1 2 Previous Next 19 Replies Latest reply on Aug 11, 2011 1:03 PM by rahimbhamani

    Dp55wg error 21


      just finished putting together a new computer. specs are as follows.

      intel dp55wg lga1156 motherboard

      intel core i5 processor

      corsair xms3 4gb pc10666 ddr3 dual channel 1333mhz

      wd cavier 500gb serial ata hd 720/16mb/sata-3g

      ultra lsp750 750watt power supply

      bfg geforce 8800 gt oc 512mb gcie w/dual link dvi (temporary.works)


      first start up, recieved an error code from the motherboards digital display. its listed in the maual as "mec memory detection" as a port 80h post code 21"mrc entry point" error and the computer does 3 beeps in a continous cycle. What i am trying to determine is whether or not the fault is the ram itself or something on the motherboard. returns on parts will take several weeks so i want to be certain as which one i send before i do. system fails before the monitor kicks in so unable to get anything further from it. have not yet tampered with bios settings or attempted an update because of this so everything should be set to factory specs still. please assume that all hardware has been properly installed. this is not the first computer i have built and i have gone over this one meticulously to make sure of that.


        • 1. Re: Dp55wg error 21

          buy kingston ram.

          crazy how many of you go for corsair...makes me wonder

          • 2. Re: Dp55wg error 21

            I had the same problem yesterday (12/11/2009) with virtually the same configuration, and I'm using Kingston's KVR1333D3N9/2G X 2 (for a total of 4 Gigabytes of RAM) so I don´t think is a  "brand problem"; I have built at least 500 PCs by myself and this is the first time it won't start normally... and everything was done by the book.


            I'm starting to thing this is a Motherboard issue...

            • 3. Re: Dp55wg error 21

              Well... I was able to make it work: I populated the third and fourth memory slots (the pair farther away from the processor) and got to pass the memory error. I know it sounds wrong, since the instructions clearly state that "Channel A, Dimm 0 must be populated" but trust me, it worked.


              I already installed Windows 7 and most of the software I use and had no troubles so far; I dared to update the BIOS and try to populate the memory slots as suggested, but the error persisted, so I had to move them back to their original position.


              One interesting thing though: All the SATA ports changed places; this leads me to think that something is wrong about the memory slots two, but hasn't been addressed yet. We'll have to wait and see I guess.


              Hope this will help!

              • 4. Re: Dp55wg error 21

                I just recently bought the same Intel DP55WG board with an intel i7-860 and I just had the same thing happen to me with Brand new G-Skill DDR3-1333 4x2GB ram.  The only way I could make it work was to use Channel B Dimm 0 and 1 to make it 4GB and leaving out the other 2 sticks.  Anyone gotten around for a fix for this or is it a bad board?  I even tried disconnecting all drives thinking it was related to not enough juice and still get error 21.  I upgraded the bios and now instead of giving error 21 it just turns right off if the Channel A Dimm 0 or 1 is used.

                • 5. Re: Dp55wg error 21

                  It turns out that I had a bad ram slot. the board had to be exchanged for a new one. The 2nd one I got worked with no problems

                  • 6. Re: Dp55wg error 21

                    Dang, I was hoping there would be some type of bios update.  Oh well, time to exchange.

                    • 7. Re: Dp55wg error 21

                      Getting the board replaced did the trick.

                      • 8. Re: Dp55wg error 21

                        got exactly the same problem but could not get the system to boot at all. tried all the slots with 1 or 2 modules in different configs but it just wouldn't pass the post. I used i7 860 processor, 2x2048 kingston modules, sparkle 250gts graphics, 1 x seagate 300Gb disk, 1 x western digital 160Gb disk and TV tuner card, PSU is Powerman 550w.

                        • 9. Re: Dp55wg error 21

                          I also have the exact same problem with my dp55wg motherboard.

                          The board won't boot when memory is installed in channel A. (3 long beeps and error code 21 displayed)

                          It works fine with both memory modules in channel B.

                          I guess I'll have to ask for a replacement then...

                          • 10. Re: Dp55wg error 21

                            Hi Folks,


                            I had the same issue. Intel DP55WG, newest BIOS, certified Kingston memory with 4 x 4GB brought up post code 21 and the machine booted in a loop. Kingston support said memory or mainboard seems to be defect.


