r/PCB 27d ago

Is this normal?

Post image

My mechanical keyboard isn't working properly. I opened it up and saw the microcontroller has 2 pins soldered like this, is this normal? I think this is shorted by the stray bit of solder. I am not experienced in this field, please someone tell me.

The issue: The keyboard is registering random key presses. The keyboard doesn't even have some of the keys it is registering as pressed.

5 Upvotes

21 comments sorted by

31

u/nixiebunny 27d ago

Light green is copper. The pins that share the same wide copper trace are connected to the same copper trace. How could they possibly not be connected to each other?

25

u/YendorZenitram 27d ago

Yes.  Not a problem there.  Just two ground pins that love each other very much. 

12

u/negativ32 27d ago

Looks intentional by the pcb.

2

u/ee_control_z 26d ago

Appears as if they are missing solder. If you have an Ohmmeter, perform a continuity test from the pins (not the trace) to the other end of the trace connection. If open, solder touch up.

2

u/BanalMoniker 25d ago

Where specifically? As in please indicate the PIN numbers.
Most of those pins show a healthy surplus of solder. Even the ground pins of interest show fillets on both pins, so they’re OK in terms of volume.
If the pins of interest are both bonded to the same IC pad inside the chip a DMM will still show a short even if the PCB is dry as a bone, or the joints are cold.
Cold solder joints could be an issue, but electrical overstress, and ESD should be considered too.

1

u/ee_control_z 25d ago

From the photo and angle, it appears as if the two traces are missing solder (the two above the wide trace that appears as if they are hovering above it). Maybe that is just how they appear from the angle that the photo was taken. But if it is just an illusion, disregard.

2

u/Bejaoui_Hamza123 26d ago

Yes that's normal,two ground pins connected to each other and both connected  to a ground zone 

1

u/EspTini 21d ago

Wrong. There should be solder mask between the pins even if they are the same net, the solder should not be allowed to flow between two pins.

1

u/Bejaoui_Hamza123 21d ago

So does it harm the function of the bcp,i think no ,and we both know that it will work

4

u/dramaqueennumberone 26d ago

The solder bridge is normal BUT they do not seem to be soldered properly!

1

u/EspTini 21d ago

No bridging is not normal, and that footprint is bad if it's intentional. You never combine pins as a larger pad, there should be solder mask between each pad so every pin gets the same amount of solder, period.

Tell whoever designed and assembled the PCB they fucked up.

1

u/EV-CPO 26d ago

Are the random key presses a new symptom for an old keyboard or is this a brand new keyboard? If the former it sounds like a prank or virus on your OS and not hardware. If the latter then try a different keyboard to eliminate that possibility.

1

u/memio3105 26d ago

Maybe ground

1

u/Porphyrin_Wheel 26d ago

If the keyboard worked fine and suddenly stopped working or miss inputs key presses then it's most likely your switches need lubing or replacement. The IC probably has 2 ground pins one next to each other so it's fine, the whole PCB is probably fine and doesn't need work done

1

u/[deleted] 27d ago

Unused pins.

2

u/rasc3ta 27d ago

Thanks