Download it from the dell downloads page, then run it as an administrator. When the update is finished, turn off the computer, unplug it, open the case. Hit the power button again to drain power until the LED's go out Install the new RAM. Shut everything up, plug in the computer and power on. Viola, that's what i did, you now need to enter bios because the configuration has changed, be sure to check the HDD AHCI/ATA/RAID to the correct setting, updating the bios set the default to RAID, I put it back to AHCI auto detect once i figured out why windows wasnt starting. That's pretty much it, now running 8 gigs of PC3 10600 1333Mhz that its clocking down to 1066mhz. So you know, it was running with the A01 Bios on 2x2gb of:  hynix 2gb 2rx8 pc3-10600u-9-10-b0 (HMT125U6TFR8C-H9 N0 AA     1031) I dont know for sure, but i assume you could use 4 2 gbs easily and this stuff is pretty cheap on ebay Now it is running with A15 Bios on: 2x4gb Crucial ct2kit51264ba1339 -- This is no longer available on their site and is possibly discontinued but I got it new w/ lifetime warranty on amazon for 84 shipped with tax, and its on newegg too for 90. Anyway hope this is helpful, just waiting now for the hdd, vid card and psu to arrive to hopefully turn this freebie computer into a relatively decent machine.

I just bought this exact RAM for my Optiplex 780, 2x4gb Crucial ct2kit51264ba1339.  I followed these instructions exactly.  And... no joy. :-(  The machine will not boot.  I get some beeps, and lights #3 and #4 come on.

Please help, what am I doing wrong???  This is *so* frustrating!

Has anyone had any luck running 12800 RAM in the 780, even with the latest BIOS A15? What did the OP BYQ end up running in his 780? 10600? I bought 12800 RAM kinda by accident so not sure if it's gonna work or if I'll have to return it.