Firepower Displays not Working
trox...@yahoo.com
and the displays worked when I picked it up. I have read Clay's
guide, but hoping for more assistance.
I tested the power supply according to the guide, and was close to all
the readings.
3J5 pin 3: -102.1
3J5 pin 4: +102.2
3J5 pin 6: 5.09
TP4: 4.9
Turned the game on the the displays were on then I heard a pop with
smoke around the master display. I turned it on again and the
displays were off. I heard one more pop, but couldn't tell where it
came from.
Turned on the game for more measurements and game plays fine with all
the sounds. I just don't have any score displays.
Any thoughts?
Thanks,
Theron
Chris Hibler
Start by a very close physical examination of the master display
board.
Something on it "let out the smoke". Note the IC name/number and we'll
be able to guide you a bit more.
There are two versions of this board. One uses a handful of ICs. The
other one uses a lot of discrete "canister" looking transistors. Which
version do you have?
--
Chris Hibler - CARGPB #31
www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
firepower
> Theron,
>
> Start by a very close physical examination of the master display
> board.
> Something on it "let out the smoke". Note the IC name/number and we'll
> be able to guide you a bit more.
>
> There are two versions of this board. One uses a handful of ICs. The
> other one uses a lot of discrete "canister" looking transistors. Which
> version do you have?
> --
>
> On Jul 4, 3:24 pm, troxel...@yahoo.com wrote:
>
>
>
> > I'm a bit of a newbie when it comes to pinballs. Game is new to me,
> > and the displays worked when I picked it up. I have read Clay's
> > guide, but hoping for more assistance.
>
> > I tested the power supply according to the guide, and was close to all
> > the readings.
> > 3J5 pin 3: -102.1
> > 3J5 pin 4: +102.2
> > 3J5 pin 6: 5.09
> > TP4: 4.9
>
> > Turned the game on the the displays were on then I heard a pop with
> > smoke around the master display. I turned it on again and the
> > displays were off. I heard one more pop, but couldn't tell where it
> > came from.
>
> > Turned on the game for more measurements and game plays fine with all
> > the sounds. I just don't have any score displays.
>
> > Any thoughts?
>
> > Thanks,
>
> - Show quoted text -
Theron
I would start out by measuring all the resistors on the master display
board with the power off. R1-R14 are 10K ohms. Any that are not
within about 10%, I would say if not in the range of 9.6 to 10.4 K
ohms, you replace them as replacements are cheap. Those resistors get
cooked on the Master display boards but usually would cause single
segments to fail on both player 1&2 or 3&4 displays together, as they
are linked. Do this anyway, although it's not be the whole story in
your case.
There are also 5 x 3Meg ohm resistors, at R15-R19 - these are for the
cathode "keep alives" and again should be near that value. If the
3Meg resistors don't look cooked and are within spec, check that you
can see an "orange glow" in the displays when the lights in the room
are off. If so, you should look elsewhere.
If you don't see the display glow, I would check the wiring to the
connectors carefully looking for a burnt wire at pins 4J7-1 -2 and -6
on the master display. Do this with the power off, as you are dealing
with 100v and -100v DC. If you find a cooked wire, sometimes just
cutting the wire back a bit to expose clean metal and then reinserting
it firmly in the IDC connector will repair the problem, if it is just
a bad connection for one of the HV lines. Remove and reseat all the
edge connectors on the master display board and especially examine the
ones that go to the backbox. Check any inline connectorsas well..
I also recommend disconnecting all the player displays 1-4 at the
Master display. Get it working with the just the credit/match and
then with one other display attached, like player 1. Then add back
the player 2-4 displays tesing for correct function each time. Use
the "display test" on the diagnostics for this.
After the above is checked, perhaps you do have to suspect the IC
chips. Clay's guide has some tips on testing the ICs on the master
board, folllow that and post your results. I've had displays go blank
on me and it was in the wiring harness from backbox to Master display.
Best wishes and here's hoping that it isn't one of the IC chips that's
faulty. Some of those are getting harder to find.
-Richard
www.firepowerpinball.com
trox...@yahoo.com
value. The area where I saw smoke is on a trace right next to the
bottom left of the score display. There is a scorch mark. It's the
two pads straight left of IC4.
The other thing I noticed was a couple of the segments in the player 4
display looks burnt.
Theron
trox...@yahoo.com
Thanks for the post. Great information in there. I check R1-R14 and
6 of them are off. They were 11k-12k. I will get those replaced.
R15-R19 all tested fine. I'm not seeing a glow when the game is
plugged in. I checked 4J7 pins 1, 2, and 6, and all looked fine.
None of them looked burnt or anything out of place. I checked the 6
HV ic chips using Clay's guide and all of those checked fine.
Also tested pin 37 on the 40 pin interconnector and got 3.995.Vdc.
