I wanted to setup a 2 CPU server, but was not able to even POST with 1 CPU (x5550) and 4gb of ram (unbuffered).

I have only the following hardware connected:

1) VGA monitor (checked cables, it works elsewhere) 2) USB keyboard 3) SSD disk (also used other, new, working Samsung 2 TB disk) 4) CPU with passive heatsink 5) 680W PSU

No original, 6 pin fan was connected (there are 6 slots for them). I used molex type fans, hence motherboard thinks that there are no motherboard fans connected. there are 8 green LEBs in the corner, blinking (no idea how to read them, no info that I could find in the HP materials for that motherboard). The motherboard starts immediately when the PSU is in on position - I noticed a red, single blink of a led next to CPU2 and CPU2_RAM slot (I assume it is to indicate that there is no CPU/RAM in #2 slot).

Would the regular, 6 pin fan connected to motherboard solve the problem (and if so, how many are needed at minimum)?

  • What cooling do you have on the CPU? Mar 26, 2015 at 20:01
  • molex type, wont be detected by the mobo, hence my question with regards to 6pin fan connected directly to mobo. Mar 26, 2015 at 20:49

1 Answer 1


No, this won't work.

I don't know where you obtained this equipment or why its missing fans, but you're not using it as intended. HP servers don't post without the requisite set of fans.

In this case, there are SIX fan slots. You need FIVE in order for the server to operate. Please see the maintenance guide for this server.

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  • ewwhite, I got that, I wanted to put it in the eATX, wanted to know, what is the minimum of fans needed for mobo to start. 5 to start is great info, I couldnt figure it out of the hp manuals (I just guess You interpret the one to be optional from the manual). I have different fan/s connected in my eatx setup (I know, its not standard), wanted to know how many (minimum) I will need to start the mobo (POST). thanks a lot! Apr 7, 2015 at 16:05
  • 5 is not my interpretation. It's what is required for this platform.
    – ewwhite
    Apr 7, 2015 at 16:20
  • Connecting 5 fans didnt solve the problem. Is the red led (first, the one close to DIMM2 and then CPU2) single blink indicator of no CPU2, or it has some other meaning. Fans wouldnt turn at all, only the PSU fan turns for a second and then DIMM2 / CPU2 led blink and thats it, no POST. Apr 14, 2015 at 0:22
  • Would it be possible that memory is not compatible with the system: I am trying to use Crucial 4Gb 2RX8 PC3-10600U-9-11-B1 ? Apr 14, 2015 at 0:29

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