Mysterious N?

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.
31 answers Last reply
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  1. I have the same motherboard and cpu you have, maybe I can help.

    First thing that I notice is that your PSU is the minimum recommended by Giga for that system. I only have a 585 but you have the add-on graphics card and I don't.

    Inconsistent errors are the bane of troubleshooters and tech guys. If you can't duplicate the error on demand, then it's very hard to diagnose. You can "fix" something and not discover until weeks later that it's still doing it.

    The N is what's usually called an artifact - something left behind when an error occurs. The fact that it's an N is likely not important - but might be! I found nothing searching for this error.

    First thing to do is to go into the BIOS and choose Optimal Defaults. This sets certain things to the right settings, perhaps even some you don't have control over. After you boot with those settings, you can go back into BIOS and change the things you had before - such as Fan Failure warnings and Smartdrive on harddisks, etc... Don't put anything special in the MIT section - I'm assuming you haven't played with overclocking or other choices there.

    You listed everything but your RAM specs. Do so and check them to see what voltage they require. Your MB supplies 1.8V to DRAM by default, if they modules want more you need to supply it in MIT.

    Here's what I would do, long-term if necessary. Remove the graphics card and run off of the built-in outputs using the Radeon 4200 chipset.

    Oh, are you using the latest drivers for everything? Don't change the BIOS version, but get everything else.
    http://www.gigabyte-usa.com/Products/Motherboard/Products_Spec.aspx?ClassValue=Motherboard&ProductID=3143&ProductName=GA-MA785GM-US2H#s1

    Post here when you chk out these things and after running it a while without the vid card. I'll see when you post new stuff later so I can reply or someone else here will.

    Oh! The manual has specific instructions for adding vid cards - make sure you review those and have previously followed the steps.
  2. Mongo - I'm going to disagree a little with you here. I have the near-identical build also, without the video card.
    First question is are you overclocking? If so you need to come back to stock settings. The easy way to do that is to go into the BIOS and set to FAIL-SAFE defaults. That will turn it back to standard clock rates etc.
    And if DRAM is set to 1.8v that will be OK too. All DRAM is supposed to run at standard speeds (800, 667) at 1.8
    As stated the next option might be to run from the board video and take the card out. You need to get stability first and hopefully find what is causing the problem.
    Also what monitor size and resolution are you running?
  3. there is a recent BIOS update for your motherboard that came out at the end of last month. It says that it updates the BIOS with the proper CPU micro code for your CPU. Not correctly identifying the new CPU features 100% of the time can lead to failures during post. Maybe it will help since you CPU is newer than your board.

    here is the link
    http://www.giga-byte.com/Support/Motherboard/BIOS_Model.aspx?ProductID=3141


    you can also try GigaByte's @BIOS Live Update Utility found here
    http://www.giga-byte.com/FileList/NewTech/old_motherboard_newtech/tech_a_bios.htm

    this utility can automatically check for the latest BIOS and update it if you wish. Sometimes these utilities don't do it automatically like they should, so just use the first link to download the bios file and use @BIOS to update your bios with the file.
  4. DO NOT use @BIOS!
    http://forums.tweaktown.com/f69/bios-flashing-how-qflash-guide-27576/
    Quote:
    This cannot be stressed enough. I cannot recommend using it AT ALL with all other available options

    I have seen many Boards killed (IE: Bricked, that is your motherboard is now a brick and you will have to RMA your board) by using @BIOS. I would guess that more then 90% of RMA's due to a bad flash, were because of @BIOS alone.

    Yes it may work for you once or twice but if you keep using it you will find out the hard way it is not a good idea. Windows based flashing has always been looked down on and likely will never be a accepted or recommended method to flash a BIOS


    I often liken this to playing Russian Roulette... You might get away with pulling that trigger once, and only hear a 'click'... You might get away with it a second time, too... But by the third pull, the odds are starting to catch up with you - you keep on pulling that trigger, you WILL blow your brains out!
  5. SystemPat said:
    Mongo - I'm going to disagree a little with you here. I have the near-identical build also, without the video card.


