The driver board houses the lamp drive SCRs, the solenoid drive transistors, and a sound circuit capable of making four "beep" type noises. It takes a data signal from the CPU board via a short ribbon cable, and has connectors for the controlled lamps, solenoids, and speaker (not used on games with dedicated sound boards).
The lamps are controlled by the SCRs (SCR1 ... SCR52, and SCR53 ... SCR64) on the left hand side of the board, via support logic chips at IC1 ... IC8. Lamp voltage (5.6VAC) leaves the Power Supply board on connectors CN3 (Playfield), and CN4 (Cabinet/Head), goes through the wiring harness, returns on Driver Board connectors CN16 ... CN20, and is grounded through the SCRs.
There are two sets of SCRs used for the lamps. The first set (SCR1 ... SCR52) are rated at 0.8A and listed on the schematic as 2N5060 parts, labled as "Single Lamps". The other set (SCR53 ... SCR64) are BAX62 parts, rated for 4A and labled as "Group Lamps". I have not found a source for BAX62 SCRs, but they can be replaced with C106B1 SCRs, which are available from Jameco as part number 14736. According to the catalog page, these are equivilent to NTE5455 or 2N6238 SCRs. I have seen several driver boards with various SCRs here, so it appears that any SCR with a sufficient rating should work fine..
The 2n5060 are used to drive individual bulbs, and the BAX62 are used to drive multiple simultaneous bulbs.
The solenoids are driven by transistors (Q1 ... Q21) on the bottom right quadrant of the board, via the support logic chips at IC9 ... IC11. As with Williams, Bally, etc., Zaccaria coils are always hot, and the ground side is switched on or off by the driver transistor to turn on (off) the solenoid coil. Most of the solenoid ground return lines are on CN14, but some appear to have been intended to double as lamp or other feature drivers via CN13, CN15, CN16, and CN20. 39VDC is supplied to the solenoids via CN3 on the Power Supply board.
The schematic and parts lists call for BD649 transistors for the solenoid drivers. TIP102 transistor are a close match and are rated higher than the BD649, so it should be safe to use TIP102s to replace these.
For the games that used it, (Winter Sports, Future World, and House of Diamonds) there is a simple oscilator circuit capable of producing four tones controlled by IC9. This is composed if IC15, IC16 and IC17, with capacitors C27...C30, and resistors R83...R86. There is a volume adjustment pot on the board, designated as P1. The output of this goes to the speaker mounted on the backbox door, behind the backglass, via CN13 on pins 1 and 2.
For the games that use the sound section of the driver board, R83-R86 and C27-C30 are varied to produce different sounds.
|Resistor / Capacitor||House of Diamonds||Winter Sports||Earth Wind Fire|
|R83/ C27||47K / 10nF||15K / 10nF||22K / 10nF|
|R84/ C28||39K / 10nF||47K / 10nF||68K / 10nF|
|R85/ C29||56K / 10nF||100K / 22nF||100K / 22nF|
|R86/ C30||68K / 10nF||220K / 22nF||220K / 22nF|
On the 1B1111/0 board transistor Q1 is shown having outputs on CN20 pin 18 and CN18 pin 15. However, on the earlier 1B1111 board Q1 is only connected to CN20 pin 18, and CN18 pin 15 is actually connected to SCR17 and CN20 pin 6.
The schematics for Winter Sports show the 1B1111 arrangement, and the manuals for Shooting the Rapids, House of Diamonds, and Future World also seem to confirm this via the connector chart. It appears that the 1B1111/0 was used on the remaining six 1st Generation games.
|Winter Sports||1B1111||No wire / connector chart included.||Confirmed|
|Future World||1B1111||CN18 pin 15 not connected||Unknown|
|Shooting The Rapids||1B1111||CN18 pin 15 not connected||Unknown|
|House Of Diamonds||1B1111||CN18 pin 15 not connected||Unknown|
|Earth Wind Fire||1B1111/0||CN18 pin 15 not connected||Confirmed|
|Hot Wheels||1B1111/0||CN18 pin 15 not connected||Unknown|
The most common failures on Driver boards is solenoid drive transistors. A shorted coil or a shorted diode on a coil will instantly destroy the associated transistor when the coil is fired. The fuse for the 39v supply will also blow, but rarely quickly enough to save the transistor. If you have a board with failed transistors on it, especially if the case is blown apart, that is a big clue that you probably also have a shorted coil or a bad diode. Check them before reconnecting the board to the game, or you will have to replace the transistor again.
Since all of the lamps are directly controlled, a single non-working lamp (assuming that the bulb and socket are good) is likely to be a failed SCR. The SCRs can also, rarely, short out and the lamp will be constantly on. More than one or two non-working lamps may be a clue that the decoder IC (IC1...IC8) may have failed.
Some of the published schematics for the 1B1111 driver board have an error showing the input signals S21, S22, S23, and S24. These signals are on pins 8, 7, 6, and 5 of ribbon cable connector CN21. The erroneous schematics show them on pins 21, 22, 23, and 24 (of a 20-pin connector!). The schematics for Future World, Winter Sports, and Hot Wheels are correct. The schematics for Fire Mountain, Space Shuttle, and Locomotion have the error. Currently, Earth Wind Fire, Star God, Shooting the Rapids, and House of Diamonds are unknown, as I do not have copies of these to check.
David Gersic [an error occurred while processing this directive]
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