Question BIOS Chip Identification Quick Question

[tomase]

Hi guys!

I'm restoring a barebones HP ProBook 455 G3 to life, but I'm having serious trouble with my BIOS chip on the motherboard. I'm used to dealing with bigger PCs, not things that small. Anyway, I need to flash the BIOS (and update it eventually, since the stock board has an AMD chip and there's a BIOS update floating out there).

But I have run into an embarrassing first. I can't actually *find* the BIOS chip!

There are three candidates, and I know it's definitely one of them, but two are devoid of text at all, and the other is so tiny that every magnifying glass I've used has failed to make it readable. I've looked everywhere for specs on this stock board to help me, and can't find a thing.

Images of the full motherboard and the section with the three chips zoomed in are attached below.

I imagine it is probably the chip next to the battery, but I don't want to fry the board by making a mistake. All three have a dot indicating pin #1, so I couldn't even use that as a process of elimination.


So, on to Problem #2:

EDIT: Nevermind, just going to use Linux.

Thanks in advance. I've been tearing my hair out for quite a while with this.


EDIT 2: Thank you to user Steltek for advanced specs on this board! I looked everywhere and couldn't find them! Now I just have 100 pages of programming lingo to wade through to see if it'll give me an answer.

If someone can still eyeball the chip, though, I'd love you forever.

 

[zir_blazer]

I suggest you to ask in a more specialized community like Win-Raid or any related to Coreboot, since few people knows about those things here.

Also, it may be possible that you have TWO Flash ROMs, even of different sizes, like in the Thinkpad X230, which had a 8 MiB + 4 MiB ROMs since it seems to have been cheaper than purchasing a single 16 MiB chip.

 

[tomase]

I suggest you to ask in a more specialized community like Win-Raid or any related to Coreboot, since few people knows about those things here.

Also, it may be possible that you have TWO Flash ROMs, even of different sizes, like in the Thinkpad X230, which had a 8 MiB + 4 MiB ROMs since it seems to have been cheaper than purchasing a single 16 MiB chip.

I appreciate your reply, thank you! I'm not accustomed to laptops/notebooks. I deal with bigger setups that aren't so cramped I'm not afraid I'll break something if I sneeze while holding it. 🤣

This motherboard has truly confounded me. I can find a dozen specs on the HP ProBook 450 G3, the 440, and all the series around it, but not a *single* one for this one. HP customer support was not helpful, and even after scanning in the serial number on their website, I couldn't get exact details. A replacement board is over $200, which is waaaay more than I spent for it.

Well, it has a good processor and 16GB of RAM that came with it, and I had a compatible SDD laying around, so if I can't salvage it I can always part it out. Right down to the screen, keyboard, and GPU. It'll be a disappointment, though, because I hoped to have a nice simple work laptop!

I will check those sources out. Thank you again! 😀

 

[tomase]

Well, I went to Win-Raid, and they're absolute jerks. Refused to point out the chip to me and hit me with computer science level technical specs instead and a "Good Luck."

I can just go back to Linux to flash the BIOS, that part is simple enough and takes care of Problem #2. But I'm still stuck not knowing which is the actual BIOS chip, and I can't try directly flashing a chip at random or I'll fry the motherboard. That's a $300 mistake I'd rather not make.

So I'm stuck. 😔 Crazy how I can build a rig from scratch, but hand me a laptop that needs a BIOS chip repair and I've basically inherited a brick.

I feel like an idiot. I have everything I need and the knowledge of how to do it, but I'm stuck because a bunch of people over on Win-Raid are just like, "Here, learn an entirely new branch of computer programming and you'll figure it out, we're not going to point the chip out to you." What happened to helping people? 😔

 

[Furious_Styles]

Here is the program for the flasher:

CH341a.zip

drive.google.com

Wish I could help you with which chip is the bios, but I'm not sure either

 

[Steltek]

Maybe this will help you to locate it (the download link is legitimate - I downloaded the file and scanned it, no malware):

HP Probook 455 G3 X73A DAX73AMB6E1 Motherboard /pcb Schematic Diagram pdf File Free Download | Final fixer

HP - HP Probook 455 G3 X73A DAX73AMB6E1 Motherboard /pcb Schematic Diagram pdf File Free Download This Schematic Diagram / Document PDF file Free will help you to trace Motherboard and track on board.

www.finalfixer.com

 

[DAPUNISHER]

Good on you for keeping it out of a landfill.

My best guess is it is the fat square one with writing on it at the bottom right.

Best place to get help is badcaps.net. They should have the right bios dump too.

The tutorial I have seen for programming uses a Raspberry Pi with ubuntu mate.

 

[tomase]

Steltek, that schematic DOES help. Thank you! I thought I'd looked everywhere trying to find that thing and just came up empty! Thank you so much!

Dapunisher, yeah, I'm going to ditch trying to use Windows and go back to good old reliable Linux for the programming part. I'm only using Windows on my spare laptop because I needed a program WINE wouldn't run a while ago, and I don't need it anymore.

