macbook a1707 15 inch trackpad dead. blown fuse identification

[dellxps15]

hi all, got this macbook with dead trackpad. after some investigation i found that fuse is bwlown. it's marked with a K on it. anyone kjnow it's value ? it is a 0402 package.

another problem is: i tried another trackpad that was working fine, but the feedback sensor was not. all volts are present, but the click mechanism isnt .

[mon2]

It is a trackpad so should not be very high in current. Consider a 500mA - 1A tops SMD fuse here. If in a pinch, place a 0 ohm resistor here. The 0 ohm resistor will act like a wimpy fuse if it is ever shorted. You can review the datasheets for 0 ohm resistors @ 0402 SMD size to note the peak current that is permitted.

[dellxps15]

tnx for the reply mon, googling fuse marking code ive seen that X marker is used for 250mah, but on mouser i cant find any of these fuses with a X marker on them. the line is a 3,3 volt, so any other fuse i have is too big (backlight; ppbus and so on). there is no short there , so ill put a 0 omh resistor and see what happen.

any suggestion for the no feedback ? (magic trackpad haptic should be the function not working here).

edit: maybe i can use a 0,002mm wire

[mon2]

No direct experience with the haptic feedback on the trackpad which has been a guarded secret. I briefly recall them using the cypress microcontroller onboard but only invested a few minutes on the review.

Any fuse of this current rating will work. You are well under the peak voltage so it is safe. Can be really any brand but some offshore vendors use cheaper quality fuse wires so their fuses do not trip as fast or not at the expected threshold of current. We caught one such vendor we met in Hong Kong and proved our case. They had to rebuild the 5k++ fuses we had to order for their moq. This time they used some better wire from the UK or Germany.

The haptic issue is likely buried inside the trackpad.

[dellxps15]

update: i got a new trackpad from amazon, but the seller send me a used one.... i tried it and trackpad was working but no feedback on click, so i take the original old one with blown fuse (not 100% blown.... in diode mode was reading 1600 (yes a bit too hight for a fuse) and after soldering a wire of 0,002mm all is back in working condition and also the click feedback is back to normal status.

tnx mon2 for the help.

for the fuse, for a 250mah i need to order from china with ofcourse candbe sure of their uality and also would take like 20 days to come and customer is in hurry.

i think ill give it back to customer with the wire soldered in it, and if something roke ill replace the wire with a good fuse ( ill order good fuse from mouser in the next order i have to do)

[mon2]

Great Better and more reliable to order the fuses from Mouser / Digikey / Arrow, if available. A small deviation of the fuse rating will not be harmful if another one is available. In the end, it is about how well the owner is behaved. One bad liquid spill will take out the trackpad.

[Aliencomputres]

Put a 0 ohm resistor .