So I got the T48 flasher but it doesn't recognize neither of the 3 BIOS chips I have 🙁

Checked id 0x FFFF is an invalid code AFAIK, it is not in the ID list that I have.
Are you sure that eeprom is a PM49FL004T ? Did you peel the sticker back and check ?
Are you sure that eeprom works ? What are the other two ID's ?

Yes, it is surely the PM49FL004T. The chip you see on the picture was pulled from an ASUS P4R800-VM that I use.

Maybe chip is just broken. Datasheet stands that this is 3.3v part. Did you tried to crossflash it in motherboard with 5V flash ?

Nope, the chip is the same. My P4R800 boots from it fine.

martin778 wrote on 2025-06-15, 10:48:

Nope, the chip is the same. My P4R800 boots from it fine.

Try disabling the "check device id" checkmark in xgpro and then try reading the bios chip again.
The contents should look like a normal bios. if it's all FF or 00 then something's amiss.

weedeewee wrote on 2025-06-15, 10:54:

martin778 wrote on 2025-06-15, 10:48:

Nope, the chip is the same. My P4R800 boots from it fine.

Try disabling the "check device id" checkmark in xgpro and then try reading the bios chip again.
The contents should look like a normal bios. if it's all FF or 00 then something's amiss.

Agree ! Since the Pin check is ok, try to read it. Being a Firmware hub it might have boot block write protected so ID cannot be read (should be 9D6E, PM49FL004T*PLCC32 PMC)
My only board with same PM49FL004 is a Giga i865pe based but eeprom is soldered, none of my other i865 based use same chip.

FF data on all 3 chips. I don't know, maybe this T48 is broken or the PLCC adapter is somehow defective...

Hmm, are all 3 a PM49FL004T ?
I just read a Winbond w39v040fa off a Asus P5P800 SE earlier using the plcc 32 adapter that came with my Xgeku, worked fine but is a diff eeprom chip.
The adapters that come with or from the genuine Xgeku website or their genuine Ebay store are all green, not blue AFAIK.
http://www.xgecu.com/en/ or their Ebay store: https://www.ebay.com/str/xgecuofficialstore (where I bought mine a few years ago.)

Yes, removed the sticker from the last chip, all are exactly PM49FL004T.

I bought the adapter elsewhere, maybe it's bad...I'll see if I can get the Xgecu adapter.

martin778 wrote on 2025-06-17, 08:08:

Yes, removed the sticker from the last chip, all are exactly PM49FL004T.

I bought the adapter elsewhere, maybe it's bad...I'll see if I can get the Xgecu adapter.

The expected adapter wiring/pinout is available under the View Adapter button in the Read window. No point in paying for another adapter if the one you have is a match and there are no obvious faults with it.

The pin detection function in XGPro is quite rudimentary. It basically only tells you if something is connected, not always if it's connected the proper way.

The ZIF socket they've used can be quite sensitive, barely visibly bent IC pins can cause trouble. Try sliding the adapter back and forth in the socket while applying pressure with the lever, it might help. Also, cleaning the pins on the PLCC32 package properly never hurts.

Generally those Xgecu programmers seems to work with just about anything you throw at them, however that being said, your chip seems to be a bit on the exotic side. I've mostly used my T56 with bog standard stuff like 25, 27, 28 and 29 series chips.

They are all 22+ years old chips. I've tried wiggling the IC in the ZIF socket and if the pin is bad, it will show a red X mark next to it. Tried a few times but always get only FF's.

I do wonder if I can just use a different BIOS chip on the board than this PM49 if the pinout matches.

martin778 wrote on 2025-06-17, 11:26:

They are all 22+ years old chips. I've tried wiggling the IC in the ZIF socket and if the pin is bad, it will show a red X mark next to it. Tried a few times but always get only FF's.

I do wonder if I can just use a different BIOS chip on the board than this PM49 if the pinout matches.

Have you tried upping Vcc Current Imax a bit? I believe the default setting is the typical value from the chip datasheet, hasn't always been enough for me with some chips.

You probably could, however, some BIOSes use a chip ID whitelist, and might throw errors during boot despite the replacement chip being electrically compatible.

Didn't help, sadly. All FF.

Inside many newer BIOS with ESCD you can hex edit and read which eeprom types will work with a specific BIOS+board.
Inside the P4P800 bios 1019 @ 0707F4 escd area is:
"SST 49LF004 FirmWare Hub. Winbond 39V040F FirmWare Hub. PMC PM49FL004" those are all compatible eeprom.
Probably why the Winbond 39V040F is used on many P5P800, same chipset and similar BIOS requirements.....
inside the p5p800 bios escd area lists: SST 49LF004A FWH. Winbond 39V040F FWH. PMC 49FL004T FWH. and Intel 4Mb FWH. ST M50FW040A FWH. ATMEL AT49LW040 FWH

You could try plugging your T48 into another USB.
Preferrably USB 3.0 (for power) and not the frontal ones (if you use PC).

My T48 \ TL886 often refuse to work correctly when plugged into frontal USB 2.0 ports of my PC.

Agree ! And find ANY bios chip in DIP format, off a motherboard or even off a ISA vga card, and try to read it. That will help figure out if the programmer actually is working...