Prior to posting.. I have been reading and using the repair guide on pinrepair.com
The lower right bumper is not working (I'm not 100% sure it ever was since this is a new to me game..) If I read right.. this is the ONLY special coil on this game that is controlled by the driver board rather than a purely electro/mechanical response to the switch like the others?
I followed all the advice in the guide to the point I have a question..
1. I can get the coil to fire touching the unbanded coil lug to ground.
2. I can get the coil to fire by locating the corresponding TIP122 Transistor on the driver board and touching the center leg to the backbox ground.
3. Then the guide says to test the TIP120 (TIP122 on mine) transistor by using DMM black lead to center tab, and Red to either leg. I "should" get .4-.6 volts.
* Well, IF I have my DMM on correct setting, DCV 200, I get -35 one one leg (black dmm lead to center, red to either side leg) and -35 on the other leg.
Obviously not the same as .4-.6 , as a test I tried some of the other TIP122 next to it.. same readings.
So then..
4. I try the 2n4401 pre driver for this transistor.. IF I got the right thing.. the little transistor right above the TIP120??
I "should" get .4-.6 with Red DMM lead to center and black to either leg..
I "get" -4.8 on one leg, and -.2 on the other. Again as a test, I try some of the neighboring ones.. same thing.
On both of the above transistors, I try some others further away and get completely different readings... (maybe those transistors don't fire coil bumpers but other things that have different readings? maybe?)
So.. my questions.. do I have my DMM on correct setting.. DCV 200 ? (using DCV20 max's out)
Are my readings correct ?
Should I just replace both of those transistors and go from there? Or can someone advise something else to figure out whats wrong.. ?
The guide says after testing / replacing them... I need to go to the 7408/7402 chips and solenoid PIA (pain in ass?)
Thanks in advance..
Steve
The lower right bumper is not working (I'm not 100% sure it ever was since this is a new to me game..) If I read right.. this is the ONLY special coil on this game that is controlled by the driver board rather than a purely electro/mechanical response to the switch like the others?
I followed all the advice in the guide to the point I have a question..
1. I can get the coil to fire touching the unbanded coil lug to ground.
2. I can get the coil to fire by locating the corresponding TIP122 Transistor on the driver board and touching the center leg to the backbox ground.
3. Then the guide says to test the TIP120 (TIP122 on mine) transistor by using DMM black lead to center tab, and Red to either leg. I "should" get .4-.6 volts.
* Well, IF I have my DMM on correct setting, DCV 200, I get -35 one one leg (black dmm lead to center, red to either side leg) and -35 on the other leg.
Obviously not the same as .4-.6 , as a test I tried some of the other TIP122 next to it.. same readings.
So then..
4. I try the 2n4401 pre driver for this transistor.. IF I got the right thing.. the little transistor right above the TIP120??
I "should" get .4-.6 with Red DMM lead to center and black to either leg..
I "get" -4.8 on one leg, and -.2 on the other. Again as a test, I try some of the neighboring ones.. same thing.
On both of the above transistors, I try some others further away and get completely different readings... (maybe those transistors don't fire coil bumpers but other things that have different readings? maybe?)
So.. my questions.. do I have my DMM on correct setting.. DCV 200 ? (using DCV20 max's out)
Are my readings correct ?
Should I just replace both of those transistors and go from there? Or can someone advise something else to figure out whats wrong.. ?
The guide says after testing / replacing them... I need to go to the 7408/7402 chips and solenoid PIA (pain in ass?)
Thanks in advance..
Steve
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