dell optiplex only work with one memory at the time

Hello Bobdolo,

In order to assist you, please help me understand the following details:

• How may memory sticks are installed in your computer?
• What happens when you try to boot the computer with all the memory sticks installed?
• Please elaborate the issue.

There are few steps I would suggest, which would help us in isolating the cause of failure, please try the following steps:

• Remove all the memory modules from the computer and check if any beeps are heard.
• If you hear the beeps, it means that the motherboard is working fine.
• Then try only one memory stick at one time, in each slot. Example: Take one memory stick, insert it into the first slot, and check if the computer boots to windows. Then try the same memory stick in second slot and follow the same pattern until you test all the memory in all slots.
• This would tell us if the issue is with mother board or memory.

Please try the steps and write back with your findings. 

i try the steps and the board is fine and two memory slot are working.

The pc have two memory slot but only one work at a time.

if i place memory in the two slot the pc will not boot

What next

i try the steps and the board is fine and two memory slot are working.

The pc have two memory slot but only one work at a time.

if i place memory in the two slot the pc will not boot

What next

Hello Bobdolo,

I would request you to try updating the BIOS to the latest version.

**NOTE: Few things to ensure before updating the Bios is, the Ac Adapter should be plugged in and the battery should have minimum of 15% charge. No other external peripherals should be connected to the computer. Please ensure that the Bios update should not be interrupted else it would damage the motherboard.