BRINK electronics has released a replacement for the CA3081 transistor array used on many pinball machines from several manufacturers. CA3081s are not yet completely unavailable, but they are long obsolete and the supplies of them are drying up, so it is only a matter of time before products like this are the only way to repair games that use these chips.
The top side of this board features seven BC548 transistors, some traces, and a silkscreen. The bottom side of the board features header pins soldered to a 16-pin socket. The socket raises the board up off of the circuit board it is installed on, which should provide sufficient clearance so that it does not interfere with any surrounding parts. Since this board is physically larger than the CA3081 that it replaces, clearance on the sides could be a concern if more than one of these was to be installed close together. Fortunately, this shouldn't be necessary, or a problem.
I installed this board in place of a CA3081 at IC38 on a Zaccaria 1B1165/1 (2nd generation) CPU. IC38 is part of the switch matrix on these games, and is commonly damaged by somebody accidently short circuiting the +39V solenoid voltage in to the low voltage switch matrix. IC38 takes the brunt of this and dies, rendering the game inoperable. I first confirmed basic operation of the board on my test bench, where it worked fine. I then installed the board in one of my games (Farfalla), and confirmed that it worked fine there as well.
My only complaint with this board's design is not the board itself, but the silkscreen on the top side. The layout of the text superimposed on the chip outline puts the "0" right in the chip notch. This is combined with a stray "c" on the other end of the chip silkscreen, which makes it non-obvious at first glance where pin 1 is located. Closer inspection makes it clear, of course, but I would like to see the silkscreen modified to make this less confusing. BRINK electronics says that they will be updating the silkscreen to address this, so hopefully it will not be a problem for anybody using these boards.
David Gersic [an error occurred while processing this directive]
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