Hello all, my first post on this forum.
My first post since 15+ years on any forum... The Arena made me post this.
this week I purchased a Gottlieb Arena that hadn't been powered on for a long time.
During the purchase we decided to try our luck and powered on the Arena. The main fuse of the house went click and no more electricity.
I took a chance and bought it anyway
Arrived at home I first checked the fuses, all test ok with DMM. Power supply diode bridges test OK.
5 volt has been set to 5.03 at prom 1. The first few times I started the Arena the displays turned on, I got sound and a few lights flashed and solenoids clicked. The displays showed nothing meaningful, zeros mixed with '-' and spaces. There was battery leakage so I removed the old Varta and cleaned the surrounding area. The reset board has been disconnected and the resistor on the reset board connector soldered on the back of the MPU (as described on PinWiki).
After cleaning I get almost nothing. No more displays, sometimes at boot it wil beep for 1/2 second in repeat. Sometimes 1 continuous beep, and when I get lucky I get the startup sound.
U4 gets really hot (also when only the MPU is connected), I read on this forum that it could explain the boot process not completing. I will replace U4, U5 and U6 just to be sure.
The main reason for this post is the modification that has been done to the MPU. On PinWiki I found a paragraph under Gottlieb System 80 B about "Using a 2732 at the PROM2 position in a System 80B MPU".
It looks like this mod has been applied, but not completely. The jumper from TC1, pin 35 to the right solder pad of the cut trace is in place. But jumper E4 has not been removed and the board is still equipped with a 2516 PROM (2516 Texas Instruments is equal to an other brand 2716).
According to the service manual 2716 PROM 2 is correct. So why this jumper from TC1, pin 35? Is it a factory modification? Has anybody seen this before on a System 80 B?
I wonder if it will ever boot with this incomplete modification
I ordered new RIOTs for U4 5 and 6, will try again after they have been replaced.
pictures showing the mod attached.
Looking forward to hearing from you, Phil.