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First, I know it won't get through POST. No RAM/CPU make that fairly obvious. There is a 2-digit seven segment debug display on the board. (It's an ASRock Z77 Extreme4.) Can I expect any of the following, if the motherboard is good?

  • The 2-digit 7-seg display to have some diagnostic code, probably something along the lines of "No CPU"
  • Power LEDs on the board itself (if they exist) to light?
  • Whirs or full-action from case fans or PSU fans?

    ...basically, some sign of life.

I'm looking for some way to isolate and test just the board itself.

The PSU looks okay: shorting the green wire to a ground I was able to power fans, and a DVD drive that seemed to be endlessly resetting itself (probably due to there not being anyone on the other side of the SATA cable).

Also good to know: Would powering it up without a CPU/RAM damage the motherboard? I can't see why it would, but you never know...

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Try it and see... :) –  ChrisN Feb 10 '13 at 1:49
Typically with missing ram and/or CPU, you'll get system beeps (old school -> 3 beeps for bad/missing memory) –  kobaltz Feb 10 '13 at 1:56
@kobaltz, yep, with speaker attached or an on-motherboard speaker, the motherboard just complains loudly at you, just not as interestingly as R2D2. –  Fiasco Labs Feb 10 '13 at 2:11
Well, I tried it with just the main motherboard power cable attached (not the CPU power connector) and got nothing. So I went from there and installed the CPU (and connected the power connector) & a single stick of RAM (twice, with two different ones, as I have two RAM modules), and still nothing. Something is horked, but I don't know what. –  Thanatos Feb 10 '13 at 4:31

1 Answer 1

Booting a motherboard without RAM should cause beep codes.

However, from the few motherboards Ive powered that had no processors, no beep codes were generated.

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I've done this with a dual-processor server missing processor 1, and it did give a beep code (this was a server motherboard with a second processor installed, but the manual indicated that it was a generic "no processor installed" code - processor 1 [removed] was apparently mandatory, and processor 2 [installed] couldn't fill its role) –  cpast Feb 10 '13 at 2:56

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