Discussion:
Really Weird Williams System 11b MPU Fault
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wozzer
2016-02-19 10:08:56 UTC
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Hi,
Am working on an Earthshaker that has an odd fault, usually the pin works ok, but about 1 in 10 power ons I get a weird fault where I switch on and get a tone but no attract mode on the lights and nothing on the display.
On the 3 diagnostic leds, the left one is on, and the centre one keeps flashing (nothing on right hand led). The centre led flashes for about 30 seconds then a message comes on the display something like '+@#?/+ FAILURE' then the pin seems to reset itself and comes on fine. Has anyone seen this fault before? Thanks.
t***@gmail.com
2016-02-19 13:41:23 UTC
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Post by wozzer
Hi,
Am working on an Earthshaker that has an odd fault, usually the pin works ok, but about 1 in 10 power ons I get a weird fault where I switch on and get a tone but no attract mode on the lights and nothing on the display.
Battery damage?

viperrwk
John Wart, jr
2016-02-19 14:00:21 UTC
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Post by t***@gmail.com
Post by wozzer
Hi,
Am working on an Earthshaker that has an odd fault, usually the pin works ok, but about 1 in 10 power ons I get a weird fault where I switch on and get a tone but no attract mode on the lights and nothing on the display.
Battery damage?
viperrwk
I would also check for battery damage, I'd also check your +5 and +12
and see how close they are.

I've seen questionable +5 cause odd faults before. Sys11 is not as
finicky as WPC, but it can cause problems.
Gott Lieb?
2016-02-19 14:36:39 UTC
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Post by wozzer
Hi,
Am working on an Earthshaker that has an odd fault, usually the pin works ok, but about 1 in 10 power ons I get a weird fault where I switch on and get a tone but no attract mode on the lights and nothing on the display.
If it's clean, I would suspect corrupted RAM.

Jim
wozzer
2016-02-22 10:00:55 UTC
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Post by Gott Lieb?
Post by wozzer
Hi,
Am working on an Earthshaker that has an odd fault, usually the pin works ok, but about 1 in 10 power ons I get a weird fault where I switch on and get a tone but no attract mode on the lights and nothing on the display.
If it's clean, I would suspect corrupted RAM.
Jim
Hi,
Thanks for the replies, it had battery damage but I have checked everything connectionwise, I measured the 5volt and it was 4.89v, so I changed the bridge rectifier on the psu and I haven't had the fault occur again yet so I have my fingers crossed that this was the problem.
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