Back screen after new RAM (sometimes)

Hello,

I'm having weird problems recently after installing new RAM in my computer. (default it has 4 GB (2x2), I upgraded it to 8 (4x2))
I have a Packard Bell ONETWO L5710.

I'm having the following problem, it happened twice a row now:

1. I start the computer, nothing happens but a black screen.
2. I turn off the computer, remove all the ram sticks except for one. The computer works fine now.
3. I turn it off again, try with 2 ram sticks (the same pair ofcourse). It still works.
4. I turn it off once again, but put all ram sticks in now. The computer works fine now.

Now comes the weird part; this happened to me this morning. I went to a friend for a few hours, so I turned off the computer. Now I come back and this happens again.

I have no clue why this is happening. I try to boot the computer with all ram in, and it doesn't work, but it does when I pull them out and put them in again?

One important thing: when I came back from my friend and when I tried to boot the computer I got a black screen, but the fan was working really hard.

I hope you guys can help me. My lack of English makes it hard to explain something. Thanks for reading and I hope someone can help me.

There could be a few things going on here:

1. You could have a bad (defective) stick of RAM.
2. You could have an incompatible mix of RAM sticks.
3. You could have a bad, or dirty RAM socket.
4. Your power supply may not be delivering sufficient power to run all 4 RAM sticks at once.

The first thing you want to do is check and compare the specs on the two pairs of RAM. Track down the information and pay particular attention to the voltage, buffering, and ECC specs. These must be the same for all 4 sticks.

The second thing you want to do is download and run Memtest86+ on your system.
I would remove all the RAM and then install one of the new sticks in Slot 1 and test it for 3 to 5 passes. Then switch it out for the other new stick and test it again. There should be no errors.

Then give us some information on your power supply: total wattage, total amps available on the 12v rail, and how old it is.

Also check for the obvious: dust or crud in the RAM slot. A single strand of hair can cause errors.

This is the Crucial Memory site that will tell you exactly the ram which is compatible. This is the only ram they list as compatible.