What am I not understanding about light bulb circuitry?
mathew...@gmail.com
thing. all but one of my bulbs are working fine.
On this bulb I take the holder out and in diode mode my DMM drops to
0-ish, you know..telling me that the filament is good.
if I put my DMM on DCV I get the same voltage on the ( ) thing that
you put the holder in as I get on all the other ones.
For some reason, as soon as I put that bulb in the ( ) it stops
getting power.....
huh?
I put the bulb & holder into place and when it doesn't light up I put
the DMM on DCV again and test, and now there's no voltage going to it.
I've worked my way down from difficult problems on this machine and
deceided to start with something simple ...light bulbs.
Jeebus...if I'm not smart enough to get some freakin light bulbs
working....how am I ever gonna figure out why my stupid F7 fuse keeps
blowing!??!
oh..and also, there are a bunch of 906's that don't light up at all.
Anyone know on a BK2K if those are flashers or GI?
Thanks
Matt
bdie...@aracamerch.com
is the diode on the board that goes to that bulb good?
mathew...@gmail.com
other side? I'm too lazy and I didn't do that. STUPID STUPID.....
beaver
saying. What does '( )' mean?
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
run to connections that the bulb holder makes. They look like ( )
around the hole. so you jam the bulb holder in there and twist it, and
the ( ) is the metal that the holder makes the connections to. ya
know?
Ken
little metal contacts were actually contacting the circuit pad /
conductor, mounting pad thingy? You can lightly bend the tabs 'down'
as in closer to the contact pads to make contact.
Also, sometimes a flat or worn spot can be on those conductor pads.
Does wiggiling the socket help?
Are you measuring voltage off of the green board? Off of the
connector? I've had to reflow solder to a pin that 'looked' OK and had
voltage on the board.
Swap the bulb holder / bulb to another location. Does the problem
follow? If so, then bad socket or one that needs to be bent, if not
someting else like a worn spot or solder issue.
Again, obvious stuff, but it's the stuff that has got me in the past.
-Ken
Stewie Caines
connector comes into contact with when you insert and turn/lock in the lamp
socket on the pcb.
Stewie
"beaver" <e...@edcheung.com> wrote in message
news:1163628131....@e3g2000cwe.googlegroups.com...
Lloyd Olson
anything to do with GI.
You are smart enough, I do believe you are over thinking things a bit. Bulb
good, socket good, header pins on that green board soldered on good, diode
for that bulb good ?
Remove the board from the game, take your meter and check continuity from
the header pins to each side of the bulb. Odds are you have a break
somewhere.
LTG :)
"Allroy1975_@_yahoo.com" <mathew...@gmail.com> wrote in message
news:1163627822.7...@i42g2000cwa.googlegroups.com...
TheKorn
news:1163627822.7...@i42g2000cwa.googlegroups.com:
Kind of having a rough time translating what you mean, but here goes...
First off, 906's are ALWAYS flashers in EVERY game. There, that's the
easy one. :)
It *sounds* like you're looking at a board with three 555 bulbs that are
mounted in twist sockets. If so, then the circuit really isn't that
complicated on the board end. I'm suspecting that you have a bad solder
joint on the board that is exacerbated when you push on the board to
install the twist socket.
SOOoooo, I'd start by checking the diode in question, then re-flowing
(actually sucking the old solder out and putting in new stuff) all the
solder joints for that bulb. I'd also lightly re-tin the pads that the
555 socket touches since I was there.
If *that* doesn't do it, I'd start looking at the IDC connector for that
board. (happens, just less frequently.)
--
Have a home video that's trapped on your camera? Want to share it on the
web or on DVD?
PinAffliction
Allroy1975_@_yahoo.com wrote:
> Okay on my BK2K there's a green board that holds the light bulb holder
> thing. all but one of my bulbs are working fine.
>
> On this bulb I take the holder out and in diode mode my DMM drops to
> 0-ish, you know..telling me that the filament is good.
>
> if I put my DMM on DCV I get the same voltage on the ( ) thing that
> you put the holder in as I get on all the other ones.
>
> For some reason, as soon as I put that bulb in the ( ) it stops
> getting power.....
>
> huh?
