"No Signal" with Sapphire HD Radeon 7850

[wayne62682]

I just bought a new Sapphire HD 7850 graphics card to replace an aging NVIDIA GEFORCE 9500GT. It installed fine, I plugged it into the power supply, but when I power it up (HDMI) both fans are going but I get no signal at all to my monitor. The only thing I didn't plug in is the Crossfire cable (couldn't find where it went, derp)

My motherboard is a Gigabyte; from the information I found the model number is GA-MA770T-UD3P if that helps. The old video card works fine. I do have the Radeon software but I was under the impression that would get installed after the computer booted up, and that I didn't need to uninstall the NVIDIA graphics beforehand. The computer doesn't seem to have onboard graphics (the only monitor plug is in the graphics card). I don't get a bios check or anything but when I started it up with the old graphics card I did get the "windows didn't start correctly" screen which indicates that it is starting up fine.

Any help would be appreciated, as I really do not know why the video card isn't getting the signal sent to the monitor.

I should mention I also upgraded my CPU at the same time to an AMD Phenom II X4 965. Now that I tried my old graphics card, it seems to stopped working as well. I got it to load up once, but Windows froze up quickly and now I get "No Signal" even with the old graphics card.

 

[clutchc]

If you changed the CPU and GPU together without uninstalling the Gfx driver, I can see why Win7 might get a little confused. But you still should get a display in the boot up screen. In fact, the BIOS should ask you to enter the setup part of the BIOS to reset the parameters when seeing a different CPU.

Did you:
Check to see if the monitor got switch accidentally to a different input than you are using? i.e. DVI, VGA, HDMI.
Remember to plug in the Pcie pwr cable to the card?
Remember to plug in the cable between monitor and card?

You might try resetting the CMOS to its default values. Remove the CMOS battery and jumper the Clr Cmos pins for a few seconds. Replace the jumper and battery. (pg. 31 in your manual)

 

[wayne62682]

I will try that but what would cause the problem to persist after I swapped back to my old gfx card? The common factor seems to be the new CPU since I get no signal with the old gfx card that worked until I tried to replace it.

 

[clutchc]

I will try that but what would cause the problem to persist after I swapped back to my old gfx card? The common denominator seems to be the new CPU since I get no signal with the old gfx card that worked until I tried to replace it.

I'm kinda grasping at straws here, since it is always hard to troubleshoot from afar. Was the CPU new or used?

Is your BIOS updated to accept the 965? What was the old CPU?

 

[wayne62682]

CPU was brand new. The old one was an AMD phenom II X4 810 so I did not touch the BIOS.

It started up once with the new CPU + old gfx card but after that one time it won't display.

 

[clutchc]

I would say the BIOS is the right version then, since both CPUs require the same one (ver. F5)
I would continue to troubleshoot with the old card in place for now. Maybe even replace the old CPU, if resetting the BIOS fails to fix things. What size/make/model is your PSU? How are you connecting your old 9500 GT to HDMI, with an adapter?

 

[wayne62682]

The 9500 GT has an HDMI port, no need to use an adapter.

I just tried the monitor with another PC and it works fine so it's something with the new CPU (maybe BIOS, have to see how to reset that and give that a try). My PSU is a Logisys PS480D2 which is a 480W.

 

[clutchc]

The 9500 GT has an HDMI port, no need to use an adapter.

I just tried the monitor with another PC and it works fine so it's something with the new CPU (maybe BIOS, have to see how to reset that and give that a try). My PSU is a Logisys PS480D2 which is a 480W.

The PSU may be your problem. That model is a very low quality PSU and only has a 16A +12V rail. Your HD 7850 alone requires almost 11A (maxed out) fully loaded. You may have blown the rail in it with the HD 7850. Try switching off the PSU and unplugging it for about a 1/2 hour. See if it comes back to life with the old gfx card in place.

 

[wayne62682]

The PSU may be your problem. That model is a very low quality PSU and only has a 16A +12V rail. Your HD 7850 alone requires almost 11A (maxed out) fully loaded. You may have blown the rail in it with the HD 7850. Try switching off the PSU and unplugging it for about a 1/2 hour. See if it comes back to life with the old gfx card in place.

Well, I switched off the PSU for a while and tried it again, no change. So it looks like the PSU is the culprit and I'll need to get a newer, more powerful one.

 

[clutchc]

Well, I switched off the PSU for a while and tried it again, no change. So it looks like the PSU is the culprit and I'll need to get a newer, more powerful one.

You may have to physically unplug the PSU for it to reset (if it is capable of resetting). But, yes, that PSU is too low powered for that card and the rest of the system even if it isn't the problem.

 

[wayne62682]

Yep, I'll just add that to my list to buy. You've been a great help, thanks!

 

[wayne62682]

Best answer selected by wayne62682.