The pictures show the layout as of 4 September, 2004.

On this page:
Adjust the "Seconds" counter
"Tuning" the sensors:
"Top Coin" sensor,
"Bottom Coin" sensor,
"Finish" sensor,
"Home" sensor,
The Axle and centering spring.
Changing Fluorescent tubes and starters. Power supplys.

Adjust the "seconds" counter

You will rarely, if ever, have to adjust this pot (potentiometer). Refer to the Top Circuits picture.
To adjust the "seconds" counter, remove the top wooden cover.
The new light switch adjustment pots are connected to the cover so the cover is attached to the light switch circuits. The wires are about 200mm long. Try not to jerk them.
While holding the pulse generator circuit board, carefully turn the black trim pot with a small screwdriver. A small adjustment will make quite a large difference.
Ensure that no wires get caught when replacing the cover. Go carefully and you'll be fine.

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ADJUST THE SENSORS IN THIS ORDER:

STEP 1- "Top Coin" sensor

As the LED - refer to the Top Sensors picture - is very close to the sensor there should be a fair margin in the adjustment and therefore this sensor should not have to be adjusted often.
It is no longer necessary to remove the wooden cover and fiddle about with a tiny screwdriver to adjust the sensitivity of the 3 sensors at the top of the game. Ordinary pots (without knobs to leave them less obvious to the public) poke through the rear of the top circuit box and can be adjusted with fingers. They are labeled on the top of the wooden cover.
1a Check that the "TopCoin" LED is lit.
1b Cut a strip of light cardboard about 20mm wide by about 250mm long (card or thin plastic is preferable to metal which might damage either sensor or LED) and insert it into the coin slot. If the relay clicks, this switch does not need attention.
1c Remove the card. Check that you are about to adjust the "Top Coin" pot and slowly turn the pot until you hear the relay click. If you reach the end of travel with no result, slowly go back the other way. When it clicks, go just a little further in the same direction.
1d Insert the strip of card down the coin slot.
If the relay clicks, insert and remove the card a couple of times, if necessary making tiny adjustments to the pot.
If you insert the card and the relay doesn't click immediately, slowly rotate the pot (back the way you came from, I think!) until the relay clicks. Remove the card and a tiny adjustment should get a click. Insert and remove the card, adjusting if necessary.

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STEP 2- "Bottom Coin" Sensor

As for the "Top Coin" setup, the LED - refer to Bottom Circuits & Coin Slot picture - is very close to the sensor and should not have to be adjusted often.
Rather than removing the acrylic face and the light box covers and then flipping the box over to gain access to the circuits, I recommend removing the cash box and the lower front MDF panel and lying on your back with your head where the cash drawer would be. Not dignified or comfortable, I grant you, but far easier. Just above and to the right you will see the "Bottom Coin" light switch circuit. Use a small screwdriver to gently adjust the trim-pot.
The procedure is virtually identical to the "Top Coin" setup.
2a Check that the "Bottom Coin" LED is lit.
2b Insert a strip of card up the bottom coin slot. If you hear the relay click, this switch is ok.
2c Remove the card and slowly turn the pot until you hear the relay click.
2d Insert the strip of card up the coin slot.
If the relay clicks, insert and remove the card a couple of times, if necessary making tiny adjustments.
If the relay doesn't click, make a tiny adjustment. Remove and insert the card, adjusting if necessary.

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STEP 3- Adjust the "Finish" sensor

Rotate the wheel so the end of the maze lines up with the bottom coin slot.
Look at the reflective tape on the front rim of the wheel near the finish LED and sensor - refer to Top Sensors picture. When the wheel is moved back and forth the light should bounce off the tape into the sensor. Unless the sensor or LED is obviously out of alignment do not move the LED or sensor at this time.
3a Check that the LED is working.
3b Rotate the wheel to the finish zone and listen for the relay click as the tape passes the LED and sensor. If it clicks, all is well.
3c Check you are about to adjust the "Finish" pot at the rear of the top wooden box and with the wheel rotated so the tape is under the LED and sensor slowly rotate the pot until the relay clicks.
3d Rotate the wheel so the tape moves out of the LED/sensor zone and adjust the pot, repeating until satisfied.

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STEP 4- the "Home" sensor

The easiest one to adjust!
The wheel should have returned to the Home position, more or less. The small green LED - refer to Top Sensors picture - should be lit or should light if the wheel is rotated slightly.
If it doesn't, use the procedure for the STEP 4, "Finish" sensor.
4a Check that the "Home" LED is working.
4b Check that you are about to adjust the correct pot.
4c Listen for the relay clicks as you adjust - if you hear a clicks but the LED doesn't work it may be a bad connection or blown LED.

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Axle and spring

The wheel centres itself in the Home position by means of a spring - see Spring picture - which tensions a wire rope which passes through the axle - see Axle picture.
The spring needs to be under some tension all the time to ensure the wheel returns Home, and because the spring is a compression type, the user gets a gradual end to the wheel's rotation rather than a sudden stop.
The wire rope will need replacing occasionally. The wire rope passes through the axle and is locked in position by the spiral clamp.
We have used 3mm galvanised multi-strand wire rope (the more strands the more flexible, and galvanised is more flexible and less brittle than stainless steel) and the hole through the axle is countersunk and smoothed. Even so, the bending and unbending will inevitably cause a break.
a Easiest acces is through the rear of the donation box. Loosen the wiring and unscrew and remove the MDF panel.
b Loosen the spiral clamp and the wire rope grips and remove the old wire.
c Adjust the turnbackle to its longest setting - remember to loosen the lock nuts and that one thread is right hand and the other left hand. ;-)
d Insert the new rope, tighten everything up and set a small tension on the spring.

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Changing the Fluorescent tubes

a POWER OFF! Easiest from behind. Loosen the wires and remove the MDF panel.
b Loosen the top panel at the rear of the box. Lift it carefully as the tubes are attached.
c The lower tube fitting can be detached by holding the tube in one hand and twisting the fitting about a quarter turn in either direction. The fitting can then be slid off the tube.

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Power supplies and ballasts

The junction box contains 240v connections.
TURN POWER OFF BEFORE PROCEDING
Remove the lower front MDF panel and the transformers and ballasts are located on the right.
All components are fairly commonplace: the transformer for the chases is a wire wrapped type and is identical to those used for halogen lights all over the country; the j-box has a 170° cutout switch inside; the ballasts are standard; the DC power supply should be easily available at electrical and hardware stores.