Thanks, I can possibly remove FPRR (Flash Protected Range Registers) setting causing that error, but you would need to program that BIOS to the board first before you could then later FPT flash BIOS region without that error 28.
So for now, only way to update a BIOS edit will be with the stock installer, which will probably need edited .dll or .sys files, depending on the error you get with modified BIOS (you'll have to show me once you attempt). Forgot you have programmer!
We can deal with this later if need be, once all is done, since this might take me a while to dig out and fix (It's done in assembly/disassembly)

I can modify BIOS no problem with Intel tools (And can make settings visible to you outside of Intel tools), don't need danovan6000 guidance, but asked in case you had something exactly relating to this specific system.
Before I make settings visible for you in the BIOS, I need a zip of images of all pages of your BIOS, so I can see what you see and don't double enable something to be visible. Please put those in a zip for me and I will make settings visible for you in next mod BIOS.

The BIOS below has settings adjusted as discussed previously (+ ME Re-Flash enabled & unlocked FD/always)
Here is all settings adjusted
FD Unlocked
ME Reflash (Disabled) >> Enabled
Internal Graphics device (Auto) >> Enabled
Always Enable PEG (Enabled) >> Disabled << Now, PEG/PCIE Graphics is disabled entirely
PowerExpress Setting (Muxeless Fixed Scheme) >> Muxed Fixed Scheme
Normal Boot Menu (Normal) >> Advanced

http://s000.tinyupload.com/index.php?fil...958798393857187

@jeroenvtec - All those settings can be made visible to you, once I have all images of your BIOS.

thanks I am on it!
for now I am stuck at 99% for the second time, but keep on trying :)

I attached pictures

Stuck at 99%, what's that about? Thanks for the images, will get on that tonight for you. Good luck in the meantime, hope your BIOS programmer stops hassling you. I will try to unlock FPRR for you, then you wont need that anymore!
Missing exit and main images....

small update, version 1.29 does reconise the chip ! and does the flash in 6 min , jiiihaaaa
but with the special rom the laptop did not post, tired couple of times with and without battery etc.
you can or may keep the protection in the rom, fine by me and a bit saver, I will only program via usb. thx

edit
caps lock blinking, i am out of tries so have to wait for your expertise :)
new bios images

New BIOS from post #16 does not work, are you sure it's not due to software 1.29? Did you write back working rom with 1.29 too after that failure?
Did you let it sit for 5 minutes or so with cap locks blinking? Just thinking maybe it was auto-recovering, but I'm not sure how RSA edited BIOS fail, I think when it's bad it just doesn't boot so this is not good sign for BIOS mod but see below lets test a few things before we assume this is it.

Thanks for images, no need to blur that stuff, it's all in your backup BIOS anyway

@jeroenvtec - Here is 5x new BIOS to test, this one with only single settings changed for now, made a few different ways so we can see if editing method is an issue or if RSA signature is the issue and no matter how the edit is done it's going to fail.
http://s000.tinyupload.com/index.php?fil...522675008355034

Please test each one, even if one works don't stop there, please test each and let me know outcome of each one.
No changes will be visible to you in BIOS, so no need to look for that, just test each and see if you can boot to BIOS or not, thanks

yes usewd also 1.29 to flash the working back, them cmos rest and it posts.
yes I know but you are not the only one :)

first bios file for the programmer also a black screen and blinking, could it be there is a ec or other chip ? can we deal with that aswell ? Ik will open it again to look for.
Now I will try the windows flashes.

thanks so far !

edit there is a other winbond chip at the other side 25X40BVSIG but programmer can't connect to it.
tried also other bios files found on the net but none will let the laptop boot .... only the org file and with unlocked dc

even when i go back to f12 from hp sp55375, all ok but when I flash http://www.bios-mods.com/BIOS/index.php?..._ByCamiloml.exe same black screen

No other chip matters, if none of those BIOS I sent work, then RSA Signature security is why it's failing each time. Did you test all five BIOS yet?

