Hi everybody! I'm trying to repair a Bally -17 mpu from an old Mata Hari.
The board has some acid traces, but I've cleaned up well all the area.
So, I burned the Leon test rom ti be placed in U6 and the LED flickers as per manual.
I've installed U9 (6800), U10-U11 (6821), U7 (6810).
Once I put the U8 (5101) the LED is stucked solid on always with test rom.
Also the same story with both 2716 that I've burned with ipdb images.
The 5101 Is ok because working in another machine. The eeprom are verified with GQ programmer..
Any suggestion?
Thanks in Advance

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Hi! Yes, I have another ones to try and I will follow your hint.
But the program should go on indipendently from other chips.
From Leon's Borre page:
"This program does not lock-up. This means if an output of a chip is bad, the program will continue to work. This way you're able to use a led in series with a 2Kohm resistor,a multimeter or a logic-probe to read all outputs of chips and know if everything works. To have some means of control that the program runs ok , we connect a control-led who will flash in rhythm with the test . The led on the cpu-board will also flash, because it is tied to the signal CB1 of U11, this of course if U11 is working normally.
This test checks only Cpu 6800 (U9) and both 6820 chips (U10 and U11) and is not dependent on memory chips (U7 and U8) and of no game-specific eproms (U1, U2, U5, U6)"
From the moment the program is stopped when the U8 (5101) is installed... Where I am wrong? Also for U2 & U6...

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So, checking again the board now has troubles in the reset section.. sometimes boots, sometimes not and jumpering pin 39-40 of the cpu, the led starts to blink.
But with 5101 the led is always on, despite the trick.
With multimeter the traces under the 5101 are ok, and the lamp confirm that..
The path is good from every pin of 5101 to the correspective pin..
I'm stucked. I have to change hobby