Monitor Signal Loss/Reboots

OS - Windows 7 x64
Video Card - XFX Radeon HD 4870 Video Card - 1024MB GDDR5
Mobo - ASUS M4A79T Deluxe AM3 DDR3 AMD 790FX ATX AMD Motherboard
CPU - AMD Phenom II X3 720 2.8GHz
RAM - G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
HD - 2 SATA drives (Highly doubt it would be causing the issue, can provide exact models if needed)

Like the title says... thats the issue I'm having. I had left my PC running... mother came in to check it out my new rig and the monitor signal was lost then the PC shut itself down and started to reboot... it would reboot during startup and occasionally get to Windows 7, only to lose signal and reboot again (couldn't even get that far into BIOS with it restarting).

So.. at first I thought it could perhaps be my Power Supply as I remember that had something to do with random reboots...

So I pop open the case and turn it on to see if anything fishy is going on and... blam... the fan on my brand new Radeon 4870 isn't spinning up at startup with the card. I give it a flick or two and it starts spinning. The PC hasn't crashed since.

I just built this new rig on Friday night and it has worked flawlessly ever since... playing many games just fine on high settings with zero crashing. My mother comes to see how fast it is and it crashed thus.

What tests could I do? Could it be something else wrong? I've shut it on/off a few times and the GPU fan has worked fine since I gave it a little flick...

Any advice? Suggestions? I've read up on this card running hot... I'd rather not be stuck with a dead brick card so I'm trying to get this all squared off before I can no longer return it.

15 answers Last reply Best Answer
More about monitor signal loss reboots
  1. Best answer
    Let me make sure I understand you right: you're saying after you opened the case and gave the GPU fan a flick, it ran fine - right?

    If so, then the case seems clear: without its fan, the graphics card ran hot, shut off, and forced the system into that reboot cycle. All that's going on is that that fan sometimes gets stuck. You could either watch it for a while (run HW Monitor on your system to watch the GPU temp) or return the card right away.
  2. Yeah - thats pretty much what happened. It's failed to start a few more times, and other times it has started right back up again.

    My card idles around 60-63c (though this appears to be a normal temp)

    I'll probably RMA it so I don't have to deal with it later... unless it'd be worth it to drop an aftermarket fan on the GFX card (if its possible)?
  3. I think it's possible but rarely a good idea. That fan is matched with the card, and RMA'ing is going to save you money anyway. I know having to wait for it is hard. Maybe you have an old graphics card lying around somewhere? :D
  4. Heh. Yeah, an old ATI x1850 but it won't work with Windows 7. I'm setting up the RMA now..

    My other issue that I've found is that my g.Skill RAM isn't running at the proper speeds. Upon asking Google... seems like this is just something common and it isn't fully supported by my mobo... it said they were going to release support for it in an update also... trying to decide if I should just RMA the memory too...
  5. All you have to do to get your RAM running at its rated specs is to manually set the RAM speed/timings/voltage in the BIOS.
  6. You sure the card won't work with W7? You won't get Aero, but it should be fine for basic use.
  7. All of the compatibility tests I've run had come up nil and I couldn't seem to locate any drivers. I'll live without for a few days... theres other PC's in the house that I can use in the meantime.

    I went and upped the voltage to 1.6 and the frequency to 1600 on my RAM, however, I cannot find the CL timings to set them to 7-8-7-24. Is this done automatically?
  8. The motherboard owners manual will tell you how to set the RAM timings.
  9. Aye, I had scoured the BIOS and couldn't find it only to realize I had to change a setting from Auto to Manual to even get that submenu to be accessible/viewable.

    My last question now...

    How do I manipulate those settings to achieve the listed/desired speed on my card? Theres a bunch of different settings (This is the part I'm unfamiliar with)

    Edit - Seeing something similar to this page...

  10. The timings that you change are the first four values.
  11. For both sections or only the first?
  12. The first four values in the "1st Information" section. They're currently set to 7-7-7-21.
  13. Well, I went in and changed the first four to the timings advertisted, along with the voltage and clock.

    Save and Exit... screen goes black. On reboot is says "Overclock Failed!"

    I'm going to keep scouring the internet for some answers. I think I remember saying this was a known issue with this Mobo/RAM/CPU setup or something... I'll try to find it again.
  14. Did you have your system OC'd before making the changes?
  15. Nope.

    The further I read seems to indicate that 1600MHz isn't an easily attainable stable speed for my motherboard or CPU or somecrap like that.

    I made another post inquiring how to lower the MHz and tighten the timings as I wouldn't know myself. More specifically what settings etc. is the post - I figure it'll be easier to search for those who are having the same/similar issues.
Ask a new question

Read More

Homebuilt Graphics Cards Systems