hey guys i just pluged in my battery into my truggy and a cell in my nimh pack blew im wondering if my esc is ok any way tto check

Plug another battery into it

Cheers

Yep

Don't just keep plugging batteries into it. With high-power systems, that troubleshooting method can get dangerous and expensive.

There are perhaps a couple of methods that I might try:

1) If you have a multi meter, put it into resistance, continuity, or diode-check mode. Put the probes across the ESC power input leads, wait several seconds for the caps to charge, and you should see something other than a dead short. I just checked two ESCs in my living room (a brushed Losi and a brushless Novak Mongoose) with a cheap Greenlee meter, and both showed an open circuit after a second or so of applying the test leads.

2) You can hook up a current-limited power source and test the ESC function. A small bench top power supply is good for this, or you could use a 6V lantern battery, or put a 1ohm 10W power resistor between a good pack and ESC. The goal is simply to protect both the source and the ESC if a problem exists. Connect the "safe" supply, turn on the ESC, and wait a moment to see if arms properly. If it comes alive properly, then you can try to run an unloaded motor (remove the pinion).

If either of these seem intimidating, then you may want to return the ESC to the manufacturer for service. Good luck!

How is the battery connected to the ESC? Maybe it was connected with reverse polarity, that is red bat wire to balck ESC wire and viceversa ?

Other than that, do the ESC checks suggested above - and remember to disconnect the motor, before checking the ESC - the motor itself might also cause a short circuit.

The checks I recommended above can be performed with the motor connected, just so long as the ESC is properly recognizing the neutral position. If the presence or absence of a motor is affecting the results, then there is likely a problem with the ESC or a setup issue.