You may be able to "Flash in" those BIOS, any I made, or the Camiloml ones, all depends but I suspect those may be older BIOS. If there is MOD BIOS for unlocked menus' then it should be possible, since that is same area/module I edited for this one test change we are doing now.
Now, some HP were not RSA on old BIOS, but new BIOS are RSA signed. You will have to research that for your specific model, and if there is earlier non-RSA signed BIOS then we can do those no problem instead of the latest one.

What you can try once you are done testing them all, is to boot to grub and use setup_var instead to change the settings, that shouldn't cause any RSA failing security issues.
I'll show you how to do that later tonight.

ok I thought maybe some protection chip or dual bios

I flashed the two in the irf folder, no luck
via h2o tool I was unable to the flash the file, some error about the data

what a nightmare to flash a cool rom

@jeroenvtec - You have to try all five BIOS I sent you via programmer, including the three in the H2O folder, so we can be sure it's RSA not editing method causing this. Sorry if that H20 only confused you and you thought flash via Insyde tools only, that was more meant for myself to know which method was used

As for actual "Flashing" after that, yes, I expect there will be an error due to modified BIOS, either platform.ini will need edited or one of the dll or sys files (or both) and to do that exact error needs to be known to me.

Check very early BIOS version for this system, are they encrypted too? We'll have to change a setting via grub and see what happens, I bet that will be OK if you don't get an out of bounds error or something like that when using setup_var

ah ok
I only know that it was related to encrypted stock bios, but now also the latest version is fine to decrypt.

if I am done with flashing I have to make a usb stick with the custom efi file like you mentiod in the other topics ?

I have tried all bios files, none will post.
method:
connect programmer, detect chip, erase, blank, program, verify.
Then boot, reset cmos, boot again.
first boor fast caps lock blinling, turn off and on with ac takes much longer when blinking starts

I can reflash the old bios, I also succeed to downgrade to f12 via windows, that bios I also can read and program again.

I flashed one of youre files, disconnect programmer read it again, excact the same, but when I boot the system the file is diffrent, I attched it.

@jeroenvtec - File will change after startup, due to time/dates changing, and NVRAM variables will update/change, so it will always be different once you power it on.

Yes, I think we are done testing, unless you find old BIOS for this board that is not RSA Signed (You can tell by PhoenixTool, if it decrypts it, it's signed/encrypted)
Yes, time to next test changing variables by Grub / Setup_var, this should be OK method and not break the signature/security.

@Lost_N_BIOS Ok clear

I have now f12 running, I will attach it, I don't see any enrypted messsage at andy's tool, only with the bios.
What I don't get is there is a modded bios version of sp55375 witch is sp55375_UlkMenus_ByCamiloml but even that bios would nog boot.
on a archive site I have been able to read some and found this comment: (click)

"Some HP bios made between 2010-2011 only implement the RSA signature check in the flasher utility. This makes it possible to modify them.

However newer HP laptops also implement a signature check when your computer starts up. This makes modding these bios currently impossible. This will remain this way unless we get HP's private RSA key.

If your computer has moddable bios, then my tutorials will work for you. If your bios aren't moddable, then any modification to it will brick your laptop."

there is no auto recovery on the laptop I always have to flash it by programmer again.
So still not sure if I have intern rsa

This contradicts itself, what do you mean exactly >> "I don't see any enrypted messsage at andy's tool, only with the bios"

Those BIOS we edited before are RSA Signed internally, that's why each test you did was a brick. Send me link to stock download of this BIOS you think might not be encrypted, I can't check that via dump.

F12 BIOS sounds pretty new, probably same as the other we were editing. You need to check out early BIOS like F3-F6 etc, if the names are like that, I'm sure you get what I mean

ah yes you are right I mean that the stock bios IS encrypted. and you don;t see anything with andy's tool at the read out bios

f12 is the oldest, https://ftp.hp.com/pub/softpaq/sp55001-55500/sp55375.exe

here are some success https://www.bios-mods.com/forum/Thread-H...SN-T-CMOS-RESET diffrent sp name that is for sure
board id is 17FC ( accoording the wndows flash)