Hello Everyone,
Ive just pulled my BK out of storage and its having some strange issues. when powered on it comes up in test and i have no mpu controlled lighting and will not go into play mode i can run all the tests but get the following strange issues.
Display test works correctly.
on the sol test everything looks to be working but when it gets to test 11 every GI light flashes and then it continues the remaining tests is that normal ?
the sound test works correctly.
the lamp test does nothing.
the mpu board led display is blank and if i press the diagnostic test switch it displays 0 briefly.

Anyone have any pointers where i should look or for what the possible issue can be ?

Everything was working when it was put in storage. although it did get moves around a few times.

Thanks
Bruce

Update:
I managed to get the lights working. found a shorted lamp socket which took out F3 fuse corrected the issue and that fixed the lights.
now it sits in attract mode and will not coin up its also displaying 03 in the match window if that helps.

Thanks
Bruce

Update,,,,
I tried checking the switches and found that none of the ball trough switched register as well as the credit /start button.
but all other switches do respond but when i hold a switch down the display shows multipul switch locations for many of the switched . What could cause that ?

Thanks
Bruce

a little further testing and i found the coin slot switches dont register either and all but the first drop target section will not pop up they get a weak pulse and thats it. i did check the wiring in several places and it looks like its ok and cant find any thing that looks incorrect . all flippers work correctly.

Thanks
Bruce

Awesome thanks,
I'll check it out later tonight.

Bruce

I checked all the wires and it is good i pull the connectors off and let it set for a few seconds and then it starts randomly seeing inputs form rows 4 and 6
I removed the chips and replaced with a socket and new chips and still doing the same thing .
Could this be power related ? or possibly the pia chip ? or a resistor ?

Thanks
Bruce

Thanks for the info. the MPU and 40 pin connector were rebuilt not to long ago so im pretty sure its not that, I'm thinking its the PIA chip i noticed that it seems to be heat related or at least time related if i let it sit for 20 min the power up and go into test with connectors off nothing is on but within 3 minutes several rows and columns are showing up and its always the same ones all of row 1 and 4 Ive changed the 7406 and 4049 chips and get same results. the PIA has been socketed by previous owner so at some point there must have been issues. Its just strange to me that all was working when i bought it a little over a year ago the it went into storage until now and these crazy things start happening LOL
another issue ive noticed is the top two target banks don't always reset properly .

Thanks
Bruce

Update:
I replaced the PIA and everything is working now except switch 17 in the ball trough. the switch tested good. Could it be a bad diode?
Ill test things over the next few days and update what I find.

Thanks for all the help

Bruce

Finally got some time to work on the knight .. got the switch 17 issue resolved was a bad wire on the idc connector re punched and fixed the issue .

now i have to figure out why the 2 ball hole dosen't fire. it knows the ball is in the hole but it never fires. Ive checked the wiring and connectors so im thinking its a transistor any tips to checking ?

Thanks
Bruce

I checked the transistors and Q28 was reading kinda funny so i replaced it with a 2n4401. still not working but now Q28 and Q29 HOT like burn your finger hot. The coil is not even warm. So is something stuck on or did i not use the correct replacement for Q28 ?

Thanks
Bruce

i also checked all the resistors R51 reads 68 R50 reads 553 and R52 reads 2.7K i did check a few others in the area and they all read similarly with the exception of the 2.7k is only 1.7 K on R43,R46,R49 .

BK is back to fully working I removed the coil to verify it wasn't shorted and checked that the diode was also good. both checked ok upon reinstalling the coil I realized that the previous owner had installed the wiring backward so the diode was not properly wired I wired it correctly and turned BK back on and everything works correctly. I'm just a little confused as to how it could have been working when I bought it then it sits for a little while before I can get it set back up and when I do get it set back up it starts acting funny and not working correctly with no real signs of bad components but when I changed the funny reading transistor to correct what I thought might be the issue it made it worse, lol.
Another lesson learned
Thanks to everyone for all the information and helpful suggestions.

Bruce