NP900X4C BIOS Reset Gone Wrong

I recently tried to reset the BIOS settings in my Ivy Bridge Series 9 (NP900X4C-A01US) by unplugging the CMOS battery, and now it doesn't seem to be passing POST - I just get a Samsung logo and the BIOS progress bar, then it turns off and tries again. Same result if I remove the SSD or either of the RAM sticks, so I don't think it's a bad OS or bad RAM.

Is there a known way to get this thing back to factory settings, or am I going to have to replace the motherboard?

(And before someone asks why I need to reset the settings, it was to disable fast BIOS. I was running the Windows 10 preview and needed to downgrade to Windows 8.1 for an application, and I wanted to disable fast BIOS because I couldn't seem to mash F2 quickly enough to get it into the settings screen)

 

Hello wiley, welcome to NBR.

In addition to just unplugging the CMOS battery, you can try the procedure described in this post, which sometimes has been known to work. For best chance of success, I would unplug the CMOS battery again, AND disconnect the main battery (either by gently poking through the hole in the bottom to push the disconnect switch, or by physically disconnecting it). Of course unplug mains power as well. Then press and hold the power button for a minute.

Admittedly, we did have one member who reported that this procedure broke his laptop (in that same thread) but many others have tried it, and mostly it either does nothing or, occasionally, it fixes the problem.

If that doesn't work, the only other fix I can think of (except an expensive motherboard replacement) is to have someone with an EPROM burner re-flash the BIOS. You can use isosunrise's rollback guide here to locate and download the latest BIOS file for your model.

 

I tried this with and without the CMOS battery connected, and it doesn't seem to have done anything. I found a blog post earlier where someone mentioned they reset their Series 9 BIOS by leaving the CMOS battery unplugged for 48 hours, so absent anything else to do, I'll probably try that before sending it back to Samsung (or just ordering a motherboard from them - I'm still considering whether the savings are worth the chance that I'd screw up installing it).

Re-flashing the BIOS from an external burner sounds like it's probably too ambitious for me. Has anyone done that successfully in the past?

 

Do you have any other RAM to try?

I thought a BIOS update had bricked my X4C and put back the original RAM (which I had changed to some 1.35V RAM) ready to send it in for repair. However, with the original RAM the computer came back to life.

John

 

I'm still running the factory RAM, which is 2 4GB DIMMs. I did try removing one, then the other, then both. It obviously didn't boot with no RAM - I was wondering whether "not booting" would be the same BIOS loop or just a black screen, and it was just a black screen. Removing either DIMM didn't change anything.

I don't have any other compatible RAM sitting around to try, unfortunately. Given the timing, though, I suspect the odds of both DIMMs failing at the same time I opened the case to remove the CMOS battery are remote.

 

Next see this thread which is our most recent discussion about resurrecting bricked Samsung notebooks and includes a procedure for clearing the NVRAM. There might be something relevant to your problem.

John

 

A few have reported successfully doing this, such as member 2000br here. It is not many, though, since it requires equipment (the EPROM/EEPROM writer), skill, and desoldering the EEPROM on the motherboard (at least on some models). Certainly this is the last resort, short of replacing the motherboard.

If you can make the computer boot anything at all, the thread linked by John may have a rescue for you. Check post #7 there. Basically you create a WinPE USB stick (compatible with your computer's UEFI setting), then remove the SSD (to force booting an external source), and use that WinPE to clear the NVRAM (using tools from the BIOS update for your model).

 

I read through that entire thread, but I don't think it can help me. I never get to an OS at all - the laptop boots through the BIOS, then turns off (blue power light turns off completely), then turns back on and does it again. Removing the SSD and inserting a flash drive has no effect, so I don't think it's actually getting far enough to boot the OS. F2/F4/F10 have no effect as well.

After 48 hours with the main battery and CMOS battery disconnected, nothing has changed. At this point, I'm trying to figure out whether I'm better off ordering a motherboard myself or just handing it off to Samsung, and Google isn't turning up many reports of their service costs. Has anyone here had to have them fix this kind of problem before? What are they likely to charge on top of the cost of a motherboard?

 

Since the cost of having Samsung replace the motherboard is probably quite high (though I do not have any figures) I would look for a local repair shop with the ability to re-flash your BIOS chip -- as previously discussed. The guide here can help you download and extract the latest BIOS file for your model, which you can then give to the shop.