>
Greetings,
I believe what you are seeing here is the leakage voltage when the lamp
is out of the circuit. DMM's require tiny amounts of current to provide
a reading, so an extremely high resistance leakage reading would show
up with no load, but when you place a load ( the bulb) in to the
circuit, the high impedance leakage voltage is essentially gone. It's
like putting a 1 megohm resistor in series with a 100 ohm resistor and
connecting a battery. With the 100 ohm resistor disconnected you will
see the battery voltage, but connect the 100 ohm resistor and all the
voltage is dropped accross the 1 meg resistor. This leakage voltage is
present all over the switch matrix, the only time the lamp actually
light is when there is a low resistance path from B+ through that lamp
to ground, which is controlled by the cpu and is a multiplexed or duty
cycled process. The fact that it is not a single voltage source with a
single load complicates what you are seeing.
Regards,
Scott
mathew...@gmail.com
the entire board. it was filthy. I took out all all the bulb holders
and made them all pinch a little tighter by bending in the metal tabs.
I cleaned off the whole board. I noticed there was another lamp in the
middle of the board that wasn't working. It had a loose pin where the
wiring harness plugged in, so I reflowed some new solder over ALL of
the pins. Then verified everything from the pin to the bulb.
Everything tested fine. When I put it all back in the machine it all
came up. So..not sure exactly what the problem was, but just gave it
some TLC and spent a little bit of time on it (maybe half hour or so..)
and it paid off.
So now I'm ready to get my confidence shattered again. Gotta try to
decide if I should take on this stupid F7 blowing or my top row of
score displays displaying ...for example...a 3 like this:
_ _
_ |
_ _|
if that makes sense. so..the right part of the middle is missing all
the way across the board.
any ideas? I need to start researching that. Marvin3m says it might
one of those bios chips on the display board, but..the test (the way I
read it) says to put one lead on the ground and touch all the pins, if
any of the pins test different, it's a bad chip. All my pins test
different on all my chips..so I'm doing something wrong...DOH!
seymour...@excite.com
> So now I'm ready to get my confidence shattered again. Gotta try to
> decide if I should take on this stupid F7 blowing or my top row of
> score displays displaying ...for example...a 3 like this:
>
> _ _
> _ |
> _ _|
>
> if that makes sense. so..the right part of the middle is missing all
> the way across the board.
>
> any ideas? I need to start researching that. Marvin3m says it might
> one of those bios chips on the display board, but..the test (the way I
> read it) says to put one lead on the ground and touch all the pins, if
> any of the pins test different, it's a bad chip. All my pins test
> different on all my chips..so I'm doing something wrong...DOH!
It's common on system 11 boards to have a broken trace causing this -
buzz out all the traces from the display 6821 PIA to the connector for
the display segments, they all go under the battery holder, a prime
corrosion zone if the board has ever had corrosion. Your chips are
probably ok on the display board itself.
-scott CARGPB#29
beaver
mean that the CPU controls each segment directly (the data is not sent
in BCD form to the display board like in the numeric displays of older
Sys 11). The segment that is out is known as segment 'j'.
http://www.robotroom.com/AlphanumericDisplaySchematic.gif
You will need a logic probe, scope, or LED indicator (with a series
resistor). Probe on the display board pin J12 pin 12. That is the 'j;
segment input. Also probe a good segment, say J12 pin 11 (segment
'h'). If they look the same, the problem is on the display board. If
they look different, the problem is in the cable (break) or CPU board.
Check back here after that.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
car ones I'm finding on ebay?
Thanks again!
beaver
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=149930
Mine was from Frye's.
No doubt someone will suggest an LED with a series resistor, but this
will be a low duty cycle signal, so it will be very dim. If you are
going to test boards, you are going to need some equipment.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
http://www.tucker.com/java/jsp/cust_prod_search_results.jsp?keyword=LP10A
I just picked it up at my local electronics shop for $10.
so...hopefully I'll get a "yes it will" or "no it won't" before I go
home so I can keep/return it. :)
Thanks again.
beaver
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
no flippin clue how to use this logic probe.
I googled it a bit, I don't suppose you'd be willing to give me a quick
walk through?
nuggy
Allroy1975_@_yahoo.com wrote:
> Holy jeebers Edward....you know what I noticed when I got home? I have
> no flippin clue how to use this logic probe.