What's next?
Thanks again for all the help.
Theron
firepower
Theron
No problem trying to help you out. I've fixed a few Master displays
in my pinball life and times.
1. I don't think changing the 10K resistors willl fix your problem,
but a god thing to do and def, use higher wattage resistors - 1/2W
minimum. 0.6W (or higher if you can get them to fit nicely),
sometimes you can find better heat resistance these days in flameproof
types which are actually smaller thanthe old ones, but have a better
Wattage (power/heat dissipation). You don'f need to go overboard,
I've used 0.6W with a metal body quite happily.
2. If the game plays and you get ball handling and sounds, but no
display - then it's not the blanking circuit. That would stop all
solenoids,lights and sounds as well as the displays - so you can
forget pin 37 of the interconnect.
3. DO you have the HV getting all the way to the master display on
4J7? You need to find both +100v and -100v and +5v logic with respect
to the ground there from the PSU there for it to work. So far you
said they were on 3J5, which is leaving the PSU (#3, the powerboard).
The assembly diagram from fppb.com shows the pin outs in the upper LH
corner. Link given below. Again, be very careful measuring with the
power on, but it's got to be done.
4. I assume you checked/replaced the Display fuse on the PSU at F1?
Use 1/4A (250mA) Slow Blow (or T for Timed) Fuse an * don't * be
tempted to increase the value as you actually will do more harm than
good. That would also keep displays dark, but other things will
work. If you still get +/-100v at 3J5 with the master display
disconnected says this fuse is good. If you get issues, you need to
go back to see if this fuse has blown!
5. As Chris asked earlier, does your version have tons of transistors
and a couple ICs or just 11 IC chips and NO transistors?
I ask becuase of where you said the some came from. ON my boards, IC
4 is on RH side of the Credit/Match Display glass.
Pinning this down could help figure out what IC chip got smoked, the
one that's likely to be the problem.
6. One more real possibility is that the credit/ match glass (or IC4)
is shorted internally. That's why I suggested taking the other
displays out of the picture. The only way to remove that display
without acutally taking it off (which I wouldn't do) is to desolder
R15 and remove that or leave a leg sticking out of the PCB. That's
the cathode "keep alive" -100v to that display. You can also remove
the +100v to IC4, but that means delodering Pin 10. I would remove
that entire chip and socket it, as it only fires the credit / match
display and be stopping all the other displays from working !
Sorry if this reply is a bit basic, but I don;t know all the steps you
took and have to figure that you haven't tried everything. Final
tip:
7. You can remove the fuse at F1 and once you haven't got HV there,
you can do TTL testing (+5v logic) with a logic probe on the Master
Display board, or a DMM. Check your strobe line connections from the
CPU documented inthe display harness. You can check also continuity
there with a DMM and the power off.
Schematics for the PSU is here: www.firepower.2ya.com/system6ps.pdf
Diagrams for the Master Display are here (in case you haven't found
them):
Display Harness - www.firepower.2ya.com/extras/FP-display-wiring-sys6.pdf
Master Display D8000 - www.firepowerpinball.com/downloads/MasterDisplayBoard.pdf
A replacement for some of the HV chips can be had from GPE
www.greatplainselectronics.com but you would hav to replace zener on
the PSU to lower the display voltage from 100v -it's not a bad idea.
I usually drop the voltage leaving the PSU to 90v (or so) with 2 x
1n4763a 91v zener, at Z2 /Z4. Saves all the displays life by not
overdriving them, and makes for less stress on the PSU and backbox
components. You won't notice that the displays are any different.
8. If you can't get your display board up and running, another easy
option is to buy a replacement master display board. There were
almost 17,500 Firepower games made, 19,500 Flash and 14,000 Gorgar. A
working board can't be hard to find for a few $ maybe $80 or so?
Another idea: I have bought a system 7 display board for parts (if
cheaper) to fix my sys 4-6 displays. WMS used the same IC chips and a
repro has already been done of that board using transistors, but you
need to narrow it down to one of the ICs first. Some logic chips can
just be bought from electronic suppliers. 14543, 14069. I would avoid
buying individual UDN chips, faulty and asian fakes mostly, I hear.
Buying a complete WMS board is now the best bet to get working chips.
Best wishes on fixing your Firepower, a great game! Hope I haven't
given you information overload.
-Richard
Chris Hibler
Theron, if you can snap a decent resolution picture of your board and
post it, that might help. If you can't post it, send it to me and I'll
post it. You are in good hands with Richard. His knowledge and
documentation of these systems is top-notch.
trox...@yahoo.com
through it this afternoon. Here are a couple of pictures of the
master display. I circled the spot that has the burnt marks. Some of
the resistors when replaced on the back were scorched and pads lifted,
but I check continuity and they were fine.
