Question New MSI MAG Z790 Tomahawk build has no video output

[Tom Vrankar]

Benchtesting (no case, no GPU) new MAG Z790 Tomahawk Wi-Fi DDR5 build. Don't get expected BIOS/UEFI screen on monitor.

Installed I7-13700K (not F) with dual-fan air cooler wyed to mobo. Installed Ripjaws DDR5 kit in A2 and B2. Installed new, uninitialized, SSDs in M.2_1 and M.2_2. No SATA devices installed.

Keyboard connected to arbitrary USB 2.0 on mobo. Monitor input manually switched to DP and cabled to mobo DP connector so monitor doesn't complain about missing input

PSU connected via one large mobo cable and two CPU cables. FP1 power switch pins tapped and PSU and CPU fans started slowly, keyboard power indicator illuminated, and mobo POSTs through to only green LED: no boot device, I assume because SSDs are uninitialized and no other possible bootable devices installed. During and briefly after POST LED sequence, I mashed F11, DEL, and F2, but no joy: nothing shows shows on monitor (not even the splash screen reminding you which key gets you into BIOS - literally nothing).

What am I missing? Is there a jumper or other means to force video output to mobo DP connector? GPU won't arrive for days. Without monitor I can't update boot devices or M-Flash a BIOS update.

Help!

 

[thestryker]

I'm assuming none the debug LEDs towards the upper right of the board are on.

While I can't think of any logical reason why it wouldn't be working aside from hardware failure have you tried the HDMI port just in case?

 

[Tom Vrankar]

I'm assuming none the debug LEDs towards the upper right of the board are on.

While I can't think of any logical reason why it wouldn't be working aside from hardware failure have you tried the HDMI port just in case?

The debug LEDs (that I called POST LEDs) sequenced through red, yellow, white, and stopped at green. The manual says this is "booting device is not detected or fail". On another forum they say this means that no device that could be configured as bootable has been found: in my case that both SSDs, one on CPU, one in the chipset, from two different manufaxturers, have been installed incorrectly. I'll be going back to check on them.

But to this forum's knowledge, does this green LED always indicate a failure? Seems a funny choice of color. Or is it really that it indicates the end of POST and if you didn't get to BIOS it's because no boot device found, otherwise green means go? Or should all these LEDs be off for success? if I didn't install any drives of any kind at all, would I also not have gotten to BIOS? Also, what is the default boot order; is it okay that I don't have a SATA device installed? And is it okay that of these PCIe drives, neither has been initialized to be bootable yet?

Monitor only has DP and DVI inputs. I had been using the DVI for the last 8 years for my previous build (RIP). I have used the DP only a few times over the last year using a visiting laptop's USB or thunderbolt to DP cable. I picked up the DP-DP cable yesterday at Best Buy, and I guess I could pick up other adapters to try other combos.

If it matters, I'm following as much of the LTT Building a PC how-to video as there is.

 

[thestryker]

If any of the debug LEDs are on that means your system won't boot. It stopped on boot device which makes complete sense because you haven't installed an OS. Now what this means is that your system is working properly you're just not getting video output. This could mean a bad cable, or something with the output port on the motherboard itself. That's why I suggested trying the HDMI port just to see if you got output. If you have a TV or any other display with HDMI you could always try that temporarily just to see what happens.

 

[ruppfel]

Hi, I have the exact same problem with the same motherboard. The system seems to boot normally, if I plug-in my windows install stick, I do not get the green debug LED as it detected a boot device. If I do not have it plugged in, I get the green LED, so that seems to work as expected, but I don't get any display output whatsoever. I tried changing out the RAM, taking out the GPU and connecting both HDMI and DisplayPort directly to the Motherboard, flashing BIOS, taking out CMOS and putting it back in, all with unchanged results. Did you ever discover a solution to this problem or has anybody else an idea, I don't know what to do anymore.