Here is an extract from an E-Mail sent to another CompShop customer who was having similar problems.
"There have been two versions of P94 in the recent past. The type which provides power to the receiver from the main motor batteries (via a Battery Eliminator Circuit, or BEC) has a voltage regulator fitted. This is a small additional circuit board which is mounted on four gold pins above the main board, just between the two black relays and the 14-pin microprocessor chip. The other type doesn't have this board and requires the power for the receiver to be supplied from a separate power source e.g. a battery pack or a P92/P107 distribution board. The voltage regulator circuit on the BEC version of P94 has proven to be unreliable so this may be the source of the problem. This type has been withdrawn pending CompShop finding a better regulator".
If you have a BEC version then it would perhaps be best to return it to Component Shop and ask for a replacement. If your P94 is one without the voltage regulator then make sure you have NOT disconnected any wires from its plugs. As I said earlier, P94's relays should click several times when you power up the system, then the unit should operate properly. If they don't then either there is no power connection from P94 to the receiver or the unit is faulty.
Dave M