No keyboard, mouse power and no monitor signal + DRAM light

Hi, my friend is having trouble with his computer. So his computer monitor isn't getting any signal from the computer. He's tried multiple computers and monitors, so it's definitely the computer.

His mouse and keyboard barely light up either, this is where I started suspecting PSU problems. So I gave him an old 300w PSU so he could power his essential parts, but still nothing.

He's replaced his motherboard with a newer one (got the same model) but that didn't fix it either. CMOS has ben reset, but again, nothing.

Also, his DRAM LED is constantly on. He tried MemOK, but that didn't solve it either, the light is still on. He's got 2x 4gb sticks and they have each been tested one and one on his motherboard. I've also just told him to let the RAM lock themselves in as he pushes them into their slots, so I don't think they're incorectly seated.

We've tested the VGA as well by taking it out of the system and connecting the CPU to the monitor instead. Once again, no improvements.

So we've tried pretty much everything except for the CPU, and we can't be sure if the RAM is working correctly. Suggestions?


Motherboard: ASUS P8B75-M LE
CPU: i5 3450
RAM: Kingston 1333MHz 2x 4gb
PSU: Pretty high quality XFX (irrelevant)

So.. we would really love some suggestions from you : )
3 answers Last reply
More about keyboard mouse power monitor signal dram light
  1. Hi

    Assuming you watched your friend do the tests / swap components and both 24pin main power cable and ATX 12V cable (4 or 8pin) were connected along with power switch connector on second motherboard

    It seems highly probable that it is the CPU or RAM as you have tried a new motherboard
    (or was it a second hand motherboard of un-known working state ?)

    Do you have another PC which takes the same RAM type (presumably DDR3) ?
    to test the RAM using memtest86 or memtest86 + bootable disks (optical or usb)

    Now you need a spare i3 or i5 or compatible Pentium (for socket LGA1155) to test in either motherboard
    personally I would test in second motherboard in case both motherboard and cpu died at same time


    Mike Barnes

    was the cpu being over clocked before before it all went wrong
  2. Hey Mikes, thanks for your response!

    I have a Z77 motherboard with a 2700K and some DDR3 1600 sticks that should be compatible, so I'll check his RAM sticks and maybe the CPU tomorrow.
  3. My friend’s PC ACER Aspire M1640 (running Win7) has been running very slow these last few months, then refused to boot one day. I tried to boot it but it freeze at the win7 logo, with a horizontal coloured line at top of screen. Turned it off via power switch (by holding it down), then took the stick of RAM (1GB) out to re-seat it (earth myself with earth strap, also on PC casing before touching RAM). Re-seated RAM, also re-seated CPU then tried to reboot again (several times); now screen black + no signal to screen + no HD light but HD spinning + no mouse light + no keyboard light/s. PSU seems ok as fan spinning and power is going to motherboard, HD (HD worked in other PC), DVD drive/works, CPU cooling fan spinning. What could be the problem? I’m stuck! Can somebody please help!
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