Build Your Own Arcade Controls Forum
Arcade Collecting => Restorations & repair => Topic started by: mtarallo on March 02, 2020, 02:54:26 pm
-
Hello and thank you for taking a look.
I am struggling with getting into my Area 51 / Maximum Force Test screen – I want to adjust the volume and other settings. I cant figure it out – I even followed the schematics found Jamma #15 wire – the motherboard has a SELFTEST location for a 3 way switch – but it was busted off. So I soldered a new switch on the board and I found the wire on Jamma #15 (Test) - this wire is in the harness but goes nowhere. it is loose - If I engage the switch - Jamma #15 wire gets 5v. If I disengage - it gets 0. So where does the wire for Jamma #15 supposed go? Is it supposed to just be connected to another switch with a ground? I assume it would go to a button or another switch - but my tests have not worked.
Thank you
-
It should go to ground.
-
I even followed the schematics found Jamma #15 wire – the motherboard has a SELFTEST location for a 3 way switch – but it was busted off. So I soldered a new switch on the board and I found the wire on Jamma #15 (Test) - this wire is in the harness but goes nowhere. it is loose - If I engage the switch - Jamma #15 wire gets 5v. If I disengage - it gets 0. So where does the wire for Jamma #15 supposed go? Is it supposed to just be connected to another switch with a ground? I assume it would go to a button or another switch - but my tests have not worked.
Page 34 of the manual here (https://www.arcade-museum.com/manuals-videogames/A/Area_51_and_Maximum_Force_Universal_Kit_1634032101_Feb_1998.pdf) shows the test switch schematic -- right side, middle of page.
- Just to confirm, are you working on the main PCB or the mounting bracket for the credit, volume, and test switches shown on page 19? (Test switch should be on the bracket, not the main PCB. :dizzy:)
- One terminal of the test switch should be connected to a daisy-chained ground that also connects to the other switches.
- The other terminal of the test switch should be connected to JAMMA wire #15.
- When you press the button, ground is applied to JAMMA wire #15.
- If the switch has three terminals, make sure you are using COM (common) and NO (normally open), NOT NC. (normally closed)
If I engage the switch - Jamma #15 wire gets 5v. If I disengage - it gets 0.
-- This sounds like you are on the COM and NC terminals of the switch.
-- Check the markings on the switch. If they are not clear, power down and check the switch using your multimeter.
Scott
-
Thank you - for your reply.
"Just to confirm, are you working on the main PCB or the mounting bracket for the credit, volume, and test switches shown on page 19? (Test switch should be on the bracket, not the main PCB"
Yes - this cab did not come with the component board - as shown on page 34 - but it seems straight forward - they are momentary switched wired to ground - I was able to control Volume + and Volume - by attaching some wires to the header pins and touching ground. I would assume TEST should do the same for #15 on the board. I enabled the switch - +5 V comes out of the wire I touch to ground and nothing - the attract mode just continues.
I think the test switch just forces test mode - vs enabling the push button the bracket - either way when wired to ground nothing happens - the game just continues in attract mode etc.
Should my Jamma wire #15 have +5V - I assume so - then when touched to ground - I assume it would go into test mode - it does not - nothing happens.
-
Try holding it on for a few seconds.
My A51 is a bit slow going into test mode sometimes.
-
Hopefully, Titch's long-press suggestion will work, but if not . . .
Looking into the manual further, I found the S1 test switch on the PCB (pages 37 and 30) that you mentioned was broken off.
It's the sliding switch above the JAMMA connector and disc capacitors in this pic, right?
If something hit that switch hard enough to break it off, there may be other damage to the PCB like broken traces nearby.
Also, are you sure you used the right type of replacement switch?
- Substituting an SPST for an SPDT could cause a problem, depending on how things are connected.
- I don't have the actual PCB or a PCB schematic to check, so this is just speculation. :dunno
(https://www.gamesdatabase.org/Media/SYSTEM/Arcade/PCB/big/Area_51_-_Maximum_Force_Duo_v2.0_-_1998_-_Atari.jpg)
I was able to control Volume + and Volume - by attaching some wires to the header pins and touching ground. I would assume TEST should do the same for #15 on the board.
The volume controls work like typical "active low" circuits -- applying ground triggers the output.
Grounding JAMMA #15 should similarly trigger test mode, but if it doesn't, that suggests that the fault is somewhere on the path leading from the ground connection on the non-PCB test switch, through the non-PCB test switch, JAMMA wire #15, JAMMA edge connector, PCB edge connector, S1 (test switch on the PCB), and the PCB traces leading to the test mode input, wherever that is on the PCB.
- Not sure if S1 is wired in parallel with the JAMMA wire 15 path or in series with it. :dunno
Scott
-
You all have been very helpful thus far - thank you so much guys
Correct - that is the switch location.
I created a video just so you can see what I am doing:
https://youtu.be/aQuQq6_tKf0
When I got the board - what was left was the 3 contact points (see pic) - the board is in really good shape but you are correct - it is hard to tell if there was any damage to any of the traces.
(https://p0.craigupload.com/m/a735/0/215023.jpg)
Thanks again
-
Well - I just bought another board on eBay - so I will attempt to use that and note the results.
-
When I got the board - what was left was the 3 contact points
That looks like the guts of an SPDT switch. (Single Pole Double Throw)
(https://www.electronicshub.org/wp-content/uploads/2015/09/SPDT-Switch.jpg)
Center contact is COM (common) and a metal piece shorts the center to one of the outer contacts.
- Center to JAMMA-connector-side contact (2+3) = normal operation.
- Center to other contact (1+2) = test mode.
(https://www.zseries.in/electronics%20lab/switches/slide/pictures/construction%20of%20spdt%20slide%20switch.png)
------------
At 1:10 in the video, the fact that you have 5v on the JAMMA #15 wire suggests that there is continuity to the test switch input port.
The fact that neither shorting terminals 1 + 2 of S1 nor grounding the JAMMA #15 wire triggers test mode means that you're probably looking at a bad IC chip or damage between that chip and the CPU.
- Without a schematic or following the traces on an actual PCB, it's impossible to be more specific. :dunno
Scott
-
Mystery solved - got another board from Canada off eBay - swapped the ROMS and Compact flash and now it works as expected - so we will chalk it up to the fact something else was wrong with the original board.
Here is what it should look like:
https://youtu.be/INK2TyxSpuE
In case anyone else runs into this - at least we know it should be a simple exercise - flipping a switching or grounding JAMMA 15.
Thanks all