BIOS recovery tips (updated topic)

[Ruslan]

Since my original topic once again disappeared after updating these forums to the new UBB version, I decided to re-post my topic again with latest updates (because my original topic was more than one year old).

As I promised, this is my topic about BIOS recovery - thanks to forum members, who saved all my BIOS recovery topics, and sent them back to me, so, I do have them all again.
My topic is for experienced techies only, so, I think, here is the best place to post it.

My topic is about "how to" revive motherboard after failed attempt of updating BIOS, especially if motherboard won't boot at all after that bad flash (!). Materials, placed here, content some of my "know-how", and cannot be quoted without reference.

Why seemed to be simple BIOS updating operation can be finished with undesired result - motherboard, what won't boot at all?
Reasons can be different here:
1. You have downloaded wrong BIOS image file. Rarely, but sometimes manufacturers places wrong BIOS updates for their motherboards on their www-sites.
At least, once I had been surprised to see BIOS string message "P2B-F" after downloading and updating BIOS for my ASUS P2B motherboard (it was German ASUS FTP). Filename was correct - listed as for P2B, but it turned out be wrong file's content.Fortunately, both of motherboards are having almost compatible BIOSes.
But I've seen also quite a few BIOS updates for Gigabyte motherboards, what aren't working at all.
So, be careful here...
2. You forgot to unzip archived file - unbelievable, but sometimes it happens...especially with "dummies".
Many (if not all) BIOS updates placed on manufacturer's sites, are being packed using ZIP or another archiver.
So, You have to unzip the BIOS image file first before flashing.
3. Power surge or cut-offs during flash operation. You should have either UPS, or at least reliable PSU ; although flashing BIOS takes not so much time, but nevertheless, "be on safe side of caution";
4. Flash utility did not recognize BIOS chip correctly.
Make sure what flash utility does recognize You BIOS chip type correctly (!); otherwise You can fry Your flash IC!
Some of an old flashers (for example, awdflash ver.5.35) can recognize new types of flash ICs as 28F010 or 28F020 flash (i.e. with 12V programming voltage(!)). If Your BIOS chip is in fact flash IC with 5V programming voltage, Your BIOS chip will be damaged! So, make sure Your flash utility is fresh enough and supports BIOS chip type.
Some of motherboards are having special jumper for changing programming voltage (either 5V or 12V DC) of the flash IC. Make sure You have set correct voltage!
5. Sometimes new BIOS file can have incompatible with original boot-block. That boot-block (can be hardware protected or software protected) is responsible for booting motherboard even if rest of flash chip is erased or damaged (for example, after Win95.CIH virus attack).


New versions of awdflash utility by default does not support reflashing boot-blocks. That's the main reason, why seemed to be successfully done flash operation sometimes can turn out what motherboard won't boot at all!- an old boot block can be incompatible with new BIOS update.
Besides that, in some motherboard that boot-block can be hardware protected (as shown on picture above).
Sometimes boot-block survives and You can hear some booting sounds from speaker, and PC trying to boot from floppy. It is the easiest situation for BIOS recovery, though.
6. Of course, sometimes flash chip itself can be damaged. There are could be few situations...
Chip can have few bad bytes, what can't be correctly re-flashed.
Or have lost two manufacturer's ID bytes written into first two bytes (hidden) in chip. Can be activated only by applying programming voltage to the A9 adress line of the chip.
In last case You can see message "unknown flash type", and that chip cannot be re-flashed using ordinary methods.
It could be also simply an old flash utility what unable recognize new type of flash IC - use the latest possible one instead...
7. Current version of BIOS flashing utility can be working incorrectly with some flash IC types.
For example, I've seen too many failed BIOS updates after using ASUS flash utility (aflash) version below 2.02 and Mosel Vitelic 29F002T flash ICs. It turned out an old versions on Aflash utility are working incorrectly with those chips ... although flashing seems to be successful, flash operation has undesired effect -motherboard won't boot after that. Newer version of Aflash (2.02) utility have no such problem.
8. Some of flash ICs may be not supported by that particular motherboard's chipset ... it's definitely engineer's fault.
You can refer to .doc for Uniflash utility for some details.
9. Using Winflash utilities also can be risky - programming flash IC types requires precision timing, what hard to get in multitasking environment. Some programs can interfere with working winflash utility (antivirus, spyware, and so on).