Also, after more examination with my glasses on and a magnifying glass, I *think* that chip you referenced with the writing has the Intel logo on it. But that's still all I can make out (oh, to be 20 again with better eyes...).

Thank you guys for your help. I was getting so discouraged after working on this for so long and getting nowhere, but after a good night's sleep and waking up to your kind, helpful replies, I feel energized again! After my family festivities of the holiday today, I'll go on the attack again.

Thank you. Sincerely.

EDIT: I added truly zoomed in pictures with the three chips chips circled to the original post, just in case someone else wanders into this post and sees it.

 

[Steltek]

Steltek, that schematic DOES help. Thank you! I thought I'd looked everywhere trying to find that thing and just came up empty! Thank you so much!

Dapunisher, yeah, I'm going to ditch trying to use Windows and go back to good old reliable Linux for the programming part. I'm only using Windows on my spare laptop because I needed a program WINE wouldn't run a while ago, and I don't need it anymore.

Also, after more examination with my glasses on and a magnifying glass, I *think* that chip you referenced with the writing has the Intel logo on it. But that's still all I can make out (oh, to be 20 again with better eyes...).

Thank you guys for your help. I was getting so discouraged after working on this for so long and getting nowhere, but after a good night's sleep and waking up to your kind, helpful replies, I feel energized again! After my family festivities of the holiday today, I'll go on the attack again.

Thank you. Sincerely.

EDIT: I added truly zoomed in pictures with the three chips chips circled to the original post, just in case someone else wanders into this post and sees it.

I'm glad it helped. I'd never seen that website before, and at first glance it was just one of those websites that tries to trick you in and then charge you, or to spread malware.

Turns out though, it is a very neat website with a lot of useful information. I'm definitely going to bookmark it in the event I ever need it again for sure.

If you are still not sure about which chip it is, they have a contact button on the website which might be worth a shot.

Final Fixer - Computer Repair Forum Free Bios Board view Schematic

Final Fixer Provides Laptop and desktop motherboard Schematic diagram, Boardview and Bios file free of cost.

www.finalfixer.com

 

[SamMaster]

I found a picture of a Probook system board (claimed to be a 455 G3 but doesn't look like yours) and the BIOS chip was right next to the chipset, so prehaps the BIOS chip is hidden under the heatsink?

 

[DAPUNISHER]

I found a picture of a Probook system board (claimed to be a 455 G3 but doesn't look like yours) and the BIOS chip was right next to the chipset, so prehaps the BIOS chip is hidden under the heatsink?

That makes the most sense. Usually HP boards have it with a white background on the pcb, or a colored dot on it.

@mindless1 is probably the expert we need.

 

[mindless1]

I'm scratching my head wondering what has not been mentioned...

Why do you need to ID the bios chip? All I can guess (which is probably wrong), unless I wasn't following along closely enough and skipped over some details, is somebody took out the CPU that works with the current bios, put in a newer chip and it won't post until you upgrade the bios, but instead of just getting a compatible CPU to upgrade the bios, you want to do microsurgery to solder on wire to program it directly instead of booting to a bios flasher?

I can't tell which chip is the EPROM if any are. Are all the silkscreened markings the same, just a "U" with a number after it? In some cases the circuit can be traced but boards smaller than a desktop are very dense, may have more layers, and your picture isn't what I'd call focused if it weren't for these other factors making tracing the circuit near impossible, remotely. "Sometimes", you can use a better picture and tweak the saturation up and/or contrast adjustment in an image editing app to see the chip markings better, or a strong flashlight, at an angle so minimum light bouncing right back, and a magnifying glass and/or microscope.

However, of the chips you circled, one of them, not right next to the battery but just to the right of that one, does have markings I can see when the brightness is increased but I still can't make it out. A decent camera with a macro mode should be able to pull the chip markings, or back in the day I had good luck using a scanner, before they went to CIS sensing that is terrible at depth focus for 3D things. I am not suggesting that is the EPROM, just that you should be able to find a way to see those markings and either ID it or rule it out.

I may just be wasting your time because I'm clearly not up to speed on why you need the bios chip identified.

Anyway I looked at the linked PDF, it states socketed ROM which makes me wonder how applicable it is, but at least it shows it is an 8 pin chip. It shows it is a 6*5mm socket, are any of your chips that size? Since the chip isn't socketed, that bit of info may be incorrect. Without a socket, a different form factor could easily be substituted if planned for.

On that PDF on page 41, the "APU SPI ROM" table is what you're wanting, WND is winbond with 2nd column P/N
W25Q64FVSSIQ, datasheet:

https://media.digikey.com/pdf/Data%20Sheets/Winbond%20PDFs/W25Q64FV_Rev_S.pdf

and GGD is Gigadevice, GD25B64CSIGR datasheet:

https://www.mouser.com/datasheet/2/870/gd25b64c_v2.1_20200217-1668047.pdf

HOWEVER, these two are both just following the lead in the PDF that suggests a socketed EPROM which it isn't! ... unless a prior suggestion is correct and there is a socketed EPROM under a heatsink, but I am doubting that more modern builds would have a socket- but I could be wrong!

