Batman Forever vuk stuck on

Working on a data east batman Forever, had the vuk coil burn out. Replaced coil and replaced diodes, when game starts coil is stuck on. Research said to check and change transistor q43. Tested, it was off a bit, so replaced.

Still have coil on issues. Any thoughts from the experts? Thanks in advance

#2 6 years ago

LTG

Pinside member

Hopkins, MN

12y 191K 56,987 24 7

If you put a new coil and diode in and transistor was bad, it may have blown new diode and now transistor is bad again.

LTG : )

#3 6 years ago

???

pinmike

Inactive member

Have you tested the pre drive transistor that are associated to that coil?It would be located on the driver board in the backbox manual would tell you the location.It's the smaller one

#4 6 years ago

KMR

Phatchit

Pinside member

Davenport, FL

11y 73,900 1,461 9

What these guys said ^^^^

#5 6 years ago

SAM

dm73

Pinside apprentice

So q4 is on the ppb board. Q43 is on the cpu board. Testing both doesn't get any wierd readings compared to its neighbors... if I were to replace both, (q43 again) and q4, and the coil still is stuck up, what then may be the cause? I just don't want to keep replacing tips if it's something else.... thanks in advance

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#6 6 years ago

???

pinmike

Inactive member

You are dealing with three things here
1.The main transistor-the one you replaced
2.pre-drive transistor
3.the coil/diodes on that coil-the one you replaced,coils very seldom go bad unless its fried.
test all of these again to make sure they have not shorted again.Exactly what LTG mention

#7 6 years ago

SAM

dm73

Pinside apprentice

Thanks all. Q4 is being pulled and tested. Update soon.

#8 6 years ago

SAM

dm73

Pinside apprentice

Sorry for the late update. So we're going in, new pre transistor, new main transistor, new coil, new diode attached to coil. Should we check/change anything else before power on?

Does changing the diode on the switch need to happen?

Thanks in advance.
Steve

#9 6 years ago

???

pinmike

Inactive member

OP
Quoted from dm73:
Does changing the diode on the switch need to happen?

You can test the diode with mutimeter,Just remove the green wire in the middle of that switch.It slides right off

#10 6 years ago

???

pinmike

Inactive member

Set meter to diode setting
1.place black probe on banded side on diode
2.place red probe on the non banded side on diode
3.reading should be .4 through .6

4.reverse the probes on that dioide
5.reading should be zero

#11 6 years ago

SAM

dm73

Pinside apprentice

Diode was good, but will replace just to be safe. Thanks Mike, when I get back to windsor (my hometown) I owe ya

Beyond that we'll test from here. Hopefully won't blow again.

#12 6 years ago

???

pinmike

Inactive member

OP
Quoted from dm73:
Diode was good, but will replace just to be safe. Thanks Mike, when I get back to windsor (my hometown) I owe ya
Beyond that we'll test from here. Hopefully won't blow again.

Sounds good my friend...

#13 6 years ago

SAM

dm73

Pinside apprentice

Coil is kicking!

#14 6 years ago

???

pinmike

Inactive member