Museum of the Game® & International Arcade Museum® Forums

I have a Pole Position board set that works perfectly with the stock 6116 ram installed at 7E. The battery was removed and there is no damage to the board caused by the battery leaking.

20250903_161620b.jpg

I am trying to install a Dallas DS1220AB-200+ in place of the 6116 @7E. But when it is installed, I get the dreaded RAM 8 error.

What I have done so far:

Verified I am getting 5.02v at both ends of the CPU board.
Verified I am getting 4.99v at pin 24 of 7E
Verified that pins 18 and 20 of 7E reach 0.06v upon game bootup
Verified the resistor values in the battery backup power circuit are within specs.
Q2, Q3, Q4 tested good. But replaced in case they were failing under load.
CR6 was incorrect value originally (from factory). Installed correct value from manual.
Also verified CR2 and all the resistors around the LED.
Tried a second Dallas DS1220 in case the first was faulty.

When I increase the voltage to 5.05v, the monitor flashes back and forth between garbage on the screen and the RAM 8 error screen.

Any ideas on where to look next?
Back
Top Bottom