Barracora pinball restoration - Now with Picture Goodness!

[PetitMorte]

Crap.  It's not the transistor that's keeping the R drop target from firing.

Last night I replaced the TIN120 on the driver board with a TIN 102, and there's no difference in the pin's behavior.  crappitty crap crap.

(While I had the driver board out, and the soldering iron hot, I removed the old kludged-up battery holder from the CPU and put in a brand new shiny one.)

So I wandered over to marvin3m's repair guide and went thru the solenoid not behaving properly guide.

I connected a test lead to the side-rail, and touched the othe end to the NON-banded side of the coil's diode.  BAM!  The coil fired.  That verifies that the coil is good, and that it is getting power.  (touching the test lead to the banded side will cause the solenoid fuse to blow!)

Then I touched the test lead to the back-metal of the transistor I had just installed.  Again, BAM!  This verifies that the wiring from the driver board to the coil is working fine.

So that leaves me with 2 possible areas for the problem to be:

1) the pre-driver transistor, which, if I remember properly, did test OK.  (although I do have replacements for it, so I might just do that anyway just to be sure)

2) the driving 7408 chip.  Evidently I can test that with my meter in diode mode.  I don't have any of these, handy for replacement but in theory they shouldn't be too hard to find.

Not my pin, but here's an example of a blown chip, a bad pre-driver, and a blown transistor.


At the very least, this weekend I'll swap out all of the coil sleves for new ones and disassemble/clean the drop-target assemblies.  I have flipper-rebuild kits, but I probably won't have the time to do those, all things considered.

[ChadTower]

Good stuff, keep going.  Next time swap out the coil sleeves and clean stuff before doing the top of the playfield.

[PetitMorte]

Now I know!
 

[ChadTower]

I'm getting another System 7 pin on wednesday night, so we're going to be really heavy in Sys7 pins soon.

[PetitMorte]

Oooo!  Which one?

[ChadTower]

I'm probably jinxing the deal, but Black Knight.   

[PetitMorte]

Well, with all lack of jynxing, Best of luck to you!

[PetitMorte]

WAHOO!!!  The R is fixed!  Yes!

I tested all of the electronics again, and the solenoid is fine, the wiring is fine, the transistor is fine, the pre-drivers tested fine, and the driver chip tested fine too.  So I went back to Marvin3m's fix-it guide, and started reading.

Lo and behold, there's a section about weird things that occasionally work, occasionally don't work!  Pretty much what it came down to was the 40-pin connector between the CPU and the driver board. Evidently the solder on the pins gets old, and cracks, and turns into cold solder joints.

So I unsoldered and then re-soldered all of the pins on the CPU and all of the sockets on the Driver board.

ALAKAZAM!  The R starts working!  popping every time, reliably!    <dances a happy little dance>

While I had the head off, and the boards out, I added in the fuses for the solenoid and lamp matrix bridges.

Three cheers for Gorilla Glue!

I gotta say, having the pin inside the house, in the same room at the PC makes it so much easier to work on.

So I've started replacing coil sleeves, like I should have done before.  I started at the bottom of the playfield and I got about halfway through.  Both slingshots, the ball drain, and the shooter solenoids, and the 4 solenoids in the left drop-target assembly. 

Those drop-targets were pretty interesting.  I eventually unsoldered the wires holding it in, and removed the entire thing.  That let me take the whole thing apart and clean all of the bits and replace the coil sleeves.  Bolt it back in, resolder the wires and it's up and running fine.

I was thinking about replacing all of the lights under the playfield too.  Most of em have a dark film on them, making them dim at best.

So many things to do.    So many things done and working.

<dancec the happy dance again>

[ChadTower]

Eeek.  If you do it right you don't have to unsolder anything with the drop targets... nice work, though, on all of that.  That must have taken some time.

[PetitMorte]

I can see where, if the only thing you were doing was swapping out the coil sleeves, that you could unscrew the coils one at a time... but it would be a bit of a pain.  I'd hate to unbolt the whole unit and leave it hanging by the wires.  It was a lot heavier than I thought, and once I got it disconnected, I could take it into the kitchen and spread it out on the table, and clean all of the little parts with a toothbrush.

The most time-consuming part was the interboard connector.
... heat the solder, soldapult it, repeat... maybe bring out the desoldering braid to suck up the last bits from the hole... resolder... repeat x40...  move on to the driver board

Another plus, I made one of Tailgunner's $2 bezels for the RoadBlaster.  It looks fantastic, and is the last bit that I needed for that particular project.  All I have to do now is wait for it to get warm enough to paint, and then I can post the thing in BST or ebay.  No progress on getting the new Mobo/processor into the Mame machine. going from a PIII 650 to an AMD 900.  That should wipe away that last bits of lag from Monkey Puzzle Coin Exchanger.

... AND... I gave the dog a bath.

[PetitMorte]

One more sleeve swapped and mechanism cleaned...lower ball lock.  The plastic bit was also broken, and missing the little "ramp" bit that helped kick the ball out of the hole, so that part got replaced too.  This should save on the wear on the playfield too.

