KV 2 won't power on

[tonyhotwheeler]

bought a new Soviet KV 2 worked fine a few days then went to turn on no light flash appeared has there been any problems with the 7.0 receiver boards

[ccarley]

The KV-1 I received for Christmas has a similar issue, but it's not the 7.0 board in my case; the actual on/off switch is either oxidized internally or has some other intermittent connection issue. Wiggling mine between on and off enables it to function and it's getting better with time, leading me to believe it might just be oxidized internally.

The on/off switch can be tested pretty easily if you take the upper hull off; short the 2 leads to that switch (simulating on) the tank should come to life, given the battery is good...

Clay

[tank_me]

If it's using a Tamiya style connector, it could be that also. They aren't very reliable.

[tonyhotwheeler]

I checked voltage at the batt connector connection going into the receiver then at the switch and the connection where it plugs into the receiver all have batt voltage

[Zippersnapper]

I checked voltage at the batt connector connection going into the receiver then at the switch and the connection where it plugs into the receiver all have batt voltage

Tony, looking at your original post you say there is no flashing light . I think were assuming that the tank in general is not operational rather than a possible headlight LED burned out or pulled loose from the Board. I see you have checked all the connections going to the Board presumably with a multimeter. Below is the voltage output for all ports. I have found that having a JST and Dupont plug with bare wire makes it easy to plug into any given port and test its output. I would advise checking the outputs to see if your getting anyting. The main switch -CN1 would be the first place to check by doing a continuity check. This of course will only tell you if the switch itself is bad (or by doing the same thing on the switch). If you plug in a jumper JST on port CN1, then the board should come to life the second you plug the battery in. If it doesnt, or your not getting any voltage from any of the ports, then that 7.0 Board is DOA.





Let us know your findings

[tonyhotwheeler]

update on my kv2 finally got a replacement 7.0 receiver box installed found the wire for the led and machine gun plugged up incorrect must have shorted out the board works ok now thanks for all the useful info

[tank_me]

An electrical short, or short circuit, is a low-resistance connection between two conductors (objects that allow electricity to flow through them) that are supplying electricity to a circuit. A short occurs when a current follows an unintended path, bypassing the route it’s supposed to take.

An LED with reverse polarity will just not work. That wouldn't short out the board. An LED is a diode and diodes only allow current in one direction. If it's reversed, it doesn't pass any current as in it's an "open" or infinite resistance on a multimeter. Infinite resistance doesn't pass current. If the LED was plugged into the wrong port, with the wrong polarity once again no current will pass and no short. If the LED was plugged into the wrong port with the correct polarity it would more than likely just blow the LED by providing too much voltage to it. They make a nice popping sound when they blow and the smell pretty bad. :) Typically LEDs are pretty forgiving and usually don't blow instantly unless severely overvolted.

Derek

[Zippersnapper]

Yea, I would like to take a look at that DOA 7.0 myself.