>
beaver
lead to ground, red clip lead to +5. Then touch the metal tip of the
probe to the test point.
Board repair and diagnosis takes lots of experience and/or education.
You need to decide if you are up to it.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
of this page:
http://www.pinballnews.com/shows/circus2006/index.html
reading it a few times now. :)
hopefully I can LEARN.
mathew...@gmail.com
anything...I'm gonna bouce a few things off you guys. Hopefull you can
help.
Ed, in one of your previous posts you pointed out that at
http://www.robotroom.com/AlphanumericDisplaySchematic.gif the segment
I'm having a problem with is clearly lableled "J" and that I should
check J12 pin 12 because that's the J. However in the 18mb BK2K manual
at ipdb.org:
http://www.ipdb.org/files/311/Williams_1989_Black_Knight_2000_Operations_Manual.pdf
on page 89 (page 85 of an actual BK2K manual) of the PDF it shows that
my bad segment is called "M" and on the next page it appears that the
schematic says that on J3 "M" actually comes in on pin 14.
Now, I am trying to learn this stuff. reading up on basic electronics
and learning how to read schematics and everything, and I'm pretty sure
I'm doing this right. Hopefully someone won't mind helping me out by
verifying this stuff. So if I was going to do it know with the
information I've got here's what I'd do with my logic probe :
I'd put my black clip on Pin1 of J3 of the Master Display 88 board
(because it's a ground pin)
I'd put my Red clip on +5vdc that I would get from (I'm really not sure
on this one) pin 6 on J7
then put my logic tip (ever so carefully because I don't want to touch
2 things...) on Pin 14 of J3.
You're obviously much better at this stuff than I am, so..I'm hoping
that the BK2K manual is just strange/different in it's calling that
segment M, but it seems consistant. J is still pin 12 like you
said...but my manual calls that segment M.
I hope that makes sense. Thanks to everyone who's taken the time to
read this and/or post a response.
Matt
beaver
> on page 89 (page 85 of an actual BK2K manual) of the PDF it shows that
> my bad segment is called "M" and on the next page it appears that the
> schematic says that on J3 "M" actually comes in on pin 14.
Yes, there is a discrepancy between the two references. Don't worry
about it. The one in the Williams manual is consistent with the
schematic. I verified this when I developed my Williams CPU tester:
http://www.edcheung.com/album/album05/pinball/cpu.htm
but forgot that the segments are defined in the manual when I wrote you
before.
> I'd put my black clip on Pin1 of J3 of the Master Display 88 board
> (because it's a ground pin)
> I'd put my Red clip on +5vdc that I would get from (I'm really not sure
> on this one) pin 6 on J7
Per my System 11 manual (Pinbot), gnd is J11 pin 1 and 5V is J11 pin 6.
It should be the same.
> then put my logic tip (ever so carefully because I don't want to touch
> 2 things...) on Pin 14 of J3.
Now visit the pins of J12 (segment inputs) and see if segment 'm'
pulses. Try all the other segments while you are at it just in case
there is a mismatch somewhere.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
mean...seriously...that thing is freakin amazing!!!!
So..obviously...I'm even more hopeless than I thought.....I keep
thinking I should be working on the board with the score glasses on it.
but there's no J11 or J12 on it. so I thought maybe you meant the
Backbox interconnect board, but.those say they go to the the flash
lamps...so I don't even know what J11 and J12 you're talking about! :(
mathew...@gmail.com
system from the BK2K
beaver wrote. The BK2K has 2 16 Alpha Numeric glasses while the Pinbot
has the 4 sets of 7 and one that's 4 Numerics.
It looks like everything comes to my board through 1 ribbon cable (IDE
Style..) and goes around the board and the glass is soldered straight
to that board.
where on the pinbot, there are 10 or so connectors on that board.
http://www.ipdb.org/images/1796/image-13.jpg
if nothing else it seems to me that there very well could be a J11 and
a J12 on your Pinbot Master Display Board, but on my BK2K one, there
are only 7. (J1-J7)
So I'm hopeing that what i said eariler was correct and someone can
verify that for me?
beaver
wondering how that worked out...