    SystemPat,
    No disagreement at all! I failed to think about OverClocking - and I mentioned an "artifact" which is a term most often used when seeing errors from OC!!! Absolutely clear out the overclocking - all of it, RAM, CPU, bus. I would suggest the Optimized Defaults - they seem fine for all uses. (SystemPat, have you tried the Adv BIOS features? Press Ctrl-F1 after entering the BIOS. Nothing too exciting though.)

    ThisIsMe,
    Good spotting on that BIOS update. It's not actually needed for Phenom II 550 BE, mine's fully supported by F2. I've been leary of installing it because it might bow to AMD's pressure to disable the unlocking of X2/X3 cores. But I really should try it myself, just to see if it does anything. But, updating the BIOS is a good idea when having odd problems with a new build.
    -------------------

    bilbat warned about using @BIOS - here's how to update the BIOS without using it!
    One tip, do not flash your BIOS during a thunderstorm!
    http://www.gigabyte.com.tw/Support/Motherboard/HowToReflashBIOS.aspx
  6. Yeah. I did a quick edit and forgot to type out specs for ram.

    G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel

    I don't really mess with overclocking. I still can't reproduce the error. I've even done cold a few cold boots over the last few days to see if that did anything. I'm going to try the BIOS update and the optimized defaults. Do I run the AUTOEXE.BAT file or the FLASHSPI file for the update? I'm a bit paranoid about killing the board.
  7. bilbat said:
    DO NOT use @BIOS!
    http://forums.tweaktown.com/f69/bios-flashing-how-qflash-guide-27576/
    Quote:
    This cannot be stressed enough. I cannot recommend using it AT ALL with all other available options

    I have seen many Boards killed (IE: Bricked, that is your motherboard is now a brick and you will have to RMA your board) by using @BIOS. I would guess that more then 90% of RMA's due to a bad flash, were because of @BIOS alone.

    Yes it may work for you once or twice but if you keep using it you will find out the hard way it is not a good idea. Windows based flashing has always been looked down on and likely will never be a accepted or recommended method to flash a BIOS


    I often liken this to playing Russian Roulette... You might get away with pulling that trigger once, and only hear a 'click'... You might get away with it a second time, too... But by the third pull, the odds are starting to catch up with you - you keep on pulling that trigger, you WILL blow your brains out!

    Thank you. Saved me from saying that.

    Quote:
    All DRAM is supposed to run at standard speeds (800, 667) at 1.8

    That is not entirely true. In some cases, RAM just refuses to work at 1.8v, esp those RAM that need 2.1v to run at DDR2 800 such as the Crucial Ballistix Tracer. or ie: http://www.newegg.com/Product/Product.aspx?Item=N82E16820144240&cm_re=DDR2_800-_-20-144-240-_-Product
  8. That is very odd. Loaded defaults. Did the BIOS update. It still says F2 at the top and not F4. It did say AMD something changed down by the DMI Pool verify section.


    Update: Updated BIOS a second time, and it still says F2 at the top.
  9. Shadow,
    Good to know. My experience and what I've seen on forums is limited to the RAM dropping down in speed when it is given 1.8V and wants more. Of course, if they're gonna put LEDs on RAM, the 2nd most sensitive component the user can mess with...

    1vs1,
    Come on, break down and tell us if it's the Pi or the other model! F2-8500CL5D-2GBPK or F2-8500CL5D-2GBPI
    I'm using Pi myself, but I got their F2-8800CL5D-4GBPI, a 4GB pair rated at 1.8V - 1.9V

    What we now know is that regardless of which ones you have, they want either 2.1V or 2.0V - 2.1V --- really both rated at 2.1V. This is likely the source of the problems you're having. Your motherboard (also mine) is putting out 1.8V if you haven't changed it. And it maxes out at 2.1V. That's not good, because even if it "works" at 2.1V it might work better at 2.2V and you can't supply that.

