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BIOS EEPROM Programming

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I recently bricked my laptop's bios and i have tried to recover it using floppy drive recovery method but it didn't work for me as its Boot Block is also corrupt. It is a phoenix Bios and i was thinking to reprogram its eeprom using an external eeprom programmer like from serial port or paralell port its number is mx 25L8005m2c SOIC but then i found out that my desktop also has the same kind of ic it is mx 25L4005apc P-DIP so i was thinking i could use a another same kind of EEPROM to try to reprogram that bios into a new blank eeprom by "hotswapping" technique then solder its legs to the laptop bios mount point by removing laptop bios chip and check if it boots up but the problem is that i have very little knowledge about eeproms so i need some help :confused: so if i could get some insight into eeproms and also need to know that can i substitute another ic, because where i live w25x80 and EN25t80 spi flash roms are available but would my desktop board support flashing a 8Mbit rom where as it has 4Mbit rom.

These are my doubts any help would be great.

Thanks in advance.
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I am thinking some computers have a flash bios with a backup copy. You can use the backup to reflash the working copy. I have never done it but expect that there is a jumper on the MB to activate the copy. Check the manual for you MB.

You're going to hot swap a running computers bios with a soldering Iron?
I see this ending well... You got balls just to suggest something like that =)

Why don't you download the ENTIRE PDF file for your eeprom and then a painful few hours reading the programming section and programming a micro controller to program the eeprom for you? It may be possible to in circuit program the eeprom if not too many wires are needed, you'll just need to find some way to get contact to those lines carefully.
The boot block of the bios is also corrupt so recovery doesn't work and it is a phoenix laptop bios for compaq v6604au so it doesn't have a recovery process other than boot block as far as i know.And the manual of the motherboard doesn't contain any info other than disassembling the notebook.

I live in india in a state called orissa and i am 4th sem elcetronic engineering student. I have tried to order a few pieces of the MX25L8005 ic and may be it could be available with in a week.

You misunderstood me i was saying that the latops ic is soic and desktop ic which is working fine is p-dip so i am not going to power the latop motherboard just remove the desktop's bios chip and insert a empty eeprom in its place and flash it using my laptop's bios upgrade utility and then remove the laptop's bios chip by desoldering it and connect this newly flashed chip to the laptop board and power it up andcheck whether it boots up.

But the problem is that the eeprom of the desktop board is MX25L4005 which is 4mbit but the eeprom of the laptop is MX25L8005 whcih is 8mbit and the blank chip that i am going to use for testing is En25T80 which is 8mbit. So i want to know that that would putting the test chip in desktop motherboard create any problems.


I just though, once the flash utility is running it shouldn't actually need the bios, in fact it can't need the bios because it reprograms it. So if you remove the chip from the PC while the bios flash utility has already loaded nothing bad should happen (test this first carefully) if that doesn't work then all bets are off.

It seems a little odd that they have the same bios but one is 4mbit and the other is 8, are you sure they are compatible? Also it shouldn't matter as long as the flash program doesn't try to read or write to a space that doesn't exist.
My laptop's bios is of phoenix and desktop's bios is of AMI so they both aren't compatible but the specifications of MX25L4005 and MX25L8005 are same except for the capacity as stated in their respective datasheets.

So i am going to use Uniflash program for flashing the laptop bios file on either EN25T80 or W25x80 by fixing it on the desktop bios socket.

Then remove it and solder to the laptop motherboard after removing the laptop's bios chip.

So would this procedure work, i mean will the desktop motherboard with originally 4mbit flash able to flash a 8mbit bios file to a 8mbit chip,or are the motherboards designed to work only with specific spiflash chips, I am quite confused at this point. So i think the best thing is it to try it out.

Here is a image of the laptop bios chip it isn't clear but atleast viewable:D


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Yeah, try it and find out is about all you can do.
Finally Success!

I have successfully repaired my notebook bios but hot flashing couldn't do it i just removed the chip from my motherboard then built the spipgm lpt based circuit for programming which i got hereRayeR's homepage/Programátor SPI FlashROM na paralelní port and finally reprogrammed with a bios rom backed -up from my friend's notebook who has exactly same bios with the help of this tool i have posted.

I hope this info would be usefull to someone.:)
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Congrats on getting the bios flashed, the bulk majority of people wouldn't have gotten that far =)
Well may be I Was Lucky this christmas because i am not quite a programmer and not a hardware level programmer at all but i just didn't lose hope when the service center guys said that they have to swap the motherboard and it was out of warranty, i just tried and tried many different tricks until i was tired and finally achieved success.

Happy New Year To EveryOne out there.
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