First post, by moonlight
I have an Micronics M55Hi-Plus Rev B board w/ Pentium 200 MMX CPU. It comes with Phoenix BIOS 4.05.10b. The BIOS flash is an Intel E28F002BCT120 2Mb TSOP40 flash chip that is soldered on board. I accidentally flashed the 4.06 BIOS file for Rev A and now it cannot boot. After power on it has a black screen. The PC speaker has one long and two short beeps and then the floppy drive (I use a Gotek floppy drive emulator) light is on. The speak then keeps beeping with a 3 beep pattern. According to some online resources, it means that the boot block is waiting for the recovery disk. I could not find the recovery disk for this board model. The closest I could find is a recovery disk utility for M54Hi board and one for M55Hi-Plus Rev D. All I could do was creating recovery disks and replacing the ROM files with the 4.05.10b file that I downloaded from https://www.driverguide.com/driver/detail.php?driverid=1206.
The M54Hi recovery disk found at http://ftp.mpoli.fi/pub/hardware/ROM/OTHER/ has three files: "BBCMD.COM", "BBDOS.SYS", "OLDBIOS.BIN". I replaced "OLDBIOS.BIN" with 4.05.10b BIOS file. When I used this disk, I could hear a beep and then the floppy drive light was kept on without any sound from PC speak. After several minutes I rebooted the computer and still could not boot.
The M55Hi-Plus Rev D recovery disk found at https://www.driverguide.com/driver/detail.php … driverid=161893 has four files: "MINIDOS.SYS", "BIOS.ROM", "PHLASH.EXE", "PLATFORM.BIN". I replaced "BIOS.ROM" and "PLATFORM.BIN" from the 4.05.10b file for Rev B. When I used this disk, I could not hear anything and then the floppy drive light was kept on without any sound from PC speak. After several minutes I rebooted the computer and still could not boot.
Does any one have experience with Phoenix BIOS recovery on Micronics M55Hi-Plus or similar boards? Online sources also said that Micronics uses a different boot block format so it is not compatible with other similar Intel boards. The boot block resides at the top area and as such no jumper is needed for recovery operations. The source website of those old recovery disks "www.firmware.com" does not exist any more so it is very difficult to get any information. Thanks!
Also I heard that even if you get a black screen out of PCI video cards, the BIOS boot blocks still support ISA video cards. I'm not sure if it is true and if my board has this feature as I currently don't have an ISA video card. If an ISA video card works I can at least get some diagnostic information of why the recovery disks failed.
The ultimate way if everything fails may be using a chip programmer to reprogram the Intel E28F002BCT120 2Mb TSOP40 flash chip that is soldered on board. Does any one have experience in programming this chip? I am a noob in hardware. Is it possible to "hot program" with a certain programmer and adapter? Or do I need to desolder it (with a hot air gun) to program and then solder it back? It sounds difficult as the chip is surface mounted with 40 tiny pins.