I took a couple pictures of the displays. Hope the link works.
http://www.flickr.com/photos/40122508@N07/sets/72157620860564613/
Thanks again for all the help. I really appreciate it.
Theron
trox...@yahoo.com
trox...@yahoo.com
high, and the burnt pad in the picture goes back to the pin 2 (+100).
Pin 1: -100.5 Vdc
Pin 2: +128.3 Vdc
Pin 3: +5.09 Vdc
Pin 6: -100.5 Vdc
I double checked the voltage at the power supply and am now getting
+131. Would I have a swing of 30 Volts if my master display isn't
plugged in? Looks like I need to rebuild the +/-100 HV section of the
power supply. Is this the correct approach?
Theron
Chris Hibler
Yes...the first thing to do is to fix that positive DC voltage.
The lower burn mark pictured is in the +100 VDC circuit to IC4 (a
UDN-6184)
The upper burn mark is to a solder pad that isn't connected. I'm not
sure how that one got there.
--
Chris Hibler - CARGPB #31
www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
firepower
> Theron,
>
> Yes...the first thing to do is to fix that positive DC voltage.
> The lower burn mark pictured is in the +100 VDC circuit to IC4 (a
> UDN-6184)
> The upper burn mark is to a solder pad that isn't connected. I'm not
> sure how that one got there.
> --
>
>
>
> > Pin 1: -100.5 Vdc
> > Pin 2: +128.3 Vdc
> > Pin 3: +5.09 Vdc
> > Pin 6: -100.5 Vdc
>
> > I double checked the voltage at the power supply and am now getting
> > +131. Would I have a swing of 30 Volts if my master display isn't
> > plugged in? Looks like I need to rebuild the +/-100 HV section of the
> > power supply. Is this the correct approach?
>
>
> - Show quoted text -
Theron
I'd echo what Chris said - he is spot on. Yes, you DO have to rebuild
+/-100v of the PSU, correct route from exterience is to rebuild the
whole HV section at once. You may get it back to spec. replacing
some of the components, but other components will have been stressed
and it may go out of whack again.
I have seen them run a bit high without a load, but not 130v+ !
Minimum you can get away with is the shopping list below (please see
PSU schematic posted). I don't think Jack sells these kits anymore, I
ripped the parts list from GPE with very few changes. So my apologies,
but it saved work:
2 of 1N4730A -- Zener Diode, 3.9V - ZR1 and ZR3 (replaces 1n5990)
2 of 1N4763A -- Zener Diode, 91V - ZR2 and ZR4
2 of 1N4764A -- Zener Diode, 100V -- Alternate for ZR2 and ZR4 (See
Notes below)
2 of 1N4004 -- 400V, 1Amp Rectifier - D3 and D4 (buy lots of these as
they can be used in the switch matrix and on solenoids).
1 of 2N5401 -- Transistor, PNP (MPSD52 Alternate) - Q2
1 of 2N5551 -- Transistor, NPN (MPSD02 Alternate) - Q4
2 of R39K -- Resistor, 39K ohm, 2 watt (Alternate for 39K 1/2 watt and
39K 1 watt) - R1 and R4
2 of R1.2K -- Resistor, 1.2K ohm, 1/2 watt (Alternate for 680, 1/2
watt) - R2 and R5
2 of R330K -- Resistor, 330K ohm, 1/2 watt - R3 and R6
2 of 100uF-160V -- Axial electrolytic capacitor, 100uF, 160 volt -- C7
and C11 for Systems 3 through 6
2 of 0.1uF-500V -- Ceramic disc capacitor, 0.1uF, 500 volt -- C8 and
C12 for Systems 3 through 6
You may get away without having to replace these, the other
transistors are cheap and redily available
1 of MJE15030 -- Transistor, NPN - Q1 (SDS-201 Alternate, You have to
cross legs over, a PITA to replace)
1 of MJE15031 -- Transistor, NPN - Q3 (SDS-202 Alternate, You have to
cross legs over, a PITA to replace)
As I said before, while you are rebuilding the PSU HV, do replace the
1n4764 Zeners with 1n4763's to reduce display voltage slightly, if the
displays are too dim or strobe- which they shouldn't if good... go
ahead and put the 1n4764's back in.
Hmmm... on to why it happened. those pads are exactly the ones I was
looking at yesterday from your description.
Top pad goes to +100v at Pin 2 of 4J7. The master display board was
designed to take two segment drivers. The UDN6184 which was common,
and the Dionics-512 which is rare. I have owned the discrete
transistor version, but I have never seen a DI-0512 IC on these
boards. Maybe someone out there has,
Anyway this top pad was used if the board had a DI-0512 segment driver
ICs installed in the 22pin DIP positions, with +100v DC at pin 22. In
which case R1-R14 were 15K (not 10K) and there was no need to cut the
trace above IC11 and add zener ZR1.
