The Aussie Pinball Arcade
Aussie Pinball Forums => Technical Matters => Pinball Repairs / Problems & Assistance => Topic started by: PinPal on May 28, 2017, 06:02:22 PM
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Hi all,,
I have done this many times before, replaced globes on my pins allways with the power off.
But today I replaced a globe on the underside of one of the slings with the power on and ^&^ ^.^ ^.^ thinking I was not going to touch anything the game reset and I thought Hmmmm !@#
Now I got two switch row ground shorts on Row 3. and 4.
Kicking my self @.@
My qwestion is have I shorted the switch rows on U20 on the cpu ?
Pinpal.....
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If you remove connector J209 on the CPU board, do the errors remain?
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Will try,
Pinpal..
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Removed J209 from the cpu, did switch test, no change.
Still has ground shorts switch rows 3. and 4.
Pinpal...
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This test basically shows that the fault is on the CPU board, and most likely U20 (ULN2803) as you surmised.
Best to install a socket when you replace this chip, if one is not already in place.
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Thanks for that, have a couple of spare ULN2803 chips but this cpu is not socketed so will have to sent it away to have the socket put in.
Cheers
Pinpal...