AE35
New member
Hi all!
This is the last day I'm working on my System 11B CPU board from my
Earthshaker....then I'll give it the fire axe(or my wife will) and order a
reproduction.
I don't even know where to start. The board started with being flaky, sometimes
booting, sometimes not. When you played for a while the game would freeze with
a bright burning segment on the display.
As of now, I've changed the PIA U41, the blanking 555 and transistor, the CPU's, the
74154 and checked resistors at R55 and R56 and changed the caps at C30 and C29
My PSU in the game outputs 4.95V, but when checked on the board it's 4.92-ish.
When running the CPU board on the bench, with a PC power supply, the voltage
is 5.5V without load on the PSU, and when connected to the CPU board it's 3.9V or
4V. That's quite a drop. This is measured on the CPU U15 and the testpoint.
Changing that PIA was horrible and I've spent way too much time on this board
By the way, the board does have battery damage!
Thanks for your time, I really appreciate it!
Sorry for the blurry image! As you can see only the +5V lights up!
This is the last day I'm working on my System 11B CPU board from my
Earthshaker....then I'll give it the fire axe(or my wife will) and order a
reproduction.
I don't even know where to start. The board started with being flaky, sometimes
booting, sometimes not. When you played for a while the game would freeze with
a bright burning segment on the display.
As of now, I've changed the PIA U41, the blanking 555 and transistor, the CPU's, the
74154 and checked resistors at R55 and R56 and changed the caps at C30 and C29
My PSU in the game outputs 4.95V, but when checked on the board it's 4.92-ish.
When running the CPU board on the bench, with a PC power supply, the voltage
is 5.5V without load on the PSU, and when connected to the CPU board it's 3.9V or
4V. That's quite a drop. This is measured on the CPU U15 and the testpoint.
Changing that PIA was horrible and I've spent way too much time on this board
By the way, the board does have battery damage!
Thanks for your time, I really appreciate it!
Sorry for the blurry image! As you can see only the +5V lights up!