Without knowing your need or purpose, I'm not sure what direction to go in at this point, if I can help further at all. You can use the datasheet to see the pinout and check whether that aligns with what you'd read with a multimeter but I'm still not sure why you need to ID the chip at all, unless you had a specific event where you were certain that some ESD event fried the bios programming and not damaged the entire chip, and how would you know that is the problem until you already had ID'd it and found it was non-functional?

Or am I getting this wrong and you want to program a new chip in a programmer without using the mainboard then desolder the old chip and solder a new one on? I'm back to my opening statement that some important piece of info is missing or I just overlooked it.

Can you restate, concisely, what you are trying to do that needs the chip located?

 

[tomase]

Sorry, I haven't been online in a few days!

So, the previous owner tried to update the BIOS when an update was released and it did not go well. He was not super technical, but knew just enough to be dangerous (kinda like me, lol), so he ended up just pulling out the hard drive and RAM and selling them. I rescued/bought what was left.

I am trying to flash the BIOS with its original stock software to repair it. I attempted booting up every way under the sun, even a live Linux recovery USB, but that botched BIOS update has temporarily bricked the laptop. I have a compatible hard drive and RAM for it, but I need to get into a functioning BIOS interface for it to initially "see" it (or, that's been my experience with HP, at least).

Those schematics, after studying them, are not helping me. They are just far too technical for me, and I guess I'm just in over my head.

I will try to take better pictures, and see about peeling back the heatsink to see if it's hiding under there.

 

[VirtualLarry]

So, the previous owner tried to update the BIOS when an update was released and it did not go well. He was not super technical, but knew just enough to be dangerous (kinda like me, lol), so he ended up just pulling out the hard drive and RAM and selling them. I rescued/bought what was left.

I am trying to flash the BIOS with its original stock software to repair it. I attempted booting up every way under the sun, even a live Linux recovery USB, but that botched BIOS update has temporarily bricked the laptop. I have a compatible hard drive and RAM for it, but I need to get into a functioning BIOS interface for it to initially "see" it (or, that's been my experience with HP, at least).

Search the owners / support manual for "bootblock BIOS recovery". As long as the "bootblock" code is intact, but the "main BIOS" has a checksum error, it may be recoverable.

 

[mindless1]

Okay, so you have a "probably" corrupt bios, but it would be interesting what the event was, in case something screwy happened like the power socket was jolted and broken and no battery, and you're still trying to power up using same broken power socket.

Is there any sign of life, any POST starting on-screen?

I still don't understand what you hope to accomplish by finding the bios chip. I mean, that can be useful, if you have the means to program a different chip in a different system or on a special jig set up for the purpose, then swap the badly programmed chip with a pre-programmed chip, so is that the plan or you have something else in mind?

Besides that, definitely look into what Larry mentioned about bootblock bios recovery. If the owner's manual doesn't mention it (wouldn't surprise me for an OEM laptop), the general procedure is format a USB flash drive to FAT16, maybe FAT32, decompress the bios file provided by HP and dump the files onto the flash drive, and have it in when powering up the laptop. You might also need some utility to make the flash drive bootable, seems less likely on a semi-modern laptop but I don't know.

The tricky part is whether there is a certain combination of keys to hold in while powering up the laptop for example WinKey + B is one example, to get it into bootblock flash mode, then once in that mode and reading from the USB flash drive (easier to know if it has a flashing LED access light on it) you can release the keys, then it may need to sit for a small # of minutes doing its thing.

 

[tomase]

Well, I know just enough about these things to be dangerous, so... As to what I'd been hoping to accomplish, I'd wanted to try and flash the BIOS chip with its original software since the HP Recovery Utility and all the dozens of key press combos I'd searched for didn't work.

The good news is I found the chip! I had to teach myself to read that schematic, and how to read the cryptic markings on the OEM motherboard (Hey, it's always good to learn new things... I know a ton more about resistors and capacitors now). However, I don't know what in the world was done to this laptop, because no amount of reprogramming this chip seemed to work. My equipment worked, as I got a bin dump, but never solved it by flashing it.

Compatible BIOS chips are cheap on eBay, so I bought one in a final hurrah to try and make something work. I desoldered the old one, soldered in the new one, and now the laptop works great!

Did I go about this the hard way? Maybe. Probably. I don't know any other way because nothing was working. But in the end I learned a lot and my laptop is doing great.

Thank you everyone for your help. 😀

 

[DAPUNISHER]

Which one was it? On the underside? Don't hold out on us. And I was going to mention some of the Taiwan sellers on Ebay even help you id it, but I didn't want to ruin your fun.