Hello guys! I'm becoming crazy with a data east last action hero, since I have involved another machine for test I'll call the non working machine LAH-1. After full shopping I noticed that LEFT JET BUMPER doesn't fire. Watching and measuring the related Q11 transistor TIP122 on the CPU board it looked fine, no sign of burnt neither on the solenoid. Here what i did:

- Having another working LAH (I'll call it LAH-2) on hand, I did a CPU board swap to try isolate the problem. With the "new" board on LAH-1 the coil fired in test many times, I tried to start a game and here it fired 2-3 Times before dying again.

- I then installed the CPU from LAH-1 on LAH-2 and the bumper didn't work at all. I assumed that the q11 and related predriver need to be replaced..and so I did, with the replaced component the LAH-1 board works on LAH-2.

-Assuming that the bumper coil on LAH-1 was burning tips on my boards i replaced it with a new one as from manual. I replaced also the Tip122 and predriver from the board (this is the one originally installed and fully working on LAH-2).

Again I have tryed the solenoid in test mode and it fired many time without apparently a problem. Started a game and after a few match I started to smell burnt..

The transistor I have just replaced was melting and the new replaced coil was really hot!

At this point I really don't know what else it could be.. measured the related resistances on the board and they looked fine, the bumper related switch only register when touched so it won't stay on energizing the coil, also the coil diode is not broken (it's new!)..

Please help! there is something obvious I am forgetting to check?

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Yes! In one side it gives different increasing values and in the other it is between 058 and 060 measuring with the multimeter on a scale of 200 ohm..anyway the coil is new from shop!

Bump!