Mysterious N?

[1vs1comp]

I just built my first machine.

1) POWERCOLOR AX4870 1GBD5 Radeon HD 4870 1GB 256 bit GDDR5 PCI Express
2) AMD Phenom II X2 550 Black Edition Callisto 3.1GHz Socket AM3 80W Dual-Core Processor Model
3) GIGABYTE GA-MA785GM-US2H AM3/AM2+/AM2 AMD 785G HDMI Micro ATX AMD Motherboard
4) Western Digital Caviar Blue WD1600AAJS 160GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive
5)BFGTech 550watt power supply.
6) 2 gigs of ram

I'm having this random start up issue. Most of the time I go straight to Windows with no issues. The computer will do the normal startup and go through component checklist, etc. Sometimes it will freeze up after that screen. It will be a totally black screen, with the cursor blinking at the top left, and a capital N near the center of the screen. What is that? I have to reboot to get past it.

A friend of mine said it had something to do with the mainboard. Is it so? If not then what is it? I'm kind of peeved that my first build has some issues already.

 

[SystemPat]

SystemPat,
(SystemPat, have you tried the Adv BIOS features? Press Ctrl-F1 after entering the BIOS. Nothing too exciting though.)

I didn't think the 785 board has the 'hidden features' in the BIOS. All the stuff that would be there for changing the clocks and volts is on the M.I.T. page. As I understand it, some of this stuff unlocks when using a BE chip ( black edition ).

I can second the fact that the 550 BE runs just fine with the shipped BIOS on the board. BIOS flash update not required.

I won't get dragged any further into the memory speed and voltage issue. There is mass confusion on this all over the place, partly because the standard, the JEDEC standard, stops at DDR2-800. So the SPD rating for the 1066 and the 1200 memory is still an 800 setting (from what I've seen - I don't spend all day on this) and few if any motherboards can set the higher speeds on AUTO. So as system builders we have to go to the BIOS, change to MAN settings and up the voltage and the multiplier thing to match what's on that particular memory model. And the voltages are different from one to another. It is definitely NOT plug-and-play. If I did it again I would probably buy the 1 or 2 brands that will do 1066 on 1.8 or 1.9v. But the Patriot Viper memory has worked just fine for me.

One warning on the memory speed issue. The BIOS posts the speed based on the setting of the multiplier apparently. I dropped the multiplier back to 4.0 when I boosted the FSB speed. So mine is really running at 4 X 250 = 1000. But the BIOS shows 800 on the POST screen.

 

[SystemPat]

Wow. I figured it out. This is going to be really stupid sounding. I noticed when I loaded the defaults for the BIOS it gave me a YES or NO question about the SATA connection. I hit N for NO a few times. It gave me the mysterious screen and then it hit me. I kept holding down keys during post and lo and behold I got the error. UGH. I'm sorry for wasting everyone's time for such a stupid user error.

I had to laugh at this. Because it happens. Yes, you don't want to hold down a key during the boot or hit a key too often. It does not like the distraction and will stop playing and go home!!!

 

[Mongox]

SystemPat - the Ctrl-F1 Adv BIOS features does do something on our MB. Adds an additional item to the main menu and a couple of items inside the menus. Haven't found anything useful there tho. There is something called "Swiggly RAM" or something like that! I'll have to take notes on it and investigate.

Upgrading to BIOS F4 did fix an odd thing I had happening right after POST. If I had the CPU temp sensor warning turned on (like at 70C) in the BIOS, I would hear this sound for anywhere from a second to more, either one buzzzzz or more, right as Windows started. Quite annoying but I liked having this warning in place. F4 fixes this problem. (There was never any reason to think the CPU was really reaching this temp, but as Windows starts it seems to have a few seconds where it's taking control of these features and drops the ball.)

No matter what changes you make to FSB the POST will show predefined numbers for the RAM speed. So if its manually set to 4.00 then it assumes the RAM speed is 800; if set to 5.33, it assumes 1066. So I'm pretty sure if the RAM muliplier is set to 5.33 and FSB to 150, it would still show 1066.

I did try 3 different RAM modules on my board. The 1st would never show 1066 on Auto or Manual due to 2.2V requirements. The 2nd showed 1066 on Auto without a problem. My current RAM does require the change to Manual 5.33 to show as 1066. But I'm using it as 800! So sometimes it'll read the EPP - no idea why or what the difference is.

 

[SystemPat]

If I had the CPU temp sensor warning turned on (like at 70C) in the BIOS, I would hear this sound for anywhere from a second to more, either one buzzzzz or more, right as Windows started. Quite annoying but I liked having this warning in place. F4 fixes this problem.

