10600 vs 12800

I have a Dell Optiplex 3010 which is showing nothing on the screen and I don't hear it accessing the hard drive. There are two indicator lights on the front panel showing - a #3 and a #4. Dell's documentation says that indication is for bad RAM.

The machine has two slots, with one being empty.
I pulled the one 4 GB PC3 12800U module and put it in the other slot. Same indications.

I have a couple of 1 GB PC3 10600U modules. I tried each of the two, one at a time, in each of the two slots. Same indications.

I'm pretty sure the two 1 GB modules I have are good.

Could it be that this machine needs the 12800 type of RAM? Or maybe the board itself is bad.

I did note that if there is no RAM installed the machine beeps when powered up. One beep followed by three beeps followed by two beeps which I believe means "DIMMs not being properly identified or used" (per the user guide)

 

You can use the different speed RAM in the Dell it just means it will run at the slower speed.
Sounds as if the DIMM slots have gone bad or the board is faulty.

 

Thanks both for your replies. I hate to deem a board bad.

 

Are you sure that the replacement RAM is good?

 

I'm pretty sure, but haven't tested them in another machine. So they both could be bad. IJAC has some RAM he's going to lend me.

 

IJAC brought over some RAM that he had and was known to be good. We tried it in the machine. Got the same results.

He was sitting behind the machine and noted that there was no heat coming off the CPU fan. We checked the temperature at the fan outlet and sure enough, there was no heat coming from the CPU fan.

We then checked PSU voltages with the machine fired up by pack-probing the connectors. The voltages were good. So it's either the board or the i5 CPU.