pooman2084
Be Attitude For Gains!
I've been getting intermitent joystick problems on Robotron.
Pushing the ribbon cable that goes from the widget board to the main CPU board would correct it, but over a few hours or sometimes weeks, the controls would go again.
I left the job as it looked like you had to unsolder something from the widget board, and I'm loathe to start pulling the cab apart as the only mod / repair it has had from new is one RAM chip!
Today I stumbled across Dave Langley's repair log whilst looking for info on a power supply board and noticed this:
Section 3: Widget (Interface) Boards
Widget (Interface) Board 1: Sinistar
Symptoms:
No reaction to switch inputs or oc
casionally intermittent reaction to them.
With the board connected to my test bench and powered up in switch test mode I started
probing around. When the ribbon cable is wiggled, the inputs start flashing on and off:
Clearly this is a bad connection on the ribbon cable, this is quite a common fault. I have
seen it at least three times on interface boards and once on a ROM board. Most of the
boards I get have been in storage for up to ten years and some have not been stared very
well. It is quite normal to find boards with impact and/or storage damage.
Its easy to check for bad connec
tions with an ohm-meter, but be sure that you are moving
the cable around while you are doing it otherwise you may not spot an intermittent
connection.
It is also an easy fix. If the ribbon is not damaged then gently pry open the covers at both
end of the cable and gently squeeze the IDC contacts onto the wires to ensure a good
connection. Replace the covers and try it!
If the cable is damaged it will have to be repaired or replaced.
Theory:
With some of the cable inputs/outputs missing then the game will not get all the
signals it was expecting.
Notes:
I have seen this fault three times, but it could be possible for other symptoms to
also be the ribbon cable. I seem to remember from the distant past I fixed an interface that
was holding a CPU in reset by replacing the ribbon cable ...
I very carefully prized off the ribbon cable cover (I didn't even know it came apart!), sadly two tiny blue tabs snapped in the process as they were incredibly brittle, but they do not keep the tension, so it should be ok.
Anyway, I pushed the cables down individually, put the cover back on, powered up and hey, it works!
Thanks AGAIN to Dave Langley!
Pushing the ribbon cable that goes from the widget board to the main CPU board would correct it, but over a few hours or sometimes weeks, the controls would go again.
I left the job as it looked like you had to unsolder something from the widget board, and I'm loathe to start pulling the cab apart as the only mod / repair it has had from new is one RAM chip!
Today I stumbled across Dave Langley's repair log whilst looking for info on a power supply board and noticed this:
Section 3: Widget (Interface) Boards
Widget (Interface) Board 1: Sinistar
Symptoms:
No reaction to switch inputs or oc
casionally intermittent reaction to them.
With the board connected to my test bench and powered up in switch test mode I started
probing around. When the ribbon cable is wiggled, the inputs start flashing on and off:
Clearly this is a bad connection on the ribbon cable, this is quite a common fault. I have
seen it at least three times on interface boards and once on a ROM board. Most of the
boards I get have been in storage for up to ten years and some have not been stared very
well. It is quite normal to find boards with impact and/or storage damage.
Its easy to check for bad connec
tions with an ohm-meter, but be sure that you are moving
the cable around while you are doing it otherwise you may not spot an intermittent
connection.
It is also an easy fix. If the ribbon is not damaged then gently pry open the covers at both
end of the cable and gently squeeze the IDC contacts onto the wires to ensure a good
connection. Replace the covers and try it!
If the cable is damaged it will have to be repaired or replaced.
Theory:
With some of the cable inputs/outputs missing then the game will not get all the
signals it was expecting.
Notes:
I have seen this fault three times, but it could be possible for other symptoms to
also be the ribbon cable. I seem to remember from the distant past I fixed an interface that
was holding a CPU in reset by replacing the ribbon cable ...
I very carefully prized off the ribbon cable cover (I didn't even know it came apart!), sadly two tiny blue tabs snapped in the process as they were incredibly brittle, but they do not keep the tension, so it should be ok.
Anyway, I pushed the cables down individually, put the cover back on, powered up and hey, it works!
Thanks AGAIN to Dave Langley!
