TECH: Firepower drop target retrofit


There has been a bit of traffic lately pertaining to the drop targets on Firepower, and it prompted me to put together this little info sheet.

I hope someone finds it interesting and/or useful.

Ted Estes
estes@mcs.com

Firepower Drop Target Retrofit

The original design for Firepower called for 2 banks of 3 drop targets instead of the 2 banks of standups in front of the flippers. The drop targets were removed at the last moment to save money and because the drop targets were sure to be a reliability problem in that location, since they would get heavy abuse.

If you look closely, you may find an early Firepower that had the wiring for the original drop target banks. Another clue to the early age of the game is presence of U-shaped cutouts behind the standup banks to accommodate "10-point" switches that become accessible after the drop targets are hit.

(I've been able to dig around in 8 or so Firepowers, and I've only seen one early one with the cutouts and wire harness for the drop targets. This doesn't count the actual Firepower prototype which I've had to pleasure to inspect.)

The software in the game works with either standup targets or drop targets. Here is the information on how to put drop targets into your Firepower.

(I've included wire color information here for completeness. You get bonus points if you use the correct colors for your conversion. The two games I've converted got their wires -- and drop target banks -- courtesy of a few old Disco Fever games.)

  1. Obtain two 3-bank drop targets. Any 3-bank sets from a Williams game made in the late 70's or early 80's will work (solid state game only -- no electromechs).

    Games made prior to Black Knight use a printed circuit board and horseshoe wiper switch. These are notoriously unreliable, but are the type originally used in Firepower. The horseshoe wipers are usually bad on an old game, and I've had a hard time finding old stock of these to rebuild old drops. I have ended up grabbing parts from a bunch of old drop banks to get 2 working banks rebuilt.

    Good old games to part out to get drop targets: Disco Fever, Hot Tip, Phoenix.

  2. Obtain 2 "10-point" leaf switches. These can easily be from an old playfield, or wherever. Make sure that you get the kind that have the mounting bracket extending out from the BACK of the switch.

  3. Remove the old standups.

    Unscrew the switches from the playfield, and carefully desolder the wires. Save the old switches if they are in good condition, especially if the decals on them are good. You never know when you might have another Firepower that needs fixing up. You might even want to keep TWO Firepowers -- one with standups and one with drop targets -- just so you can do a side-by-side playability test.

  4. Make U-shaped cutouts for "10-point" switches.

    Drill/route/cut a cutout behind the two bank locations to accommodate the "10-point" switches. Neatness counts here.

    Make sure you have space to actually mount the switches.

    This area of the playfield is rather cramped.

    Mount the switches after cutting is complete.

  5. Mount drop target banks.

    As noted above, the playfield is a bit cramped. This is further complicated by the fact that the two target banks are angled toward each other. I had to do some cutting of the target bank assemblies to get them to fit. A Dremel tool with a cutting wheel works well for this.

    As I recall, I had to cut off one or more of the mounting feet on one or more of the drop target assemblies.

    Again, neatness counts. Be sure to center the targets themselves within the oval cutouts and align them nicely. A sloppy job will only bring you the ridicule of your friends as you show off your work.

  6. Wire drop target reset coils.

    The backbox wire harness brings the solenoid wires up to the connector that mates with the playfield harness. To do a really neat job, find some Molex-type pins to insert into the playfield harness connector to bring the signals down to the playfield.

    If you connect directly into the backbox harness, you will not be able to remove the backbox when you have to move your Firepower through a narrow doorway.

    (I was able to work the pins out of the connector on the above- mention Disco Fever harness, and use the whole wire for the conversion.)

    Wire the drives to the lug of the coils that are connected to the anode of the diodes (side WITHOUT the stripe). Refer to another coil on the playfield to double check.

    Connect power to the coils. Use a Red wire and tack on to a nearby coil. The power goes to the coil lug connected to the cathode of the diode (side WITH the stripe).

  7. Wire the switches.

    The drop target switches are wired in the same place in the matrix as the standups. That information is as follows, from left to right:

    The early style drop targets (horseshoe/wiper) had two sets of contacts -- momentary and continuous. The momentary are activated while the drop target is on its way down, and the continuous are activated while the the target is resting in the "down" position.

    The easy way to connect the drop targets is to simply use the continuous contacts on each target and connect it as listed above. This is the way later style (Black Knight and later) drop targets would be wired.

    The original Firepower, however, used the momentary contacts connected as above. The continuous contacts were connected in series within each bank, and connected into another place in the matrix. This gave the software an extra piece of information that all the drops in a bank were down. You can connect your drop switches this way, but its extra work that is not necessary. Here are the switch positions:

    The "10-point" switches are wired as follows:

    When wiring switches, note that the White wire is connected to the anode of the diode (side WITHOUT the stripe), and the Green wire is connected to the switch terminal NOT connected to the diode. Refer to another switch on your playfield as a guide.

  8. Double check your work.

    Especially make sure that your coils are wired correctly.

    If you reverse the leads on a coil, you will blow up the solenoid driver transistor. The Red (power) wire goes to the coil lug connected to the cathode of the diode (side WITH the stripe).

    Check the wiring of the switches. If switches are incorrectly wired, they can mess up other switches in the matrix.

  9. Test your work.

    Run test mode on your game and check out the solenoids and switches to verify the correct installation.

  10. Play your game.

    Notice that the default "light kickback" rule now makes more sense: The kickback is lit on "1-3" or "4-6" on the same ball or spotting the "1-6" lamps. Now that you have drop targets, you can actually keep track of the "1-3" or "4-6" on one ball.

  11. The drop target stickers used on Firepower depicted the "melting man" as shown elsewhere on the game. They sport the part number 30A-7572. I have seen these stickers around, so they should be obtainable if you look hard enough. My guess is that several rolls of these stickers were printed, in anticipation of the production of the game with drop targets.

    Since none were produced that way, that means that there should be quite a few stickers floating around somewhere. (I found a few at a local distributor who was kind enough to let me poke around on his shelves. He must have just gone down a list of sticker part numbers and ordered a bunch at one point.)


Written by Edward Estesestes@MCS.COM
Document converted to HTML by David Gersic info@zaccaria-pinball.com