    My suggestions depend on whether you can still return this RAM. If you can, I'd do so and choose some that works with 1.8V - 1.9V.

    Here's what is likely happening on your computer now. When it boots, it'll show the speed of the installed RAM, as the BIOS and POST see it. Right now, it likely says 800MHz. That's OK, but we'd like to see it showing 1066 - since that's what you paid for in buying the RAM. (If it works at 1066 we can explore the pros/cons of running it at 800 instead)

    First step is something you should always do with a new system. Set the BIOS to Optimal Defaults. This may alter some things you've changed but it also makes sure you're starting from a known good configuration. Do that and Save & Re-boot and go back to the BIOS.

    Go to the MIT at the top. Move down to System Voltage Control - should be on Manual, if not, change it. Choose DDR Voltage and change it to +0.3 - that'll be in red to warn you it's a major overvoltage. Save the settings and reboot - note the speed shown for the RAM. If it's now 1066, we're making progress. Go back into BIOS.

    BTW, Memory should be set to UnGanged, works faster.

    If the RAM showed as 1066 then next step. If not, choose Memory Clock and manual. Then set it to 5.33 - Save and re-boot!

    Now test your system. If the memory test on POST shows 1066 and we know it's getting 2.1V then it should work now.

    ----------------------
    Again, I recommend returning the RAM and getting 1.8V - 1.9V modules. If you ordered this RAM as a package with the motherboard, then they really should take it back w/o a restocking fee - as it's not well-suited to the board. And when choosing new RAM, look at both 1066 and 800 RAM - I'm using my 1066 RAM at 800 because it runs faster that way.

    Here's the exact memory I have and like. Also by GSkill but lower voltage. Also 4GB so not the same as you got.
    G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1100 (PC2 8800) Dual Channel Kit Desktop Memory Model F2-8800CL5D-4GBPI
    http://www.newegg.com/Product/Product.aspx?Item=N82E16820231194

    I run mine overclocked 800 @ 4 but regardless it's good RAM and well-suited to our motherboard. Others are too, but consider only those showing less than 2.0V.

    G.Skill doesn't seem to offer 1.8V-1.9V in 2GB kits at NewEgg. They should and might have elsewhere.

    If you do shop for new RAM, remember lower CL is good. And ask me about un-locking the other cores in that CPU after you get everything running well.


    This little guy lives in my computer now.
  10. I have the F2-8500CL5D-2GBPI model. I'm going to return the these, and go for the 4GB modules you have. The ram is less than 2 weeks old. I really had no idea about voltage requirement for ram modules.
  11. Sounds good. Remember if you're running Win XP or any non 64-bit Windows, you'll only have about 3GBs of RAM available. I have my RAM allocation to video reduced so I see 3.25GB, but for most it's under 3GBs. Still, it's the only way to get that much.

    If you have Vista 64 or Win7, it's not an issue.

    Good luck and let us know how things work out.
  12. I may try the BIOS update later today and let you know what I find out. Again, the shipped version F2 works fine.
  13. Yeah. Please do. I hope that I didn't mess that up. Every BIOS update I've done on previous machines actually showed the revision number after I was done.
  14. Hmm. Mongo, I tried you .003 voltage increase suggestion. Oddly enough, I got the error upon reboot. However, I can't reproduce the error again. I went back and forth several times with the settings. I also noticed it stayed at 800mhz. Was it the RAM or a cruel coincidence?

    On a side note, my friend was saying that the RAM's timing is set by the SPD. It sets all the timings and voltages itself. He said it should run fine at 1.8v at reduced timings since its parts of the specs. This is getting confusing.
  15. Your friend is wrong for a couple of reasons. One thing is that 1066 mode isn't a JEDEC standard but uses the EPP. So the SPD data isn't always read properly.

    RAM's timing can be set by the SPD, but not the voltage. For me, when I had the 2.1V - 2.2V RAM it put out the same voltage (1.95) as it does now when set to Auto. And it thinks it's putting out 1.8V so I don't know whether the 1.95V is real or not. If I set the DRAM voltage to +0.1 it shows 1.9V in every monitor program. And at +0.3 it shows 2.1V. I recommend both CPU Hardware Monitor and CPUz, available free at cpuid.com for normal diag use.