Allroy1975_@_yahoo.com wrote:
> Okay, I checked out the Pinbot...it has a totally different display
> system from the BK2K
> beaver wrote. The BK2K has 2 16 Alpha Numeric glasses while the Pinbot
> has the 4 sets of 7 and one that's 4 Numerics.
Yes, I took that into account when I wrote. From ipdb.org, I saw that
BK2K has the double row of alpha displays. So from your description, I
could tell which segment (M) was out.
> It looks like everything comes to my board through 1 ribbon cable (IDE
> Style..) and goes around the board and the glass is soldered straight
> to that board.
>
> where on the pinbot, there are 10 or so connectors on that board.
> http://www.ipdb.org/images/1796/image-13.jpg
>
> if nothing else it seems to me that there very well could be a J11 and
> a J12 on your Pinbot Master Display Board, but on my BK2K one, there
> are only 7. (J1-J7)
>
> So I'm hopeing that what i said eariler was correct and someone can
> verify that for me?
At some point I could download the BK2K manual, and troubleshoot along
with you, but my basic advice is the same. Use the logic probe to see
if the incoming M segment control line is pulsing. If it is, the
problem is on the display board, if not, the CPU has the problem.
So look up on the BK2K manual, on the IDE/ribbon cable, and probe that
segment.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
we're firing on ...some cylindars. :)
checked 14 and it's bouncing like the rest...put the meter on cmos and
pulse. It seems to be jumping around as much as any other pin. then
to verify that I'm doing it right, I went through the display test and
stopped it on the M segment. I know one is working because that
segment works fine on the bottom display.
segment M on the top is pin 14 on the ribbon cable. for the bottom one
it's pin 6. both of those pulse. I check al the other pins and none
of them pulse. so...I'm sure I did it right. then tracing the leads
on the board...I figured out that that pin runs to pin 3 on U8 (a
14049).
I then (hopefully did this right) compared the 14049 to the 14049 in
U7. with my DMM set to Ohms (2k) Put the ground on pin 8 Ground (last
on on the same row as pin 1, right?) then touched pin 1 on U8 then Pin
1 on U7. they weren't exactly the same, but they were close. U8
tested consistantly lower than the other. I checked against U9 and 10
as well. so...for example pin 3 on U8 (the one where segment m goes)
would drop to 819 but on U7,9 & 10 it dropped to 830-835. Hopefully
that's the right way to test a cmos chip.
but then I started looking over my schematics again...it looks like the
M segment comes from pin 12 on U16 & U 20. There's a resistor between
okay, by doing all this.I've learned a little more about schematics. I
need to test those resistos and if you guys could verify how to check
those chips (the 14049 and 7180A) I'd be very greatful. I'll go look
for myself, but I don't want to lose what I've typed and this laptop
can be funny.
Thanks
Matt
beaver
Allroy1975_@_yahoo.com wrote:
> checked 14 and it's bouncing like the rest...put the meter on cmos and
> pulse. It seems to be jumping around as much as any other pin. then
> to verify that I'm doing it right, I went through the display test and
> stopped it on the M segment. I know one is working because that
> segment works fine on the bottom display.
Nice job. That's the way to do it.
> segment M on the top is pin 14 on the ribbon cable. for the bottom one
> it's pin 6. both of those pulse. I check al the other pins and none
> of them pulse. so...I'm sure I did it right. then tracing the leads
> on the board...I figured out that that pin runs to pin 3 on U8 (a
> 14049).
At this point, you have eliminated the CPU board and the ribbon cable
as the problem. I downloaded the manual from ipdb.org, but it does not
include a detailed schematic of the board. Nevertheless, the chips on
this board are not commonly available, and I would instead buy a new
board on ebay. Some chips of the high voltage are common to the System
9 display board, which can be purchased for $15 when they come
occasionally.
If you want me to continue to troubleshoot with you on the board level,
I will need a schematic.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
there....it's on page 90 of the PDF. :)
beaver
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
Well, umm, the one I downloaded from ipdb.org only goes to page 70.
you got this one?
http://www.ipdb.org/files/311/Williams_1989_Black_Knight_2000_Operations_Manual.pdf
I just downloaded it again...and it's 102 pages. /shrug
beaver
still want to troubleshoot on the board level:
- U8-2. Is the pulsing present there? If not, U8 is bad. Should be
easy to replace.