In order to locate the latest BIOS version, you need to know the three-letter ID of the BIOS family used on your model, which depends on whether it came with Win7 or Win8.

@John: Can you help with those IDs for the NP900X4C variants?

 

So... I was packing up the laptop just now to haul it to a repair shop and see if this kind of thing would be feasible, but before I put it away, I tried plugging in a flash drive made with this Microsoft tool to see if it would do anything interesting.
(that link is actually quite useful - it's basically Microsoft making Windows 8.1 installation media available for free)

To my surprise, it is now running the Windows 8.1 installer. I'll have to do a bit of investigation as to how I managed to miss this, because I did try plugging in bootable flash drives before. My current guess is that I didn't manage to properly create a UEFI-bootable flash drive. I was using Rufus, and I did explicitly try to make a UEFI boot drive, so I'm not sure where I went wrong. It's also possible that the opposite happened - clearing the BIOS settings by removing the battery may have reverted the machine to BIOS mode, but with no setup utility or boot menu to confirm it, I kept plugging in the wrong boot media.

Regardless, thanks for linking so much information on these BIOS issues. It sounds like the first step after install will be to force a BIOS downgrade/upgrade.

UPDATE:
The machine won't reboot into a fresh Windows install. I guess this means I have to try flashing from WinPE.

UPDATE AGAIN:
I'm still getting Windows back up on this machine (probably going to go with UEFI boot again, but avoid multibooting Linux), but here are some notes for anyone who has to run through the same procedure:
- The WinPE images mentioned in this thread will work, but you need to use Windows 8, not 8.1. Samsung's BIOS update utility (shown here) will refuse to operate under Windows 8.1, and the WinPE image doesn't seem to handle compatibility mode properly (all the UI elements for it are missing and even a manual registry entry for the exe didn't seem to work)
- The BIOS update will unpack as described in the other threads, but the flashing utility is SFlash, not one of the ones that's mentioned. My command line was "SFlash64.exe -v -sd -cvar -file P07AAC.rom" (v for verify, sd for skip version check, cvar for clear UEFI variables, and the ROM file). The -cvar is the key - without that, nothing will change.

 

You are probably encountering residual issues with trying to run Windows 8.1 on a machine (in particular the BIOS) that was designed for Windows 7 and where Samsung roughly fudged things to get Windows 8 to work. That fudge is likely to deliver more headaches now that M$ is doing its best to get all Win 8 users to upgrade to 8.1. In case you aren't aware, Samsung found it necessary to create a new BIOS (P**ABK) to get the X4C to work properly with Windows 8 but the extent of the changes was such that the updated BIOS isn't interchangeable with the P**AAC BIOS.

Anyway, one way or another, we are accruing a useful respository of knowledge about the fixing of Samsung's BIOS problems.

John

 

By "not interchangeable," do you mean Samsung was loading ABK onto new machines, but existing owners are stuck with AAC?

Would I be better off just sticking to BIOS boot, or is it worth it to try to get UEFI working again? As far as I know, the only benefit of UEFI on this machine is that the boot is a bit faster. Is there anything else?

 

Yes, the notebooks that were shipped prior to Windows 8 release came with the AAC BIOS then Samsung discovered that they needed a new (ABK) BIOS to work properly with Windows 8.

I would keep away from UEFI unless the notebook was shipped with UEFI enabled. While the final (P07AAC) BIOS seems to have fixed most of the issues you only have to read this thread to see what hassles people have had. Plus some new problems have appeared because Microsoft are forcing Windows 8 users to upgrade to 8.1 which has revealed some further deficiencies in the older BIOS.

John

 

After posting the question, I actually got Windows booting with UEFI and I'm now posting from the laptop. Unfortunately, I've now noticed that F2 is broken again. I'll have to see if I can repair that - if not, I'll probably have to revert to BIOS.

I was dual-booting Linux at one point but I stopped a few months back. I suspect my troubles started there and I just never noticed until now.

 

I am late to the party here, but to repeat John's advice, I would ONLY use UEFI on models originally shipped with it enabled and ONLY on Win8.x installations. For Win7 installations I always recommend BIOS/MBR on Samsung laptops.

The fact that your CMOS/NVRAM is easily corrupted (causing you to lose F2) is a sign that you have a BIOS that is easily disturbed in UEFI mode, which is a classic symptom of the tweener generation of Samsung laptops (designed for Win7, adapted for Win8).