    Once you set to 2.1V, if the mem comes up at 800, you can try setting the Memory Clock to Manual. Then reboot. Go right back in and set it to 5.33 and reboot. (I do this in two steps as my system has hung a couple times when I change to Manual and set the ratio on same step.)

    If the memory now shows on Boot as 1066, then it's working. If not, it likely really wants 2.2V to achieve performance.

    I'd say the lack of errors IS due to the setting of voltage to 2.1V
  16. 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'm still wondering why my BIOS still reads version F2 though even after flashing twice. Mongo, tell me if your version stays the same after the update assuming you do update.
  17. Uh oh...

    If your hard drive was formatted or Windows installed with AHCI and you use it as IDE - or vice versa, it will cause errors including no boot.

    Read here
    http://en.wikipedia.org/wiki/Ahci
    and here to see what used to be in the article which is helpful for those with problems.
    http://en.wikipedia.org/wiki/Talk:Advanced_Host_Controller_Interface

    Pro AHCI - allows hot connecting and some other things.
    Con - seems much simpler

    Did the memory show as 1066?
  18. Yeah. I didn't pick IDE. It boots up normally. I get the whole YES or NO option when I load up my default settings, and I hit N every time. If I don't I end up getting a boot loop, and my machine keep rebooting at the Windows splash screen. That whole process made me realize that tapping a key in rapid succession or holding any key down for a long amount of time during POST would trigger the "N" error.

    Memory did not show at 1066. Either way I'm still getting the RAM modules you have. The last thing that is left is the BIOS mystery.
  19. Download CPUZ. Tell us what that says for the BIOS version. Glad it's fixed now.
  20. It says: Brand: Awards Software International, Inc
    Version: F2
    Date: 6/22/2009

    Definitely not the newest version. If the BIOS update didn't apply, did I do damage to the system? I thought if updates fail then the board is unstable or damaged.
  21. OK, I just updated to F4 without any problems. As expected, it reset all my settings to default, so first step was to choose Optimal and reboot, change some more, etc...

    Did you have those changes? If not, then didn't update the BIOS. Go over the procedures for updating from within the BIOS again, from floppy. I actually did it from a thumb drive I had set up with all the different BIOS versions.

    I downloaded the "from America" one - this is the link
    *** Don't click link unless you want the file to save ***
    http://america.gigabyte.com.tw/FileList/BIOS/mb_bios_ga-ma785gm-us2h_f4.exe

    BTW, I didn't notice anything different in the BIOS or avail settings.
  22. I got it to work finally. Do these boards have dual BIOS? If so, how does the second BIOS start up if one fails or gets corrupted?
  23. Most GB systems come with a feature where a 4 KB "boot block" program is included as part of the BIOS. This is a tiny piece of code whose job it is to recover from a situation where the BIOS code is incorrect or corrupted. It will attempt to load the backup BIOS, and, failing this, the boot block will try to recover the BIOS code, usually by reading it from a specially-prepared floppy disk. You have to have a floppy, and it must be first in your boot order for this to work. I have experienced three BIOS failures - two from attempting to burn the same corrupted BIOS file, as I couldn't believe the file could be corrupt, and still pass the checksum verification! The 'backup' BIOS has always 'kicked in', and reverted me to the 'as shipped' BIOS. Always makes me wonder what the deal is with @BIOS - how it can manage to trash as many boards as it does - all I can figure is that @BIOS is capable of scrambling the boot block itself, in the process of trashing your BIOS!
  24. ^Exactly right! It flashes the boot block by accident (or so I hope) and compleately kills the board.
  25. Mongox said:
    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.
  26. 1vs1comp said:
    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!!!
  27. 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.
  28. Mongox said:

    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.
  29. 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.
  30. 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.
  31. 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.
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