BIOS - I'll try the ctl-F1 when I get a chance. But, Does not sound like anything vital there. On my 2nd system, running a GB AMD690 chipset with an Athlon X2, all the clock and speed settings were out there.
That extra beep or buzz. I've had it off and on too. Not sure if it's the temp warning or the CPU fan warning. Kind of thought it was the fan warning. It's only there for like a half of a second or so, so it goes by quickly.
I bought the Patriot Viper memory partly because of a mail-in rebate. Which I have not received yet. It has performed with no complaints once I stepped up the volts and the settings, including all the little cycle settings (5-5-5-15 something like that). But the 2.1v is at the max adjustment for the mobo. I'm not trying to OC the memory. And I've boosted the mobo settings about as far as they will go at 3.6gz. I might even back it down a bit as I'm more interested in the long run.
What are you using if anything to monitor temps from Windows? Don't need to watch it all the time as it seems to run cool enough but like to check occasionally.

 

[Mongox]

You can test the buzzzz sound by disabling the Temp Warning in the Health options and rebooting. No Buzzz. Then turn it back on and it's back. As I said, BIOS F4 fixed this annoying problem for me. Also, if you change the Temp setting from 60C to 70C etc, it'll change the number/length of the buzzz!

I'm using CPUIC's Hardware Monitor. I actually installed the registered Pro version so I could re-name the Fans and Temp sensors. Also let's you put any readings you want on the System tray if you want while testing. But the reg version works well.

I'm still not sure which temps the 3 sensors show! I know the middle one is the CPU temp - easy to tell that. I've decided the 3rd one is the "Case" temp - and labeled the 1st one the "Board" temp, but really don't know!

In addition, it may show the temp sensors for your hard drives. It shows the Core temps for the 550 when running on 2 cores, but nothing on 4 cores as there's no such Phenom as a B50 (950) in its database.

AMD's Power Monitor is handy just to visually see what the 4 cores are doing. And AMD OverDrive has all sorts of very interesting info even if you don't use it to modify your BIOS settings.

This link has all the programs - and a lot more!
http://forums.tweaktown.com/f69/latest-overclocking-programs-system-info-benchmarking-stability-tools-30530/
Some you might want to chk the homepage to make sure of latest version.

 

[mark1900]

I had the same problem: black screen, green block and capital N letter (Gigabyte ultradurable motherboard UD3P something). Keyboard was the cause with my machine too but it was caused by almost empty batteries. I have wireless microsoft keyboard. I replaced the batteries and the problem was fixed.

 

[HellboP]

Pertinent Information:
-Gigabyte GA-MA790XT-UD4P ATX Motherboard (AM3+)
-Standard PS/2 Microsoft Keyboard
-Mionix Naos 8200 USB Mouse

This problem appears to be with older Gigabyte motherboards, and as such, I'm not sure how useful this information will be to the community. I thought I'd post my most recent adventure with the mysterious N just in case it helps someone like me running an older build.

This issue just cropped up for me when I reinstalled Windows 10, and persisted no matter what OS I used (I changed them to troubleshoot, using Windows 7 and the latest version of Ubuntu). For me, this was most definitely a hardware issue, and later became very obviously the fault of the Gigabyte motherboard.

For whatever reason the motherboard seemed to have decided that it hated native USB mouse support (an option available via the BIOS). I have installed no new hardware, so I'm unsure of what prompted this change. Every time I booted it would POST and then display the Mysterious N, never was I able to enter BIOS settings. As it turns out, at the same time, it also decided to stop accepting input from my PS/2 keyboard.

In order to diagnose and fix the problem, I unplugged both my USB mouse and PS/2 keyboard, plugged in a borrowed USB keyboard, fully powered down and then rebooted. Only then was I able to successfully enter my BIOS settings. Once there I set everything to the fail-safe defaults and slowly changed my settings back until I identified the culprit as the enabled USB mouse support option. Disabling the option has allowed me to successfully boot the computer and I now have full functionality in my PS/2 keyboard.

Unfortunately, in order to keep using the mouse, I have to boot once and manually initiate the USB mouse driver (this may or may not be necessary for you, but I suspect the two restarts and the clicking will be) , and then restart. During the restart I have to periodically click the mouse button (in my mind, to remind the computer that it's there) and on this second boot I then have full peripheral functionality.

If anyone has a better fix I'd love to hear it - and again, I hope this information is helpful to someone 6+ years after the start of this thread.