what went wrong

[upup]

My com port was connected via rs232 to a radio. Laptop were switch off, ac were connected. Point 5, signal groung became very hot and laptop refusd to charge or ztart. The ac supply the radio with 12volt. I think the sig gnd were high from somewhere. The data did work before the fun.

 

[undesign]

My com port was connected via rs232 to a radio. Laptop were switch off, ac were connected. Point 5, signal groung became very hot and laptop refusd to charge or ztart. The ac supply the radio with 12volt. I think the sig gnd were high from somewhere. The data did work before the fun.

:wtf:

Are you drunk Van Vuuren?

 

[guest2013-1]

Who the hell still has a laptop with com ports, nevermind Rs232 on it?!

THAT is what went wrong

 

[UnUnOctium]

too much return current. Something somewhere shorted your 5/12 V and GND

 

[upup]

We have a lot of stuff working on the comport.
This laptops were very expensive with this comport. a USB to serial does not work on all our systems. And still running virtual pc with win 98 to talk to some stuff.

Most of our stuff got a comport to set the IP, then we can lan it.

 

[sajunky]

I think one ot the power supply has a leak to the mains. It is only explanation that current loop is closing through the ground of the RS232 pin.

Both power supply units must be checked for a leak, it could be intermittent -- self healing. For safety reason, but also there is possibility destroying inter-connected equipment.