williams system 11c mpu upon power up diag led flashes 60 times then blanking flashes 10 then nothing

[hawk007]

Hello there everyone. When I power up my game show 11c mpu , [on
bench or in game] the 5 volt led is always on, the diag led flashes 60
times exactly then the blanking led finally comes on and flashes
exactly 10 times then everything goes dead except for the 5 volt led
which remains on. WHAT DOES THAT MEAN??????? cpu test switch does
nothing . unplug and repower...same thing ...over and over.
replaced 555 timer chip, checked pia's, all good, replaced 6116 ram
to no avail? any ideas. Thanks for any help!!

[beaver]

In cases like these, when the LED indicators are doing something
completely unexpected, I suspect that the ROM access is bad. The code
is just going and executing randomly until it just crashes.

Contact me if you want me to take a look at this board.

Edward Cheung CARGPB26

Hello there everyone.  When I power up my game show 11c mpu , [on
bench or in game] the 5 volt led is always on, the diag led flashes 60
times exactly then the blanking led finally comes on and flashes
exactly 10 times then everything goes dead except for the 5 volt led
which remains on.  WHAT DOES THAT MEAN??????? cpu test switch does
nothing .  unplug and repower...same thing ...over and over.
replaced 555 timer chip, checked pia's, all good,  replaced 6116 ram
to no avail?  any ideas.  Thanks for any help!!

[GuilfordBob]

Hello there everyone.  When I power up my game show 11c mpu , [on
bench or in game] the 5 volt led is always on, the diag led flashes 60
times exactly then the blanking led finally comes on and flashes
exactly 10 times then everything goes dead except for the 5 volt led
which remains on.  WHAT DOES THAT MEAN??????? cpu test switch does
nothing .  unplug and repower...same thing ...over and over.
replaced 555 timer chip, checked pia's, all good,  replaced 6116 ram
to no avail?  any ideas.  Thanks for any help!!

I had virtually the exact symptoms (60 diag flashes, followed by 5 on
the blanking). It was the RAM. could be connections & not the chip.

[leon]

This would be diagnosed in less than 5 minutes using the test eprom
Leon fromù http://www.flipper-pinball-fan.be bn

Hello there everyone. When I power up my game show 11c mpu , [on
bench or in game] the 5 volt led is always on, the diag led flashes 60
times exactly then the blanking led finally comes on and flashes
exactly 10 times then everything goes dead except for the 5 volt led
which remains on. WHAT DOES THAT MEAN??????? cpu test switch does
nothing . unplug and repower...same thing ...over and over.
replaced 555 timer chip, checked pia's, all good, replaced 6116 ram
to no avail? any ideas. Thanks for any help!!

I had virtually the exact symptoms (60 diag flashes, followed by 5 on
the blanking). It was the RAM. could be connections & not the chip.

[hawk007]

Post by leon
This would be diagnosed in less than 5 minutes using the test eprom
Leon fromùhttp://www.flipper-pinball-fan.bebn

Hello there everyone. When I power up my game show 11c mpu , [on
bench or in game] the 5 volt led is always on, the diag led flashes 60
times exactly then the blanking led finally comes on and flashes
exactly 10 times then everything goes dead except for the 5 volt led
which remains on. WHAT DOES THAT MEAN??????? cpu test switch does
nothing . unplug and repower...same thing ...over and over.
replaced 555 timer chip, checked pia's, all good, replaced 6116 ram
to no avail? any ideas. Thanks for any help!!

I had virtually the exact symptoms (60  diag flashes, followed by 5 on
the blanking).  It was the RAM. could be connections & not the chip.

Hello Everyone
Well I got LEON test eprom and did the tests. everything is fine but
the u25 memory test fails. The chip has been replaced and the
voltages at the legs at u25 are all reading higher than the readings
he gives for the chip.? What would cause that?
HELP!
To top it off I just broke my z1 zener. I will need another one. DOH!
Thanks so much for any help.
Hawk