Loopy BIOS

In May 2021, the motherboard I used for my computer went out of order. I saw a message upon powering it up. It said “BIOS Recovery Mode. Please use the renamer utility to initiate the recovery.” Well, it said something similar. The motherboard model is ASUS P8H77-I. Before this happen, the on-board graphics seize to show in the BIOS and I was using an add-on card for graphics. I think nothing of it because it was getting old that thought. This happened months ago.

Well, fast forward to February 2023 and figure that let’s find out what is going on with the motherboard and why it stated that error message. The error message can only be seen by using an add-on graphics card instead of the on-board graphics. If I use only the onboard graphics, I get a BIOS beep error that is related to no graphics card found. I did what the message said to do. I downloaded the BIOS image from the motherboard manufacturer and the renamer utility. Ran the renamer utility. Then I put the file on a USB flash drive. I used an 8 GB USB 2.0 flash drive formatted as FAT32, but not exFAT. I put in one USB port for the out-of-order motherboard. This did not work and I repeat this in all USB ports including the USB 3.0 ports.

What happens when a CPU first powered up?

I thought the BIOS could be corrupted because it will only show this message if the checksum run has failed. When 80x86 processors power up, it first accesses a memory address. In this case, the BIOS chip is that memory address. It runs this address as any program. This program seems to do a checksum on the data of the BIOS and it seems this checksum has failed. The reason why I can see the error message if I use the add-on graphics card is that the PCI Express slot is wired from the CPU while the onboard graphic is technically wired from the chipset through DMI. It seems the chipset does not have any basic programming upon powered up, so it requires the CPU to provide that from the BIOS. Since the BIOS failed checksum, the program stopped before providing the firmware for the chipset. This explains why the USB flash drive can not be accessed.

I got a bricked motherboard, but I got a fix it

I powered off the motherboard and use my other hobby skills such as electronics design. I used my digital multimeter to check the transistors. They all measure OK, so I move on to the adventurous plan of using a stand-alone programmer. Before this, I also measure the resistance from the pins of the BIOS to the PCB. They measure very, very low resistance which is good. For the ASUS P8H77-I motherboard, the BIOS is in a DIP socket, so removing does not involve a soldering iron. This makes it easy although I do know how to desolder and solder. Maybe another time for another motherboard. This motherboard is not working because the software in the chip is corrupted or damaged. I thought if I use a stand-alone programmer, I can probably fix this motherboard.

Copy Image, Verify, Erase, Verify, Write Image, Verify, Test…It is alive!

I got the stand-alone programmer to fix the motherboard. Even though the BIOS is easily removable, I still take precautions on how the chip is orientated in the socket. I know from experience that the dimple of the chip designates pin 1. Yes, there are silk-screen markings that state pin 1. Also for any questions, I took a picture of the BIOS chip in all its glory before removing it from the socket. I make sure the motherboard is completely powered off and I remove the chip carefully. I used a needle nose plier. Rocked the chip to ease the chip out of the socket. I did this several times on a breadboard. The trick is not to put too much stress on the pins chip. The rocking of the chip helps to release it from the socket. If done, the socket will seem it spit the chip out.

After I got the chip out of the socket, I put it in the stand-alone programmer. The stand-alone programmer came with the software. The software was on a CD-R disc, so I copied the software to a directory and scan it for viruses/malware. The scan report with no threats. I make sure the stand-alone programmer was connected. I loaded the software for the stand-alone programmer. When the program loaded, the text was in Chinese. I searched through the menu bar where changing language might be in. I found it where to change to English. After I did that, I closed the program and open up the program. The software automatically detected the chip that I put in the stand-alone programmer.

I would like to verify that the stand-alone programmer works. I copied the BIOS chip and verified that I copied it. The software said the image is correct. Then I selected erase. Next, I verify that I erased the chip. The software said the chip is empty. Then I wrote to the chip with the image I made earlier. I verified the writing process. The program said it is correct. I put the chip in the motherboard and powered up the motherboard. Yes, this is not the fix, but I want to verify if the write worked by making sure I get the same BIOS message. I did get the same message and indeed I did. I powered the motherboard and remove the BIOS chip.

Using the stand-alone programmer I wrote a BIOS file that got from the ASUS website for P8H77-I. The process that did this is Erase, Verify, write BIOS file, and Verify. All of this reported that this was successful. Put the BIOS chip into the motherboard. I first remove the add-on graphic card and make sure I have a computer monitor hooked to the onboard graphic. Then I powered the motherboard on. The motherboard came to life with that successful single beep if a speaker is connected to the speaker pins on the motherboard. The onboard graphic works and it is shown in the BIOS.

I put an operating system of my choice which is GNU/Linux and the ASUS P8H77-I works.