RAM fits in Comp but Monitor doesn't turn on. HELP

[NeciFiX]

I recently purchased a 512 MB stick of RAM for my PC. I made SURE it worked with a PC shopmen, and I made sure my motherboard was compatible. I have 0 viruses etc and 20 gb of free memory. My comp is a Compaq Presario, a bit old so the Motherboard can only sustain 512 MB of RAM. I put the stick in, success! It fits. We then turn the PC on, it works, but the monitor stays OFF. We checked 5 times to see what was the problem with no success, so my brother and I then put the 126 MB of RAM back in (it was hard to get a hold of this, my comp is living in the 90's) and the 126 MB of RAM worked, and then we moved the 512 over a slot, to no avail it STILL wouldn't work. Can you tell me what is wrong? I will post my system specs and the RAM specs.

RAM: 512MB PC133 CL3 (SDR below)

System Specs:

OS: Windows ME (soon to be XP)
Type: Compaq PC
Manufacturer: Compaq
Processor: Intel Pentium III, ~930 MHz
Current RAM: 126 MB
DirectX: 9.0b
Series of Compaq: 5003 US (of the 5000 Series)

Can ANYONE tell me why my monitor is not behaving and not turning on? This is extremely unfortunate. I am used to being let down/not getting what I want on a constant basis but this is just plain ANNOYING! PLEASE HELP!

Issue: 512 MB RAM works in PC but monitor does not turn on. Please read above.

Thanks.

~Sam

[GX1_Man]

I believe the 5000 series could only hold 256 RAM per slot for 768 total. So, while it can use 512 RAM, it CANNOT use a single 512 meg. chip. I hope you can get your money back. I think they also used CL2 and some Compaqs are VERY particular about the RAM.

Have a read:

http://www.crucial.com/store/listparts.aspx?model=Presario+5000+Series+Model+5000US

Unfortunately, because "it fits" does not mean anything other than it fits.

[NeciFiX]

Ah Jesus, I'm sure I can get my memory back... but ... the inside of the PC, unless I didn't see, had only TWO slots, there was no third slot. Hm... does this STILL mean I can only fit 254+254. *censored*, this is really annoying.

And I think this is my PC, I checked, only 2 slots. This is my PC.

http://www.crucial.com/store/listparts.aspx?model=Presario+5000+Series+Model+5003US%2E

But, I still think your right.

[GX1_Man]

256 is the biggest in any one slot in the 5000 series. Sorry.  

[NeciFiX]

Well, now I know. Thanks, I'll just trade the 512 MB for 2x 256's. He'll let me do it, he's my bud. Haha, thanks though. Now I know.

[GX1_Man]

You're welcomed and let us know how it works with the correct RAM.