Diagnosing short to ground issue

[Leefreeman97]

Hello, I have a pcb from an e scooter which had a faulty diode but even after removing it from circuit, it still has a short to ground on the three components circled. I have removed every cap on the board and tested one by one and the short is still there and all the caps test ok. Could this be because I haven’t put a diode back on it yet or where do I go next please?

 

[Delta Prime]

Hello, welcome to electronics lab.
I see coax connector gigahertz .What part of your E scooter is the circuit from?
If it is a diode the PN Junction can fail, open or short circuit. You measured voltage conduction in forward & reverse bias. If it was a reverse voltage or current protection diode.
then you did not reinstall the protection circuit needed.
If it was a voltage steering diode then that circuit would no longer conduct because you did not install it you might have gotten lucky…
install the diode and apply power.
But if you’d like, you could disclose make, model, year, battery voltage, of your scooter please…

 

[Leefreeman97]

The diode is a bio directional diode and the make of the scooter is a flykul quite an old e scooter the battery voltage is 36v and the pcb is from the stem of the scooter, it connects the power button and brake to the main board.

 

[Leefreeman97]

Could it be that I need to install a new diode and then the short to ground will go?

 

[Delta Prime]

Thank you for the information; if it is a TVS diode it is likely used for electrostatic discharge protection, from high reverse voltage pulses.
This is all speculation on my part. I’ll see what I can dig up for you. I need a schematic.

 

[Leefreeman97]

That’s correct, I’ve been told it’s a tvs diode as the replacement I was recommended is too. Would this not being in circuit cause the short to ground?

 

[Leefreeman97]

Where do I put the red and black wires to inject wires to inject voltage please?

 

[Leefreeman97]

Also, when measuring both pads when they beep both sides this is the readings I get in the picture.

 

[Delta Prime]

I see solder balls, solder, splatter, short circuit components thank you for the high deaf photo I can no longer help you.