That should be ok then.
*Most* inbuilt laptop serial ports worked reasonably well, although sometimes at a lower-than-spec voltage. but the serial chip in the megajolt isnt fussy about voltage from my experience. even 5v workks ok.
A good test that your pc's serial port is working is to link pins 2 and 3 on the computer side, fire up hyperterminal (assuming you're using windows, accessories). set for "direct to com<x> (whatever your port is) at 19,200 or 38,400 bps with echo off, and type.
If your port is working, the pin 2-3 link should loop your typed characters back from Transmit (tx) to the Receive (rx) and make them visible as you type them. If its not (and echo is off), then what you type wont show, meaning you need to find out if your serial port is enabled, configured etc correctly.
Make sure you have the right version of the configurator software to match your Megajolt - for a V3 jolt, you want the one from this page..
http://autosportlabs.net/MJLJ_V3_Downloads
next, If its an inherited Megajolt, rather than a new or freshly built one, either tell us what area you are from and perhaps find an experienced megajolt user who can test your 'jolt with a known working computer/serial combo they use..
If thats not practical and you're sure your computer/serial/software/cable is OK, then its time to delve in with a multimeter and start checking some voltages and stuff to see if the serial chip in the 'jolt is OK.. are you comfortable driving a multimeter or will you need a techie for that ?
