Re: Tech: No +5V on Pole Position Video Board?

It was a loser error! Since I had crimped on a new edge connector for
the video board, I was following the schematics... and I mistook
"8" (unused but really ground) for a "B". So I had created the short
and that's why it wasn't reading +5V but instead 0V. I recrimped the
B pin and now the video board has power. Now I have to deal with the
garbage on the screen...


On Jan 9, 10:40 pm, James Sweet <jamesswe...@xxxxxxxxxxxxx> wrote:
t...@xxxxxxxxxxxx wrote:
I'm restoring a cockpit Pole Position with PP2 boards.  I installed
the Bob Roberts cap kits for the two AR II boards as well as replacing
"Big Blue", the bridge rectifier, and fuse block on the power supply.
PP2 came up with random characters on the screen -- good!  I turned
the game off, turned it back on, and now the video board LED doesn't
light up.  I checked the +5V test points on the video board, and they
read 0.0-0.2VDC.  I get the same reading at the AR II board that feeds
the video board. I checked the 10.3V unregulated on the AR II board,
and that is fine.  I swapped AR II boards (since the "A" AR II board
was giving +5 fine to the MPU board) and the video board still doesn't
have +5.  I did the usual things... put on a new 15/30 edge connector
for the video board's wiring harness, check connectivity on the wiring
harness between the video board and AR II "B" board... all looks
fine.

Any ideas where I should start troubleshooting?  Does this sound like
a short?  I have been researching and scratching my head over this
one.  Can the video board cause the AR II *not* to supply +5V if there
was a bad resistor or diode in the power circuit (where the LED is) on
the video board?

Tony

Are you *sure* both ARII boards are working? The 2n3055's fail sometimes
and result in no +5V.

.