Time permiting, I'll disconnect, clean, and resleeve the right drop-target bank... 5-targets in that one.

I have noticed much better performance from the solenoids that I've re-sleeved.  The slinghots REALLY kick now!  Thanks Chad.

Or maybe, if I can get a whole evening to myself, I'll rebuild the flippers.  Ooooooo.....  Or maybe upgrade the MAME cab.

[ChadTower]

Yeah, replacing sleeves and cleaning out coils is MANDATORY in any shop job.  It's the bare minimum along with cleaning/waxing the playfield.

I'd also recommend cleaning all of the bulbs and the underside of the playfield inserts.  Those lights being nice and bright makes a difference.

[PetitMorte]

Couple of more sleeves replaced.  I haven't tackled the 5-target drop bank yet, but I should soon.  I got one of the bumper sleeves replaced, an in doing so, learned a valuable lesson!  It's much easier to remove the spoon/switch assembly first, and then the bumper bracket than it is to just remove the bracket and bend the hell out of the bumper's switches.  As it turns out, I had bent the switches pretty badly back when I removed the bumpers to clean them.  Now that I have them all straightened out, the bumper is quite sensitive, and kicks like mule the moment the ball touches its skirt.  Wow.

[PetitMorte]

Nothing pin-related to report today.  However, I did manage to replace the Motherboard/processor/harddrive in my MAME cab.  Upgraded from a PIII600 to an AMD 900.  Puzz Loop is now completely playable!!!  Now I have to get a spinner for it!!!  wewt!

[PetitMorte]

Hey there!

I've got some good news, and some bad news.

The good news is that I've finished replacing all of the coil sleeves and rebuilding both flippers!  The game (when it plays) plays visibly better, with all of flippers and kickers and bumpers snapping fast and powerfuly.  While I was under there, I started replacing lights and cleaning the undersides of the inserts as well.  That makes the lights sparkle nice and bright.   

I also figured out why I was having a problem with one of the drop targets not staying up.  Evidently that particular target's solenoid had a coil stop that was just a hair longer than any of the others.  It was *just* long enough to keep the drop target from fully catching so that it could stay up.  I compared the stops with the others in the drop-target assembly, and found that the proper "short" stopper was being used by the reset coil.  Once I swapped those out, everything was great.   

The bad news is that it's developed some CPU problem that makes it unplayable.   

Randomly,whether in play, or just in attract mode, it will "lock up".  If you turn it off, wait, then on again, it will come up normally, flash the high scores like normal.  After a few seconds or acting normal, all of the matrix lights and the displays will flicker quickly for a second, and then turn off.  This kills power to the flippers and solenoids as well.

I went out to Marvin3m's and followed their steps.  I pulled the F2 and F3 fuses (solenoid and lamp matrix) and started a display test... Bzzzzzrrp. the displays kicked out and the machine locks up.  So I'm pretty sure it's not any of the switches or coils that are doing this.

Just to be sure, I disconnected all of the wires from the body to the head, except for power.  I turned on the machine and hit the CPU's Self Test switch a few times.  The first few pushes got code 0... nothing is wrong.  After that, the self-test either wouldn't run, or would stay showing 0 indicating that the game had "locked up"  Also, the self test never automatically shows any numbers during the lockup.  Usually it just goes dark like everything else but the GI lights.

So the problem at this point should be isolated to the logic circuits... I've tried reseating all of the connectors, but again, no dice.  I went and checked the power at both the power supply and the CPU, and the +5 volts reads +4.98v.  I did accidentally notice that one of the blue Flipper Eproms feels pretty hot as compared to the others.
 

[ChadTower]

First suspect:  interboard connector.

[PetitMorte]

Yes.  RGP agrees with you.

Parts on the way to correct that.  new sockets for the chip0rz too.

[PetitMorte]

Again, Crap.   

I replaced the whole 40-pin interboard connector, replaced the molex power connectors to the MPU and unsoldered/resoldered the pins for them.

Same exact problem.   

The next thing I think I'll try is to replace the flipper chipset.  The one *does* get hot to the touch, and I don't think it's supposed to.

[PetitMorte]

Here is a much better pic of the drop-target solenoid stoppers.  The one on the left is the one that goes into the drop-target, the one of the right is the one that goes in the all-target reset solenoid.

Accidentally swap them and just that tiny difference gives you a drop-target that won't quite stay up all the time.

[PetitMorte]

IT LIVES!!!!   

I managed to snag a replacement CPU board on ebay for cheap.  It was from a Black Knight, but since they're both System 7 machines, it would work just fine.

In addition to being a System 7 board, it also cam eith Syste 7 Bllue Flipper Chips!

Switch the Barracora chips with the BK, insert board, and VIOLA!  A fuly functional Baracora pin!  *Sweet*

I was an hour late to work this morning, as I lost track of time playing it!!!