I need how to open this Dell service menu option in dell latitude e6420

[sohail5307]

I need to open service menu of Dell laptops like image in attachment
Ignore my English

I want beacause i flashed mec5055 using rt809h now it's does not have service tag, but when I install service using F2 in bios setup after save service tag and press disable manufacturing mode using alt+f then battery chagring is permanently disabled. I want to resolve this problem

[tomodachi]

Re: I need how to open this Dell service menu option in dell latitude e6420

Same need here,how do we access to manufacturing mode ?

[khaahk]

Re: I need how to open this Dell service menu option in dell latitude e6420

Battery id is entered into boot block of the MEC and this is known only to Dell. Battery charging will be disabled in normal mode. For now only possibility is to use MEC from donor board. The boot block is protected from read, so you can not use working MEC to copy it.

[sohail5307]

Re: I need how to open this Dell service menu option in dell latitude e6420

Battery id is entered into boot block of the MEC and this is known only to Dell. Battery charging will be disabled in normal mode. For now only possibility is to use MEC from donor board. The boot block is protected from read, so you can not use working MEC to copy it.

Now I think I found some new information
I think need to gnd fwp# for unlock boot info of mec sio
Checkout pdf from attachment

[khaahk]

Re: I need how to open this Dell service menu option in dell latitude e6420

If the internal register of MEC has BOOT_PROTECT_EN set then reads will be disabled. I think that fwp pin is an external way of protecting writes to MEC. Check MEC1632 datasheet for reference.

Now I think I found some new information
I think need to gnd fwp# for unlock boot info of mec sio
Checkout pdf from attachment