What's new

Type cover pinout and +Ve voltage


New Member
Hi there!

I must have bought one the worst surface pro 4 produced by BSOD Micro$oft: It has both the screen issue and the type cover issue...
Well, I have solved the flashing screen by replacing it with a sp5 screen. Hope it will be a durable fix.

However, for the type cover issue, I have not been able to find any solution on the net. Sincce I ruled out the software issue theory (the type cover, a new one, is not recognized in UEFI mode), I started digging further. I measured the voltage between the +Ve pin (the one on the far right) and the others and found something between 2.7 V and 2.9 V only. Of course Microsoft could easily put a stupidly odd voltage, just to make sure nobody can jailbreak the type cover port, but I was still expecting a more conventional voltage of 3.3 V or 5 V.

Since I only have one computer, can't compare my result to a working one. Could someone measure on his (working or not) computer the voltage between +Ve pin and the others and report here please? My guess is that the excess of heat generated by the tablet, which sometimes leads to screen failure (flashing issue), it might also be the case with the type cover's ribbon/connexion to the motherboard.

Thanks and cheers!


Staff member
You have amazing patience, there, @TSR

I can’t help you since I have the SB2. If you post a pic of the +Ve pin location, it might prompt someone else to help you out.


New Member
I believe that the +Ve pin is pin 8 (screen is facing upward here).

Type Cover Port.jpg

Here you can find what I have measured on my type cover port.

Voltages Type Cover Portt.JPG

I also measured the resistances between the pins. Resistances 6-5, 6-4, 6-3, 6-2, 6-1, 2-1 and 9-10 vary, depending on whether we put COM on pin 6 or the other pin (must be because of diodes).

Resistances Type Cover Port.JPG


New Member
Hello TSR,
I have the sames pb than you.
I have had flickering gate that i have solved by replacing the screen with a SP5 screen (worked pretty well), and i have now cover type issue since couple of month.

I have tried everything without any success, but really everything, even reinstall windows image. I have 3 cover types, none of them is working.

I have also measured with ohmmeter each pin, and I have found 3,3V and 5V. I could tell you which pins regarding your schematic. I m pretty sure that the voltage is correct and as I don t understand why the cover type do not even light.
I currently use a cheap bluetooth cover type and it s so boring.