Question Laptop won't boot if onboard screen is detached

dnaeeeutd

Prominent
Dec 17, 2017
5
0
510
Hi everyone,

I have bought my laptop 7 years ago and it is still working perfectly until now. It is a Dell Inspiron 7520 non-SE with Service Tag 1VJBFV1.

Onboard screen panel seems to be old enough that some weird red areas show up on this screen (more noticeable when I open darker photo).

Therefore, I decide to disassembly my laptop and redesign it as a portable computer case.

However, if I detach/remove its onboard screen, the laptop won't boot anymore, if I reattach the screen, everything will work fine again.

It seems like during booting process, the laptop itself will check for the presence of peripheral devices and if something is missing, the process is halted.

The funny thing is I have other 2 laptops (1 Dell, 1 Sony) serving the same purpose and they can boot fine no matter there is an onboard screen or not.

Is there anything I can do to fix this problem?

Thank you.
 

dnaeeeutd

Prominent
Dec 17, 2017
5
0
510
Mind sharing the make and models of the other laptops that have undergone the same work of being a replacement desktop? Some makes/models of laptops will not boot when the display cable is disconnected as a security measure.
Well the Dell one is Dell Inspiron 14Z 5423, its CPU is Core i3-3227U same design as my 7520, just smaller. The Sony one I don't remember exactly, it's cover is matte black finished plastic, it has a 15.6" touchscreen , NFC and the CPU is Core i3-3217U
 

dnaeeeutd

Prominent
Dec 17, 2017
5
0
510
Since I can't find any LVDS to VGA converter, I'm thinking of tricking the system. Specifically I will cut the LVDS cable, plug into motherboard, use multimeter to measure voltage at output, then I can use a very low resistance value resistor to be a load, let the system think that onboard screen is already attached and is ready to boot up.