Advanced Detection Systems 1200E Series Installation Manual And Owner's Manual page 31

PROCEDURE FOR BALANCING A MODEL 1200 SEARCH HEAD
(Refer to the circuit board drawing and front panel layout drawing)
Observe the five red "calibration" LED's on the detector's front panel. Normally, the LED on the left,
and maybe the second LED, will be lit to full brightness and the center LED may or may not be lit, but should
be at some brightness level less than full. The two LED's on the right will be unlit. If the center LED becomes
bright or if either of the two LED's on the right becomes lit, the metal detector should be rebalanced. When the
metal detector is first turned on, it will cycle through a "self test & calibration sequence". During this time there
will be a "residual" value displayed on the screen. As the detector becomes more balanced, this number will
begin to decrease. Make note of the lowest number seen on the screen before the detector moves on to the next
display. If this number is above 500, then the unit should be rebalanced. The procedure is as follows:
Refer to the front panel layout and the circuit board drawing attached.
1. Remove screws from main door assembly. The keypad is attached to the detector by means of a ribbon
cable. Remove the door carefully to protect the ribbon cable.
2. Remove the six screws from the front panel of the circuit board. The front panel is attached to the circuit
board with two ribbon cables. Lean the front panel forward, being careful not to unplug either of the
ribbon cables. CAUTION: There is live power on the terminal strip at the bottom of the circuit board.
Make sure that nothing, including the front panel, comes into contact with the terminal strip.
3. On the circuit board layout drawing attached, locate jumper J6 and the Reset button SW1
(approximately in the center of the circuit board). In normal operation the J6 jumper is not jumpered
across its pins.
4. Place the metal detector in "maintenance mode" by placing the J6 jumper across the two horizontal pins.
Press and release the reset switch SW1. The onboard computer has now been restarted in the
maintenance mode.
A flow chart of the maintenance menu is attached. The remainder of this procedure will be explained using
menu numbers and will assume that you are familiar with moving from screen to screen using the * key to
scroll and the # key to enter.
5. Navigate through the menus to screen #12 and set the calibrate pot to 50. This is VERY important!!
Even if the screen says that the current setting is 50, you should enter 50 as the new setting and press
enter. Scroll through to find an exit and return to screen #3.
Please read the entire instruction sheet before beginning.