Can one flash custom modded bios via bios flashback on z170 chipset?

Not sure if it still works via bios flashback on asus motherboards since I remember one reddit guy mentioning it doesn’t work anymore cause of some “checks” can someone confirm this for me?

Yes, edit file as-is in a capsule and then flash back, or extract body of capsule with UEFITool (so actual BIOS) and then edit, then put back into capsule via hex
Then rename encapsulated file to the proper flashback required name.

Is there a full on guide for this? and would this work for enabling coffeetime mod for asus maximus viii ranger

Guide for what? Do you mean putting a modified BIOS body back into a capsule via hex? If yes, no, there’s no guide that I know of.
Open BIOS in UEFITool and see how large the capsule is, check body of capsule (actual BIOS) and see where it starts/it’s offset. and then open capsule BIOS in hex and mod BIOS body in rom and copy mod BIOS entire file and past at the capsule file where the BIOS begins.
If you can’t figure that out, tell me your motherboard model and I will tell you more exact details on how to do that, sometimes the capsule is 2KB and sometimes 4KB, so I can’t explain exactly without checking your BIOS.

For coffeetime mod or similar you have to write to the ME and FD region of the BIOS, so you need flash programmer (CH341A) not flashback.
You may get lucky and Flashback will write in the ME version you put in your mod BIOS, but not often does this happen. FD region will never be written with flashback, this is why it’s required to use a flash programmer.
And, .CAP or encapsulated files (even if named bin or rom) cannot be used with programmer, so you will have to open the BIOS file in UEFITool and if you see AMI Caspule, right click, choose extract body and that is what you use with programmer.

Motherboard is an Asus Maximus VIII Ranger

That BIOS has 2KB capsule. So open stock .cap BIOS in hex editor and open copy of your mod BIOS in hex editor. Select all your mod BIOS, then copy. Then go to stock.CAP BIOS and go to location 800h, and paste the mod BIOS, then save as M8R.CAP and you are done

hm is there any specific reason to need to write to ME for the coffeetime mod? does it need a specific version orrr

Yes, ME FW needs to be a specific version, often one lower than your current but not always so check current and you may be OK. If you used the AIO mod tools this will already be using correct latest version for the mod to work, 11.6.xx or 11.7.0.1229 is latest ones you can use

Checked intel ME version and it’s on 11.6.xx
How do I backup my whole bios image and can I just go and flash modded 2202 bios with coffeelake cpu microcode via flashback as intel ME is good to go?

Great, 11.6 is good, just make sure you don’t use any BIOS as a source for any flash method, that contains a ME FW above the 11.7 one I mentioned (in case ME FW gets updated in the process).

To make a complete backup, you can try AFU, however if often will only dump BIOS region, you can try universal BIOS backup toolkit (google it)
Other than that, you can also check BIOS exit page and see if you have a save BIOS function, or if manufacturer has a “In Windows” BIOS update tool, those often have backup option too.
Aside from those things, you only have option to first do pinmod to unlock FD, then you can dump entire BIOS via FPT, or use a hardware flash programmer such as CH341A

Yes, you should be able to flash your mod BIOS now if you want. I’d backup BIOS region via FPT or AFU first, just to have a copy. Mod still may not work, since you cannot write in the change at FD region that’s required for this type of BIOS mod.

hmm what is this pinmod?

also is there any info on some other pins on my motherboard