Original Xbox EEPROM replacement

Hi all, i have an original xbox 1 with a bad EEPROM chip.

Basically when i turn the machine on it just flashes the eject button red.
I got round this by flashing the TSOP with an embeded EEPROM image but after some playing around last night and reflashing with an updated bios i've managed to kill it.

I have one of these serial EEPROM readers and have used ponyprog to try and write my backup copy back to the chip, which i've done many times before with different machines, but it fails everytime. I think i need to actually replace the chip on the motherboard but i cannot read anything on the top of it.

So i'm asking if any of you guru's out there knows what the chip is and point me to where i can order one or if anyone has a 1.0-1.5 motherboard thats dead if they wouldn't mind de-soldering the eeprom chip and sending it me, i don't mind paying.

Just one point to clarify, am i right in thinking if i purchase a blank chip and solder it in place i can then just hook up my eeprom reader and write my backup to it using ponyprog or does the chip need anything doing to it first?

i've got 4 xbox's here with dvd reading problems, you're welcome to one for postage and make one of the two.

Hi Amigafanboi, thanks for the offer but i'll hang for a little while see if i can get any joy on the actual eeprom chip. But i may come back to you later if thats ok.

Thanks

Mike

No probs :)

I think on the earlier Xboxen it was a 29f080 8 megabit TSOP-package EEPROM, 70ns. This chip was over-capacity :)

They later reduced the size; before there was enough ROM to hold 4 different BIOSes, you could even hook up wires and switches to change banks. Then they reduced it to 2 megabit, enough for just one BIOS.

How about this site? :)

Xbox 1.0-1.1 (8M)
http://www.swaytech.org/product_info...products_id=34

Or 1.2-1.5: (4M)
http://www.swaytech.org/product_info...products_id=33

You could even get a socket:
http://www.ap-products.com/sockets.htm - p/n 980020-40-01

The 4Mbit TSOPs in the 1.2+ Xbox are only 32pin I believe, but the range of sockets only start at 40 pins. People on forums etc. have just used these oversize sockets and offset the chip within them accordingly, there's apparently plenty of room on the mobo to accommodate them.

Hope that helps. :)

Alternatively, install a hardware modchip, which will override the Xbox's use of onboard flash. Once it's booted up and running, remove the modchip whilst the machine's on (diverting access back to the onboard flash) and try to re-flash the BIOS using EvolutionX booted off a disc. That may be much, much easier than desoldering the flash. I'd have thought it unlikely for the actual flash chip to be dead and may be worth a shot (what, 6 wires? compared to 32-40 TSOP SMD pins :))

Eg. this one: http://www.modchipworld.co.uk/store/duox-2-p-170.html

I have a spare modchip and all the stuff required to do this if you'd like me to try this method. It'd also confirm whether the Xbox board still works everywhere else.

Hi d0pefish and thanks for the very informative answer.
Its not actually the TSOP chip thats at fault its the eeprom (the little 8 legged chip) which stores the HDD info.

I'll upload a quick pic to show what i mean.

On the other note about flashing the TSOP while booting off a modchip, i've tried this in the past, on a completely different machine, with an xecutor modchip and unfortunately it disables the onbpard tsop upon boot so when i remove the modchip it won't allow me to flash the tsop.

Ohhhh, bugger - I do apologise, yes, that's the one that holds NTSC/PAL settings and other configuration bits. Damn!

From some pictures I've seen its a 24WC02 at least on one revision. Seems like a difficult to source chip - maybe your best bet is a donor Xbox after all :(

At least it sounds like you have a backup of its contents, that's what's important.

Some BIOSes allow the machine to boot despite a corrupt EEPROM, like X2 5035. I think Cromwell allows to reflash corrupt EEPROMs from a backup.

So, if you have an EEPROM bin file, you could use this with a modchip to attempt recovery:
http://arisme.free.fr/Xbox/Reflash/

Edit: Argh, re-reading your first post, it looks like you tried this earlier - sorry if you're already aware of this :(

i'll have a look into the cromwell but i'll have to dig out my xecutor modchip again, i generally don't use it when i can flash the tsop and be done with it. i generally just keep it as a backup.
Might have to take up Amigafanboi on that donor though.

Spares are always good!

I'm actually looking for a donor motherboard to attempt a RAM upgrade on my Xbox. Would I be allowed one of the dead Xboxes you have, Amigafanboi? :) :bowdown:

I reckon it's worth one last shot - make a Cromwell image using that site, the tools on it and your EEPROM .bin if you have it handy, and put that on one of your modchip's banks.

It shouldn't take too long to try out at least, and would be interesting to know if it worked :)

I will definately attempt it tomorrow buddy.

Stupid part about it all was it was working earlier tonight and i was only flashing the tsop because i was intending to sell it but it was my daughters and i'd customized the startup logo to be bright pink and say her name so i was trying to restore it to some sort of normality :lol:
I actually knew the eeprom chip was dead too and i just forgot to embed the eeprom image into the new bios.