From the PICs It looks like the top pad arced badly to the ground
trace running around it. Other than that the board looks OK, the back
is fairly clean.
The machine wasn't damp or humid when thios happened, was it? Anyway,
that doesn't fix your displays so...
FIxing the D8000 master display board:
First I would get a glass fiber pen and clean up the carbon and flux
residue on the back resistors with some flux removal spray. Then I
would cut the un-needed trace between the edge of the display and the
offending pad that arced, so there is't any power directly from 4J&-2
near the ground. I have tested this on the same board in my Flash
(79) and the display board will still work to all dispalys. This
would be a good precaution, as the problem shouldn't happen again.
Sometimes carbon leaves a path to make a connection so clean it up,
and cut that trace! Carbon is what resistors are (were) made from.
The bottom pad looks clean and also goes to the +90v (or so) on the
other side of Zener Z1 which is actually used by your 6184 chips. So
now we know what happened - in effect 4J7-pin2 grounded at that pad.
So lastly I would also buy a 1n4740a Zener diode andreplace that on
the Master display board. Looks like may have done some good, but may
be the problem now as it sits between those two pads. For the price
of a zener, I'd just order it and replace.
Best of luck, and I hope this fixes your game. Firepower Rocks!
-Richard
firepower
> From the PICs It looks like the top pad arced badly to the ground
> trace running around it. Other than that the board looks OK, the back
> is fairly clean.
> The machine wasn't damp or humid when thios happened, was it? Anyway,
> that doesn't fix your displays so...
>
> FIxing the D8000 master display board:
> First I would get a glass fiber pen and clean up the carbon and flux
> residue on the back resistors with some flux removal spray. Then I
> would cut the un-needed trace between the edge of the display and the
> offending pad that arced, so there is't any power directly from 4J&-2
> near the ground. I have tested this on the same board in my Flash
> (79) and the display board will still work to all dispalys. This
> would be a good precaution, as the problem shouldn't happen again.
> Sometimes carbon leaves a path to make a connection so clean it up,
> and cut that trace! Carbon is what resistors are (were) made from.
>
> The bottom pad looks clean and also goes to the +90v (or so) on the
> other side of Zener Z1 which is actually used by your 6184 chips. So
> now we know what happened - in effect 4J7-pin2 grounded at that pad.
>
> So lastly I would also buy a 1n4740a Zener diode andreplace that on
> the Master display board. Looks like may have done some good, but may
> be the problem now as it sits between those two pads. For the price
> of a zener, I'd just order it and replace.
>
> Best of luck, and I hope this fixes your game. Firepower Rocks!
>
>
> - Show quoted text -
Reading my reply again, I meant to say:
"Carefully clean up the carbon around the ground trace and top pad on
the front, as well as the flux from soldering the resistors at the
back of the board."
Also, it should read:
"So now we know what happened - in effect 4J7-pin2 has grounded at the
TOP pad."
-Richard
trox...@yahoo.com
Thanks for all the help. I placed an order with Ed last night, and
hopefully he has everything in stock.
One question on cutting the trace. Where exactly should I do this
at? Is it possible to provide a picture? I just want to make sure
before I cut a trace.
Thanks a bunch!
Theron
firepower
Sure thing. It's a suggestion to avoid having it arc in the same
place again. You won't ever use DI-0512 Digit Driver ICs on your
board, so the trace isn't needed.
I posted a picture of my board at www.firepower.2ya.com/extras/D8000-Cut-Trace.jpg
I cut the top track's trace quite close to the edge of the display
glass. You might make a better job of it than I did, but it works
after this, as do all other player displays.
Cheers
-Richard
trox...@yahoo.com
I will let you know how everything goes in about a week or so. Just
waiting to hear back from Ed on the parts/availablility.
I keep forgetting to mention, but your website is awesome. I'm glad I
picked Firepower for my first SS game. Great documentation on the
site!
Theron
firepower
Thanks for the kind words, both Theron - and Chris. Part of what
makes this hobby great is that different folks know things and help
out in lots of ways.
I'm documenting the D8000 (IC version) display board logic diagram
just now. Seems fairly straightforward, maybe another day or so to
draw and then check it over. Just tired of looking at scans or hunting
down my original Firepower manual to look at the display board
schematic. I plan to post a link when it's finished.
I doubt I will ever bother to do a schematic for the discrete one.
Seems like not many go wrong anyway- and if they do you can just
replace a transistor or two, depending on the segment or digits
missing. Too many MPS-a92 and MPS-a42 transistors to copy and connect
up, nearly as bad as drawing the complete sys 4-7 Driver Board, which
took me weeks.
.
Let me know how you get on doing the rebuild and board repair.
-Richard