4 Replies Latest reply on Sep 7, 2015 12:54 PM by backFireX64

    R7 370 2GB crossfire installed; comp no longer POST

    grov3rgil

      Friday I installed new RAM and new GPUs on my motherboard. I contacted the mobo manufacturer about the RAM and GPUs to ensure compatibility before I made the purchase. I ensured the RAM was supported by my processor. I built this system in 2011 and have done nothing to it since then. One rule I failed at was installing one piece at a time. I don't know if this is an actual rule, or just something I did in the past.

       

      At any rate, I plugged my PSU back in and turned on the computer. At first my screen froze on the ROG banner during POST. The LED on my mobo showed an error at CPU (the last of five LEDs). I put the original hardware back in, and got the same result. Now, the LED stops on the first check CPU_PLL. I see that this  is some kind of voltage protection for the CPU. Great, but why now? I also have an amber LED near my HDD SATA connection. It doesn't matter what hardware I have in the case. Old, new, combination, one GPU, two GPUs, two xfire GPUs. It doesn't matter. I tried using the 6+2 pin connections from separate PCIe power sources, or the one that has two from the same line. No change. One thing I have noticed is when the older GPUis installed, the PSU fan runs much, much, much faster than it does with the new VGA installed. The case fans run slow no matter what. The CPU cooler fan seems to be running as it always had.

       

      A buddy of mine who helped me build this thing in 2011 told me I might have a PSU problem. He said my PSU is SLI-ready, but I am trying to run Crossfire. I don't understand that from a power perspective, but what ever. Several forum posts I have read suggest there is no difference between SLI support and Crossfire support, as far as PSUs are concerned. I do not think my system is encroaching anywhere close to 750 watts which leaves me bewildered. I wish I had another PSU to test with. I feared I had fried my processor, but I do not think this is the issue.

       

      I cannot get to the BIOS. I cannot get anything on my monitor.

       

      Does it matter that my mobo has PCIe 2.0 but the GPUs want 3.0?

       

      Old Setup:

      Intel i5 661 3.3 GHz (never OC'ed) (LGA1156 socket)

      ASUS Maximus III ROG (P55 chipset)

      CoolIt ECO ALC contained liquid CPU cooling system

      Corsair DDR3 1600MHz 8GB (4x2) 1.65v

      ASUS ATI Radeon HD 5770 1GB (running solo)

      Antec HCG 750w PSU

      Western Digital Green Caviar 1TB HDD

       

      New Setup:

      Intel i5 661 3.3 GHz (never OC'ed) (LGA1156 socket)

      ASUS Maximus III ROG (P55 chipset)

      CoolIt ECO ALC contained liquid CPU cooling system

      G-Skill Ripjaws DDR3 1333MHz 16GB (4x4) 1.50v

      ASUS ATI Radeon R7 370 (crossfire)

      ASUS ATI Radeon R7 370 (crossfire)

      Antec HCG 750w PSU

      Western Digital Green Caviar 1TB HDD

        • Re: R7 370 2GB crossfire installed; comp no longer POST
          backFireX64

          Either a PSU issue, a connectivity issue (cables or improperly seated hardware), or a motherboard issue, is my guess. The PSU is of good quality and quite adequate to run the crossfirex system, but failure is always a possible scenario.

           

          Read this thread carefully and check your system accordingly and thoroughly (and safely):

          Overclockers Forums

          1 of 1 people found this helpful
            • Re: R7 370 2GB crossfire installed; comp no longer POST
              grov3rgil

              Thank you for your reply backFireX64. I did see that thread upon first researching my issue. I removed everything from the case Saturday to bench test it with no positive results. I performed the suggestions noted within that thread over and over again, with the exception of continually removing, cleaning, reapplying TIM and mounting the CPU. I did that twice. I do not recall having a back plate for my CoolIt unit.

               

              I did look at the reverse of my mobo for cracks and could not notice anything odd; however, I fear this may indeed be the issue. The RAM sticks were a pain to push in and I may have applied too much caveman pressure. I thought I may have grounded something out the way the PSU fan cranked up its RPMs. I did that with improper spacing between the case and mobo when I first built this thing.

               

              I think my only recourse is to find a 1000w PSU to test with (or for replacement in case mine is faulty). Short of that, I am about to scrap all the old stuff for a new mobo and CPU. Before I do that, I am going to bench test it one more time and double check the reverse side of the mobo, including what my cooler connects to.

            • Re: R7 370 2GB crossfire installed; comp no longer POST
              grov3rgil

              I did make a mistake in my description. When referencing LEDs I said CPU_PLL. That is incorrect. There are four LEDs [CPU][DRAM][VGA][BOOT_DEVICE]. This set of LEDs are next to the 20+4 pin socket.

               

              The first couple of starts the BOOT_DEVICE LED lit red. The others were off. Since then, CPU is lit along with HD_LED lit amber. I attached a couple pics.

               

              Lastly, when I took everything out of the tower again for a bench test, I inspected the reverse side of the motherboard one more time. I noticed an exposed copper piece behind the RAM slots. It also appears to be split. And I think I discovered my issue. Don't let He-Man build computers.

               

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