Re: TECH: Data East right sling not firing
- From: BarryMinnesota13 <theowlnose@xxxxxxxxx>
- Date: Wed, 22 Apr 2009 21:10:12 -0700 (PDT)
On Apr 22, 10:35 pm, Pinballed <probass...@xxxxxxxxxxxx> wrote:
On Apr 22, 4:25 pm, Pinballed <probass...@xxxxxxxxxxxx> wrote:
On Apr 22, 4:18 pm, BarryMinnesota13 <theowln...@xxxxxxxxx> wrote:
On Apr 22, 2:49 pm, Pinballed <probass...@xxxxxxxxxxxx> wrote:
On Apr 22, 3:06 pm, BarryMinnesota13 <theowln...@xxxxxxxxx> wrote:
On Apr 22, 3:45 am, Pinballed <probass...@xxxxxxxxxxxx> wrote:
On Apr 22, 4:29 am, Pinballed <probass...@xxxxxxxxxxxx> wrote:
On Apr 22, 2:45 am, BarryMinnesota13 <theowln...@xxxxxxxxx> wrote:
Without a logic probe I could only try this...pin 5 reads 4.9vdc. Pin
4 reads around 190 vdc and when I ground cn18 pin 8, pin 4 (on u12b)
drops about 10 vdc.
I wouldn't expect to see such high voltage in a logic circuit.
Perhaps your meter is auto-ranging and it was reading 190 millivolts.
Since the other switched solenoids are working when you ground their
associated pins at connector CN18, check a working circuit. Then
return to the non-working circuit.
For instance:
At Pin 2 of U12b you should see your 4.9V. This is associated with
solenoid driver 6, Q13. Then you ground pin 2 of U12b the solenoid
should fire. Then you next check pin 1, - should be low voltage,
then ground pin 2 again and you should see around 5 volts at pin 1,
when the coil fires.
When you repeat this with pins 5 and 4 on this same chip, as you did
before, it should indicate that this NOR gate for Q12 is functioning
or if it is a problem, requiring the replacement of U12B.
I don't what game you are working, but I am using the schematics from
a Data East Checkpoint. My schematics are very small, and difficult
to read. So please double check my numbers to make sure I have read
the info correctly. Also -- you didn't specify what game you are
working on so I hope the generation is OK that the logic is the same.
Barry
Ok, I'm pretty sure it should fire the right sling when I ground pin
4 (U12B) and nothing happens. All the other 4 special solenoids fire
at other certain pin points. Game is Robocop, but now I leave that out
because theres not alot of Robocop owners out there. The 7402...I
have these 74LS02's here and some 74LS00's, which seem to be a
different type of TTL. But anyways, I think I subbed a 74LS02 for a
7402 before, any opinions?
Stan- Hide quoted text -
- Show quoted text -
Heres some more info for you.
I just read at U12B each of the pins and what happens when you fire
the coil, the voltage goes down, then up very high if you leave the
coil on...now I can see why you dont want those coils stuck on for
very long. Anyhow, pin 4 which should be for the right sling, just
goes low, then back to the 4,9v. This is because the coil isnt firing
anyways at this point. So I go to fire it manually by grounding pin 8
on CN19, while reading what happens at pin 4 on U12B. This time I get
a reading but its not right! It goes low at first, then it goes into
the minus side for around 100 v (ac?) or more. So, something is
backwards. Is this at the coil? Is my coil backwards...diode
backwards? My head on backwards?
Just in case, do you have individual fuses for each special/switched
coil? and is the fuse for your sling OK?
I mixed the correct logic state that fires the 2N4401 transistor-- up
too late last night. Easy test is if you ground pin 4 of the 7402
does the solenoid now fire? Grounding pin 1 for another solenoid does
it now fire. If the solenoid does fire when your ground pin 4, but
doesn't when you ground pin 5, your 7402 chip is bad.
In the case where you ground pin 4 and the solenoid doesn't fire, your
problem lies with the Q6 2N4401 and Q12 TIP102/122. Because if you
ground the tab on Q12 the coil fires -- correct?
Barry- Hide quoted text -
- Show quoted text -
yes, it'll fire when I ground Q12 and nothing happens when I ground
pin 4 it wont fire. It'll fire on pin 5 but not the right sling, thats
for one of the other special solenoids (center pop bumper). So, I
guess Q12 or Q6 may be bad. I suspect its the traces. Maybe Q12 isnt
getting grounded properly. I may have to jumper a wire or two then.
Stan
Hello Stan,
For the 7402 at u12b, pin 5 is the input and 4 is the output, the
other coil on this chip is associated with input pin 2 and output pin
1. What coil fires when you ground pin1 or pin2? There is something
amiss with this circuit and maybe a solder splash or solder bridge or
other problem. When you are checking the board around the
transistors, I would take a close look at the underside of u12b.
Barry- Hide quoted text -
- Show quoted text -
Hi Barry,
ok, pin 2 fires the left sling, 5, 8 and 11 fire the pop
bumpers...thats what I'm getting
Stan- Hide quoted text -
- Show quoted text -
Ok, let me clean up this mess a little...
U12 A and B I got confused for a sec.
Pins 2, 5, 8 and 11 of U12A fire the left sling and the pops.
Pin 5 on U12B should fire the right sling but it doesnt when grounded.
Going back to check what the voltages are for pins 5 and 6 and see
whats up there.
Stan
Ok Stan,
Pin 5 is the input from the switch closure. Pin 4 is the output to
your Q12 through Q6.
Ground Pin4 of U12B and that should fire your sling coil.
You can check the output of the other solenoid gate on U12B -- Pin2
and that should fire
another coil. Pin 1 is the associated input. Pin 6 is not part of
the special solenoids.
Barry
.
- Follow-Ups:
- Re: TECH: Data East right sling not firing
- From: Pinballed
- Re: TECH: Data East right sling not firing
- References:
- Re: TECH: Data East right sling not firing
- From: Pinballed
- Re: TECH: Data East right sling not firing
- Prev by Date: Re: Capt. Fantastic Fuse Values
- Next by Date: Re: Seawitch Glass
- Previous by thread: Re: TECH: Data East right sling not firing
- Next by thread: Re: TECH: Data East right sling not firing
- Index(es):
Relevant Pages
|
