STTNG electrical problem please help

Nevus

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I have an STTNG problem that I can't seem to lick.

I have been restoring it for a few months. I've rebuilt cannons, replaced plastics, added lasers, replaced small optos etc. I was building confidence. The game worked and played. Most, if not all problems were rust, switches and playfiled parts. Attempting to diagnose a non-working flasher, It happened.

The right side flasher next to Klingon target bank was out. I wasn't sure where the bulb was. I put it in test mode. Opened the door. Lifted the playfield. Removed the live bayonet with a non working bulb. I couldn't get the bulb out. So I pulled out the bayonet and touched it to the Klingon 3 target bank. There were some sparks. I said oops. I had no idea this was very very bad.

I turned off the game and replaced the bad bayonet and bulb (old one was rusted). Turn on game and get "fuse 114 and 115 out". Fuse 114 was not out. Fuse 115 was out. 3/4 amp slo-blow. Replace fuse and get "Ground short Row 1" Consensus from forums was that I have damaged my CPU board ULN2803. Sent it for repair by Chris Hibler. After installing, game does not work. It boots and a series of really bizarre things happen. Chris was very helpful taking me through some diagnostics.

The Game Boots and
DMD says "Testing 50023 REV LX-7", "Press enter for test report". then goes to picture of enterprise and title screen. Cannons continue to look for home and coils fire. Opening the coin door, the buttons do not work in a normal way. The right button labeled enter or test does not work. Volume buttons do not work. The escape or service credit buttons work. The game is stuck on maximum volume and will only reset if I remove the batteries. After removing them, the game will boot and eventually the volume will increase to maximum as if the button is continuously pressed.
Left and right flipper buttons act as coin door buttons.
The flashing start button does not respond
Continue button does not respond.
I cant get to the test menu so I assume I have melted something together that shouldn't be.

After trying a bunch of tests, the coin door buttons appear to be in continuity with the molex connectors that attach them to the CPU board. I send off the following boards, Fliptronics, 8 driver, multi-opto (beneath playfield) and the DMD board (wasn't suspect but because it looked cooked). After evaluation, they all appear to be fine.

So, I now have my boards back and am stuck. I would really appreciate advice at this point and would gain great satisfaction from solving this with said assistance.
Although not related to the incident, I made several repairs after my electrical mis-hap that I had planned to do. I include this in case it helps. I replaced the 7 opto boards in the trough, rebuilt all 3 flippers with kits from marcospec, repaired a few bad lamp sockets on the large lamp board beneath the Enterprise on the lower playfield.

Thanks everyone,
Chris
 
If certain items are acting as others sounds like you have a connector on the wrong header. After all, the volume switch is simply a momentar switch and so is a leaf switch right? Or possibly being a pin off could case it. Go back over your cables and ensure you haven't plugged one in backwards or even a pin off. If things are working you haven't blown out the transistor (or other components) in the immediate circuit.

If the volume keeps increasing it could very well be the ASIC CPU chip is hosed.If you have any other machines try swapping the ASIC chip out (of course compare part #'s first). If you end up cooking that chip those can be had relatively cheap anyway.
 
I dont see any corrosion or anything odd accept no battery holder.
I will check my TZ tonight and see if the connections match up
i do think both games are the same in the connections.
 
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I think i found your problem Chris,j206 and j208 should not have any
connectors on them.Place the connector with the greens wires to j207
and the connector with the white,blue,orange to j209.This photo is from
my TZ machine and they do have the same connections.Give it a try and lets
hope it works and let us know.Thanks,Mike
 

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looks like your cpu board has been repaired for a leaked battery in the past, maybe this has not been done well and some damage is still hidden somewhere under an ic..

anyway test/volume buttons are direct input switches, these are on the left,
switch matrix are the 2 connectors on the right and have nothing to do with the symptoms you have

have the cpu sent off for repair/check
probably one of the ic's for the direct switches is bad

btw the pinwiki.com wpc guide already has some info about the direct switches
 
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Thanks everyone for the replies. The board was just repaired and the corrosion repair was part of that.

During my previous efforts to repair the board, I have taken this board and tested it in my TZ with swapped roms. It worked perfect.

As for location of the plugs, I will try tonight but I'm fairly certain this is where they always were on my STTNG.

Is it possible that the connectors or the wires leading up to them could have been affected?
 
This info is from STTNG manual and you can see J207 and j209 should be connected
 

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Electronically speaking.....J206 and J207 are the same......as is J208 and J209. It doesn't matter which of the two you use.

Edward
 
if you test the cpu and it works in your TZ and direct switches have no problems, then it must be something with the wiring on the switches.. there isn't anything else in that circuit.. see if the buttons themselves are dirty/sticky ?
 
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