Back up and running

After self-inflicting damage to my Hot-Tip table, I ordered a replacement solenoid for the right flipper.

I pulled the damaged solenoid assembly...

And put the new solenoid in

Then put it back into the table and fired it up.

Everything works but no right-flipper.

Checking the circuit, the wiring is pretty simple. There is a blue wire that runs from the fuse directly to each flipper solenoid.

I checked the voltages, I had voltage at the fuse, voltage at left flipper and nothing at the right flipper.

After scanning the circuits for some kind of problem I went back to the solenoid. The solder on one of the posts did not look very good so I resoldered it.....and lo and behold, it worked!

and the light has been replaced, so the table is back in operation!!

whew

Self-inflicted wounds

Apparently, the source of my problems is.....me

The Hot Tip table has a couple of burned out lights. I thought it a bit difficult to count which ones were out in the series so I came up with the brilliant idea to leave the power on and in light-flashing-mode and open the table.

I lifted up the table but while shifting my grip I managed to set the partially extracted table down onto the metal bar.

POW

smoke curled out and the table went dead... really dead, not a light on it.

I checked the circuit breaker in the panel - it was fine. I opened the back and checked all the fuses on the power supply, they were fine. Looks like it was time to toss it into the garbage.


Before I retrieved the dolly, I started thinking about power. I have nothing lit at all and all the power supply fuses are low voltage - 5 and 28 volts. There must be a house-current fuse somewhere.

I followed the power cord into the cabinet and where it snaked around until I found another fuse, hidden back on the side of the lower cabinet. It was blown...off to the hardware store!

While looking around, I wondered if I had shorted and melted anything, I checked the wires on the solenoid that was the problem and they were ok, but then I looked at the solenoid itself.

I must have set it down harder than I thought as I gouged a divot into the windings of the solenoid....sigh, time to replace one of them as well...

and the light still isn't replaced...sigh

Cleaning the dropdown - part 3

This is turning into the part that will not live....

as documented last time I purchased a replacement solenoid and transistors, I soldered the transistors into the board, wired the solenoid up and tried it out. Nothing worked and now there is a whine, even after pulling out the transistors and solenoid...

After spending quite a bit of time looking at the solenoid board and trying things I found the problem appears to be in the sound board. At least when I pull the sound board everything starts working again.

However..... after soldering the transistors back in again...

All of the solenoids stopped working.
More checking, the fuse under the playfield is blown. And it blows every time I connect the replacement solenoid back in.

Time to find out if that was the right transistor.

The saga of the knocker - part 1

One of the interesting pieces of a pinball game is the "knocker." This is the device that makes a loud distinctive sound when you match and get a free game.

On the Star Trip, the knocker solenoid was fried. I found this some time back and had disconnected it (removed the wire) - now it was time to try and fix it.

Step 1 - removal

I pulled it out of the cabinet. It is strange looking compared to the other solenoids:

The dark band around the solenoid shows it is burned. I took everything apart. it has some unique features. There is a long plunger with a copper end on it and the plastic tube sticks out much further than any other ones I have seen.

Checking inside the tube, it looks like there is a wad of gum in there!

After checking with the experts, I found out that:

1) the "knock" sound is the plunger striking the bare side of the metal assembly
2) the "gum" is actually a severely melted plastic tube
3) I will need to replace everything but the metal

Off to order more parts!

Finally - a success!

After quite a bit of trying, I finally achieved some success!

 

Let me back up two months....

 

When I purchased the Hot Tip table, one of the solenoids was on continuously. I ran some diagnostics and even went so far as to unsolder transistors that I thought might be the problem and then test them. All the transistors tested ok so I still have no clue on why that particular problem is there.

 

However, after soldering the transistors back in, I put the boards back together and although the original solenoid still was in the same state, now the flippers would not work.

 

I pulled the boards again, double-checked that I had not shorted anything, reseated all chips, reflowed the solder on all the parts that I had touched....nothing.

 

The flippers have a very limited logic, they are not computer controlled as back then the computers were not fast enough, so the circuit for them is very simple on the schematics. Trying to figure out where the problem might be on the actual boards based on the schematics is really tough though and I have pulled the boards about a dozen times trying different things and checking ever more carefully.

 

Fast-forward to last night. I tested the fuse underneath the playfield. It should have had 28 volts on it since flippers, like all solenoids operate at 28v, but it did not, it only had about 5v......

 

.....great - some kind of voltage problem.....

 

 

......But it is really strange that it happened while I was pulling boards......

 

 

As I prepared to get out the multi-meter to start trying to follow voltages on the power-supply, I noticed a lone wire hanging inside the cabinet. It had a simple press-connector on it and was not connected to anything.

 

Was it supposed to be like that? or am I missing a connection somewhere...

