Problem with Police Trainer... I don't think it's the guns

davebach

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Problem with Police Trainer... I don't think it's the guns

Hello,

I am very glad to find this forum. I've recently come upon a Police Trainer from P&P Marketing. It's in good condition, but needs some loving. It does NOT seem to be in the original cabinet based on other images I've seen (it is a two-piece cabinet, the smaller console holds the guns) and contrary to posts that I have found that says the version number topped out at around 1.3, this one announces that it is version 1.5 when you turn it on.

I'm having trouble with the red gun... I'll give you a bit of backstory. I was told by the former owner that the Red gun (Player 1) was dropped one day a while back and then never worked again. So I bought a new red gun online, even before I got the thing into my garage, figuring it was the optical PCB or the light. I figured since I'm new to this, I'll start with something that I know works, and work backwards to fix it. But I don't think it's the gun.

I stumbled upon the service menu (I think after disconnecting the gun it turned on after a bit!? Since then, I have found reference that dip switch 1 will turn it on, but have not tried that... I also saw reference to a test or service button, but the board or cabinet does not seem to have that).

The gun trigger sets off the "flash" but the shot is not registered. In the service menu, everything checks out (the gun "switches" work, ROM checks, and other diagnostics) but the verify and calibrate guns menu is where it fails. The right player 2 (blue gun) works fine. The left player 1 (red gun) does not register a cross hair... on any brightness level. If I swap the guns at the PCB, the red gun works as player 2, but now the blue does not register as player 1. So both guns are good, something else is broke.

I don't post without searching and reading a forum first, so I've tried some of the other suggestions here... I've swapped the gun connections on the PCB, I've tried them in various lighting conditions and brightness levels. I checked the power out of the gun connectors on the board, and they both give off 5v.

Not sure where to look next. Any help would really be appreciated.

Thanks,
Dave
 
If you swap the guns and the problem does not move, then its a board problem..

I think someone posted you can remove the gun interface board and plug the guns directly into the pcb. But you should verify that before you try it..
 
If you swap the guns and the problem does not move, then its a board problem..

I think someone posted you can remove the gun interface board and plug the guns directly into the pcb. But you should verify that before you try it..

It's actually an amplifier board to increase the guns accuracy. They go
bad all the time, and you can plug the guns into the main board
without it, they will work fine.

JD
 
It's actually an amplifier board to increase the guns accuracy. They go bad all the time, and you can plug the guns into the main board without it, they will work fine.

JD

I don't think this has an amplifier board. The guns are attached to the *only* board. I've attached a pic for reference just in case. You probably already know this, but it's the connector on the lower right in the photo labeled CN1... either gun attached there does not work.

Dave
 

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Follow the trace from the data line on the gun to find the chip it goes to... replace the chip.

I had a Lord of Gun that was intermittent on the gun and it was a bad 74LS14 chip which is a schmitt trigger designed to sharpen up the signal coming from the gun. Maybe you have something similar.

Hope it's not like an Egg Venture I repaired which had NO gun inputs working. The guns on it went straight into a very expensive Xilinx FPGA chip without any input protection AND the armored cable on the gun wasn't grounded. The board came in with a description of "got a zap from the cable and the guns stopped working"... yeah... the cable didn't zap, they zapped the cable and it fried the FPGA.

I replaced the FPGA chip on that game then told the oper to ground the cables to the guns or it would fry again.
 
Thanks for the advice. The optical trace goes to a chip that is soldered onto the board... that's a little beyond my soldering abilities.

Is my only other option to replace the whole board if I can't fix that? Perhaps someone could point me in the right direction... maybe to someone who fixes these or will swap a bad board for a good one (for a price, of course). I see that this site has a great deal of information on people selling boards, maybe that is my best option.

Dave
 
What are the numbers on the top of the chip?

I won't be able to check that again until Friday, but I do appreciate the help.

BTW, just read through some of your repair logs... maybe I'll practice on some old boards and see how I do :)

Dave
 
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Thanks!

Practice is the best way to hone your skills before trying to replace a chip on a board you want to repair - especially doing surface mount soldering.

The key to clean surface mount soldering is the liquid rosin flux. It makes the solder stick to the pins and helps keep it from bridging.
 
I know this thread is super old but I had the exact issue and wanted to provide some pictures for reference. Troubleshooter 1 pic shows the two pins for player one circled. One is the optical pin and the other is ground. These had continuity when testing and they should not. The traces go to location U119 and the chip to replace is 74F320 (pic2). After doing that the game is good to go. Hope this helps someone.
 

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Thanks for this info ! I have 3 or 4 of these at locations I service
and this could come in handy in the future !
 
I have a similar issue but when i plug both guns in and fire gun 2 it always hits where gun1 is aiming. Anyone have ideas?
 
I know this thread is super old but I had the exact issue and wanted to provide some pictures for reference. Troubleshooter 1 pic shows the two pins for player one circled. One is the optical pin and the other is ground. These had continuity when testing and they should not. The traces go to location U119 and the chip to replace is 74F320 (pic2). After doing that the game is good to go. Hope this helps someone.
I wanted to mention I typo-ed the chip number. It is 74F32D. The D looked like a 0 since the chip is so small but under a magnify glass it is for sure a D. Sorry about that folks!
 
No problem.
Those in-the-know will likely have recognized that there's no such IC as a 74F320, and that "D" is a common suffix for SOIC packages. ;)
 
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