Coil on EWF is locked on

[infinite1977]

Hey guys finally fixing some burnt out solenoids on my Earth Wind and Fire. I just replaced burnt out fuse and re-soldered wires for the knocker. When I turn the machine on, the knocker locks on, i.e on all the time. Any suggestions? Also the fuse that controls this is a weird ampage of 1.6amps. What is a recommended fuse for me to use here, I currently popped in a 2.5A which is working

[Homepin]

Most likely the transistor that drives the knocker coil is shorted. Locate which one it is on the driver board and measure it with a multimeter.

[MartyJ]

Re the fuse, always AVOID over fusing as it will kill transistors...

1.6amp is weird....Is it a slow blow fuse?  If so, Greg (RTBB) has 1.5amp which would be fine.


http://www.rtbb.com.au/catalog/product_info.php?cPath=22_201_87&products_id=530

[Boots]

Most likely the transistor that drives the knocker coil is shorted. Locate which one it is on the driver board and measure it with a multimeter.

+1
If you have trouble with schematics, just clip one end of your multimeter on your coil wire and then probe the transistors on the board, you will soon see which one it is.
Follow the guides to test the transistor.

[ddstoys]

Very good tip Boots.

 Off topic but was wondering what happens when you switch your game on?  I finally powered up my Star god the other day before packing it away.

  My credit knocker knocked once ten let go and the displays were rolling 6s and 9s while making an alarm type sound??   Couldnt coin up a game but when i it the test switch it goes into test mode all displays test all lamps test but only the cabinet coils work im assuming a dud fuse for the playfield coils

[beaky]

 transistor Q15 on the interface board (solenoid driver board) is the transistor that controls the knocker coil (the schematic is a bit hard to read, its blurry)

there is a 7407 I.C. that drives that, the schematic just lists it as 13.

Diode D2 is between the 7407 and to the base of Q15

If you cant get it working and you want to send it up I will go over that board just like i did with the mpu and power supply for you. 

[Jim Jam]

when the knocker goes off once and the score is showing 6666 and 9999 the battery is dead

[beaky]

when the knocker goes off once and the score is showing 6666 and 9999 the battery is dead

the coil is going on and staying on indicating a failed transistor, but thanks for the input  

[ddstoys]

when the knocker goes off once and the score is showing 6666 and 9999 the battery is dead

  Beauty Thanks for that figured it was only a minor fault or the tests wouldn't work.  Might try a new battery and see how I go.

[beaky]

when the knocker goes off once and the score is showing 6666 and 9999 the battery is dead

Sorry JIM JAM, I missed the post by DDSTOYS.