                            However Post code 21 doesn't have to be defective mainboard or defective RAM. I did not overclock the mainboard but just resetting the BIOS to optimal defaults worked fine for me. I could run successfully a memory test after with having any more errors.


                            16GB: Kingston Part# KVR1333D3N9K2/8G x 2

                            8GB:   OCZ Part# OCZ3P1600LV4GK x 2


                            Hope this helps

                            Greetings from Germany



                            • 11. Re: Dp55wg error 21

                              Guys, I'm really battling too.


                              DP55WG with i5-750

                              2 x 4GB Kingston KVR1333D3D4R9S/4GI

                              Gigbyte HD5770

                              3 x HD of various sizes

                              1 HP SATA DVD 1260i


                              Never managed to get to the stage of loading my 64bit Win7 as I can never get past the POST 21 and triple beep.  Tried one x 4GB RAM in all of the slots but no joy (tried the other one too in each slot of course)


                              Two things that I'm wondering about.  First, my RAM is 10600 parity - but surely the board can cope with that?  It's still 1333 after all.


                              I know that the gigabyte board GA-P55M-UD2 (which uses the same chipset I understand) has very similar problems.  One of their suggestions involved a change in power supply.  Anyone know about that as a potential issue?


                              Any help would be really appreciated.  I'm an older returning student and this problem has turned into a time vacuum!  Additionally, my online supplier will not take any of the parts back - including the RAM, so $$ a bit of an issue.  A few years ago I used to build these things for a living so I really ought to be able to make this work.


                              Thanks in desperation!



                              • 12. Re: Dp55wg error 21

                                Hi guyz


                                i also got the same error.


                                well my PC specs are

                                Processor: intel Core i7 860 2.88 Ghz

                                Memory: Corsair 6 GB (3 X 2GB)

                                Graphics Card: xfx ati radeon 5750

                                PSU : Cooler Master 600 watt


                                Well when i inserted only 2 stick (4 GB) its working fine, but when i inserted one more stick its start beeping and display 21 post code error.I updated the BIOS and also changed the slot, but still have the same issue.


                                do you have any solution regarding the said issue.

                                • 13. Re: Dp55wg error 21

                                  So, I had this issue also.... turns out I didn't read the manual closely enough.  It clearly shows on page 17 that Channel A, DIMM 0 is the blue slot that is closer to the processor.  It also states that Channel A DIMM 0 must be populated in order to boot.  If using 2 sticks of RAM, you have to populate both DIMM 0 slots (i.e. one in channel A and the other in channel B).  One of the techs pointed this out to me during a live chat.  It's confusing because previous boards had the blue slots closer to the processor, whereas this board has the black slot (DIMM 1) next to the processor.  Anyway, once I fixed that it booted!


                                  I should note that it's Intel tech support that keeps me buying Intel Motherboards.  A 10-minute chat and problem solved!

                                  • 14. Re: Dp55wg error 21

                                    Hey bennyboy,


                                    Thank you for your suggestion.  I have just bought 2x2GB Kingston KVR1333D3N9/2G (which are specifically on the tested list).  Took out my 2x4GB and replaced them with the new 2x2GB in the DIMM 0 slots.  Computer turned on for the first time, painless load of Win 7 64-bit (typing this on the resuscitated machine).


                                    I updated the BIOS and then tried putting in my 2x4GB (Kingston KVR1333D3D4R9S/4GI) into the DIMM 1 slots (total now 12GB in 2x2GB and 2x4GB).


                                    Error 21.  Tried just the 2x4GB in DIMM 0, tried swapping every way I could think of.  Error 21 every time until I went back to just 2x2GB.


                                    I have read that some people have had luck with upping the memory voltage, so I cranked it all the way up to 1.6V (in 0.02V increments).  Error 21 every time.  Put the memory voltage back to auto.


                                    I’m really not that sure the board can support anything more than 2GB DIMMs.  I can’t believe that I have an incompatibility between the memories, they are both Kingston PC3-10600 REG CL9 240 pin.  The only difference is that one is 2GB / slot, the other 4GB.


                                    Anyway, I’ll fire this off to tech support, see if they can give me any more ideas.


                                    Thanks anyway,



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