Wondering if anyone can post a closeup pic of the CPU connectors A1-J6 & A1-J7 from a Countdown machine?
I recently re-pinned those two connectors & I'm certain I have it wired wrong.

Thanks for the pinout. Seems the wire coloring is different on countdown?
Here's a couple of pics of A1-J6 & J7 that I rewired, Can anyone confirm if this is correct?
a1-j6.jpg
a1-j7.jpg

Thanks for the help so far guys.

I don't have a manual or schematic for the game, No digital copy freely avail either of course.
Just been using Clay's system 1 repair guide.

Checking my wiring against OTTOgd's I have A1-J6 correct, A1-J7 pins 1-4 correct but was incorrect on pins 5 thru 17 with each of those wires being in the wrong spot one away from where it should be.

Currently I can't get the gameplay to actually start so hopefully once I rewire A1-J7 I'll be able to finally start a game!
Will check back with an update & thanks again for the help.

Well I rewired A1-J7 as per OTTOgd's picture above (All wire colors match).
I turned the machine on & after the standard 5 sec bootup delay all 4x displays show all zeros (Solid) while the small credit display shows nothing, Pressing the start button does nothing as before.

Turned machine off then back on, Normal 5 sec delay then all 5x displays including the credit display show all zeros but now they are rapidly cycling on/off each segment. Pressing start does nothing (Machine is wired to freeplay).

I need to upload both videos so you guys can see & will try to do so shortly.

Ok I have finally uploaded both boot up videos of my Count Down.
When I boot my Count Down machine I get either of the two results.
Any ideas as to what the issue here is?

I have the slam tilt bypass mod on the cpu in place

Yes all stock system 1 boards, Nothing by pascal or niwumph.
Replaced all caps on power supply board, Replaced all transistors on driver board & completed upgraded ground mod to that board. CPU board had corrosion damage from leaked battery. Repaired corrosion damage, Completed remote battery pack mod, Slam tilt bypass mod, New CPU to driver board wiring harness, Replaced all of the ICs along the bottom of the CPU board & the ground mod to each board also.

When I first received the machine & turned it on it went straight into slam tilt error (All zeros with no 5 sec delay)
After doing slam tilt bypass jumper wire it turned into what's seen in the videos above.

No switches work, The start button, The white diagnostics button inside the coin door, Nothing.
I've traced the wiring out & all is good. No high score to date on the displays, I've only seen the number zero.

Also want to add that this is my first & only gottlieb system 1 game & I have no access to any other so I can't test these boards in another working system 1 machine.

SadSack to avoid any confusion please don't hijack my thread, I believe cro_pinman is referring to the situation with my machine which has it's own unique problems.

I do hear the click-click of the relays on boot (I think you can hear in my videos)
Don't have a logic probe but do have a DMM
Soldering skills aren't a problem, I use a Hakko 808 to desolder ICs.
I have J6 wired correctly I believe.

Here's a pic of my CPU board. I replaced a number of IC's on the board (Shown in pic with green dots) a couple of weeks ago (Before starting this post).

sys1_cpu.jpg

Gave up on the original CPU board & ordered a replacement from Pascal Janin.
Still sure there will be other problems such as 2x of the drop target banks not working.

Recieved the Pascal CPU board last week & (Just about) everything works!
Should have purchased one of them from the start, Oh well.

The problem I have is that the 2x left side flippers don't work.
Would this be a problem with the cabinet flipper button switch?
The wiring all looks good, Still yet to check the coil diodes etc.

To close this thread the game is now working 100%, Flipper issue was due to a plug inside the cab.
Thanks to all that helped.