I bought a BK2K about 12 years ago. I played the game a few times with no issue and then wanted to do a restoration on the play field because it was shot. I finally got a Mirco play field and did a swap and reconnected all the wiring. However, I now have an issue with the Diagnostic LED. I read the manual, however the Diagnostic LED is not following a pattern with a certain number of blinks as indicated in the manual. It instead begins blinking as soon as the machine powers on and does not stop blinking at all. When pressing the start game button, the machine will throw up a "00" on the screen as if a game is going to begin, but it does not kick a ball over to the plunger or make any noise to indicate the game is about to begin. After maybe 10 seconds, the "00" disappears and the machine acts like no game had begun. Instead it just acts as if it is in attract mode.

The machine has been stored in a heated garage over the last 12 years. When I opened it up to install the play field, it still looked perfectly clean. I removed all wires from the boards and plugged them back in hopes it was a bad connection but to no avail.

Any advice would be greatly appreciated.
-Keith

I had taken dozens of photographs before taking the play field out and have matched where everything was plugged into. I took these two connectors off, inspected the pins and all looks good, no corrosion or bent pins or possible issues with the wiring. However, upon reconnecting the connectors, the same issue still exists.

-Keith

I have included a picture of the machines head.

IMG_2832 (resized).jpg

I ended up removing the cpu to find that the transistor ("Motorola 9410-0 R8912") located at position Q6 was bad. I then pulled the CPU from my Cyclone (also system 11B) and swapped out the ROM chips. When I placed the Cyclone CPU with BK2K ROMS in the machine, the same diagnostic LED blinked to no end as it did in the Bk2K original CPU. When I then removed the Cyclone CPU and inspected it, it had blown the exact same transistor located at Q6 on the CPU. I am beginning to think that the BK2K game play ROMs (U26 and/or U27) may be bad. Any help or knowledge regarding this would be greatly appreciated.

Thanks for all the help so far. It has been a long process of tracing the issue. I have gotten all the way back to the Auxiliary Power Driver Board. Finding that 5J11-9 is supposed to be outputting +25Vdc, but it is in fact putting out +41.5 Vdc. No components look to be bad on board. So I believed there may have been an issue with the incoming power. Upon testing the incoming voltage from the power supply transformer to the Auxiliary Power Driver Board. Those incoming wires go to 5J8-(1-4) and 5J8-(6-9).

My readings:
5J8-(1-2) (Schematics at +24Vac) - Actual Reading = +10.7Vac
5J8-(3-4) (Schematics at +24Vac) - Actual Reading = +17.6Vac
5J8-(6-7) (Schematics at +48Vac) - Actual Reading = +18.5Vac
5J8-(8-9) (Schematics at +24Vac) - Actual Reading = +31.7Vac

This lead me to believe that the power supply transformer may be messed up. So I took readings from the power supply as follows:

White (#1) (Schematics at +88.5Vac) - Actual Reading = +18.7Vac
White (#2) (Schematics at +88.5Vac) - Actual Reading = +45Vac
Grey (Schematics at +9.7Vac) - Actual Reading = +7.7Vac
Grey/White (Schematics at +9.7Vac) - Actual Reading = +13.46Vac
Grey/Green (Schematics at +9.7Vac) - Actual Reading = +20.85Vac
Blue/White (#1) (Schematics at +13.5Vac) - Actual Reading = +23Vac
Blue/White (#2) (Schematics at +13.5Vac) - Actual Reading = +14.07Vac
White/Red (#1) (Schematics at +26Vac) - Actual Reading = +33.2Vac
White/Red (#2) (Schematics at +26Vac) - Actual Reading = +13.7Vac
Black/Yellow (#1) (Schematics at +48Vac) - Actual Reading = +44.2Vac
Black/Yellow (#2) (Schematics at +48Vac) - Actual Reading = +3.6Vac

Do these actual readings look correct, because the disparity between actual reading and what the schematics say should be the reading are wildly disparaging.

After figuring out how to properly test the power supply transformer these are my results.

862291A6-1D1E-4F7D-9D0C-77387E4D0843 (resized).jpeg

StillI have 5J11-9 is supposed to be outputting +41.5Vdc, but it is in fact putting out +25Vdc.