Problem- Potential Short

[dsnellen]

I received a new P-C 690LR router. When trying to do a tool zero, the normal put clip on bit and touch pad routine wasn't working. I tested the circuit by touching the clip to the pad and the circuit worked fine. As I continued to play with it, I noticed that touching the clip to the bit was causing sparks! Never had that happen before. The clip is connected to 5V and the zero pad is connected to pin #11 (C10). What would be causing the sparks? The probe works flawlessly with other routers. The computer, electronics and router have a common ground.

Thanks

Dave

[dsnellen]

Hey guys, I could use some assistance here. I used the voltmeter to do some testing.

1. There is a 6vDC charge on the bit & router body. From pin #11 (C10) to the bit when the router is plugged in (but naturally turned off). It's the same whether plugged into the Relay Board or directly to a wall socket.

2. The voltmeter also shows a small AC voltage (confusing the DC flow?) Or maybe the voltmeter is showing the AC flow as DC voltage.

3. This is puzzling as the Relay Board is switching the black wire so logically there is not an AC circuit unless somehow there is a current flow between the common and ground wires.

4. I have a solid ground among all the parts. The Ohm meter show 0 between the router body/bit and the table. The ground between the router and table also exists when the router is plugged into the wall socket. I think I have achieved what Al calls a "ground star".

I'm thinking the sparks are caused by the DC C10 circuits coming in contact with a small AC charge. Although the router will start and run, I am thinking it may have an internal short/electrical issue somewhere and that I should return it. Anyone have any thoughts?

Thanks for your ideas.

Dave