- U16-7. Pulsing there? If not, trace is bad from U8, solder in new
wire, done. If yes, the 7180 is bad. These are almost impossible to
find, and you need to salvage a chip from another board.
You should not probe with your logic probe the resistor R45 as these
are high voltages (100V).
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
electronics shop. and picked up a 4049 to put on U8 (if it seems bad)
and another resistor @ R45. Soooo..I'm out 45 cents if I dont' replace
them. :)
What I want to know if is...would I blow anything up if I used aligator
cliped wire and ran the bottom M segment to the top one...just to
verify that it's not the glass. although...if it died all the way
across the board (like it did) it doesn't seem like it could be that.
is that correct?
Thanks again Ed. :)
Matt
beaver
Allroy1975_@_yahoo.com wrote:
> I've been thinking about this at work all day today. I ran out to the
> electronics shop. and picked up a 4049 to put on U8 (if it seems bad)
> and another resistor @ R45. Soooo..I'm out 45 cents if I dont' replace
> them. :)
Ok, but you will need a 4050 for U8, not a 4049 (unless I misread the
schematic).
> What I want to know if is...would I blow anything up if I used aligator
> cliped wire and ran the bottom M segment to the top one...just to
> verify that it's not the glass. although...if it died all the way
> across the board (like it did) it doesn't seem like it could be that.
The driver will need to drive two segments at the same time (both top
and bottom), and I do not know if it will do it gracefully. I would
not try that. The display could still be bad. The wire that carries
the 'M' current could have broken inside the display. This failure is
not distinuishable from a failure of the resistor or the U16 driver.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
(I mean..for my problem here) because I get Pulsing all the way through
to U16 Pin 7. :(
you say that that resistor should be getting about 100 VDC from that
7180, right? can't I test for voltage to make sure that it's working
or not working? like...what exactly is it those chips are doing and
what exactly is the Logic probe detecting? a jump in voltage I'm
pretty sure, right?
beaver
Either U16 (hard to find), R45 (easy), or the display (hard) is bad.
Also, you can eliminate a bad trace. I have only probed this interface
with a scope, so I am not sure what you would find with a meter. Don't
use the logic probe as it is not rated to handle these voltages.
In display test, compare the DVM reading between segment 'M' and a good
segment. You should be getting a negative voltage I think. If segment
'M' is dead, move towards the U16. If alive, move towards the display.
If you are lucky, perhaps R45 is open.
Edward Cheung CARGPB26
www.edcheung.com
mathew...@gmail.com
R45 and pulled it out of the board. it dropped right to 18. :( since
it's an 18ohm resistor.....
I'll still use my multimeter to check the voltage on M and a few other
segments. :(
mathew...@gmail.com
would cuase this.
I turned the machine on and went to the display test again and stopped
it on the M segment. I found my R45. Before the resistor I was
getting -90ish volts. after it I was getting about -1.5v. then I
checked R 62. Same resistor but controls the bottom M segment. On the
R62 I was (again) getting -90, but after the resistor I was getting
-55v. The resistor tested fine out of circuit..at 18ohms...but..I
dont' get it.
any ideas?
beaver
8-(.
Is it possible to unsolder the M segment wire of the display so that it
is not connected to the board? If you still get -1.5V 'after' the
resistor, there is a short on the board, but if it now pops up to -90V,
the display has a short.
Now that you are unsoldering resistors, you can also swap the two M
segments. You can do this by unsoldering R45 and R62 and wiring the
output of R45 to the bottom segment.
mathew...@gmail.com
display, on both, ran the top one to the bottom one and it worked fine.
So it's gotta be in the glass. I assume that can't be fixed?
Damn. thanks so much for troubleshooting this with me Ed. :)
If you ever need a kidney or something.... :P
Seriously, I have no idea why you helped me through all this, but I
really do feel like I learned quite about abot how the flow works on
these things. I'm gonna try to figure out why my F7 keeps blowing now
on my own and see how I do. I'll post if I have questions or results.
:)
thanks SOOO much to everyone, but especially Ed.
Matt
beaver
Please send me your blood type just in case 8-).
Happy Thanksgiving buddy.