 

After pulling up the playfield and looking around I found the other end of the wire, with the matching connector on it.  I connected them....

 

 

Low and behold the flippers started working!

 

Why every single other connection on the table goes through a board or a multi-wire connector and this one lone wire is all by itself I have no idea.....but at least the flippers work!

 

I have successfully made it back to the state the table was in two months ago!

Cleaning the dropdown - part 2 (disaster)

Time to own up. I have made a totally stupid mistake and have screwed up my table.

I took apart the dropdown and cleaned it. Afterwards the fuse blew.

After considerable head-scratching, I discovered two things:

1) I did not take good enough pictures. It seemed easy to take a couple shots and start taking it apart, but when it came time to put it back together the lack of pictures made it almost impossible to figure out which way the tiny lip was oriented on the sleeve or which wire went where.....I had lots of pictures but the wires were out of focus in every one.

2) after taking my best shot at putting it all back together and wiring it all back up and powering it on, I found I had put the solenoid in upside-down.

Which means it was wired backwards!

Naturally it pops the fuse. I took it apart, put it back together the right way and tried again. Still blows the fuse.

Checking the diode on the solenoid - Its fried....sigh.... so I ordered a replacement.

It finally arrived today and I eagerly soldered it in and turned the table on....it blew the fuse again!

...sigh...

So I disconnected the new parts and the table worked just fine.  I spent considerable time digging around in the parts looking for a short or something, without success. Finally I started checking voltages, I found that the wires to the cleaned dropdown assembly had 28 volts on them all the time instead of being switched.

I am pretty sure that means I have shorted out at least one transistor on one of the boards, possibly a chip.

Oh yaaa

Cleaning the dropdown - part 1

On the Star Trip pinball table, one of the dropdown targetswill not drop. When the ball hits it, it will usually not drop at all, sometimes it will slowly sink halfway or if I push it it will go down where it is supposed to. The other two work just fine so it was definitely a problem with the one unit.

I thought it might be a bad spring, not strong enough to pull it down and since the others were working this seemed a perfect project as I could compare the good ones with the bad one.

So I set about pulling the mechanism off the table and finding out what was wrong:

At first check, all looked ok. Nothing was obviously broken or bent out of shape.

After unsoldering the connections, I took it apart:

 

It wasn't until I had it all apart and moved things around that I found what I think was the problem. The spring seemed ok and was about the same tension as the other springs, but the whole mechanism was incredibly dirty!

This is the plunger that supposedly slides easily through the solenoid coil, it should be a shiny smooth polished rod:

My polishing tumbler is still on order, so I sprayed everything with engine degreaser and wiped it all down, then reassembled it.

It seemed to work smoother and I eagerly put it back on the table, soldered the leads back on and fired up the table....

Only to have the fuse blow out immediately!

I checked the solder connections, everything looks good....but now it doesn't work...sigh

(more to come)

A few problems with the Harlem Globetrotters

I have done an initial check of the Harlem Globetrotters. It is in pretty poor shape:

The box itself looks to have typical old-wood problem, corners are splintering - but at least it seem solid

The electronics don't work at all. When it is turned on a few lights come on and thats it, no sound, no movement, no nothing.

The playfield is also in pretty poor shape - in addition to the missing graphics in heavy-wear areas there are some more serious issues:

This shows a representative piece of the playfield, much of the paint/graphics are cracked on the wood.

The plastic isn't much better:

The edges are scalloped, cracks around the mounting bolts and even warped sagging pieces - did it sit in the sun or under a heat lamp?


Other problems are around the bumpers, missing and bent ones are in several places:

This one is a bit tough to see but the support pin in the center is bent inward and pushing on the plastic

Also, almost every single slot/hole in the table has a worn out spot where the ball went - this table has seen a LOT of use!


On the positive side, the backglass is in great shape!

it is virtually perfect with only the beginning of paint coming off in the corners around the scoring boxes.

So this one is going to be a lot of work.....

Success (at last)

Success at last!

After finally (2 months in!) discovering that there was another fuse - cleverly hidden by the Game Plan designers under the playfield rather than where all the other fuses were:

Only to discover it blows immediately when powered on.

Then spending all night carefully unsoldering each and every coil (and diode) and testing them all good.

Finally turning it back on (with all of the coils still unconnected) and the fuse blowing AGAIN!

I posted my results and Viperrwk calmly pointed out that there was one more coil.

Down in the cabinet, underneath the ball that rolls back and forth to prevent tipping the cabinet, there is a coil that fires when the match happens - that big "knock on wood" sound you hear when you are lucky enough to get a free play.

I located the coil and unsoldered it. It does not test as good as the others (2.8 ohm instead of 5.5 or 8)

With ALL the coils now disconnected, I put a new fuse in....crossed my fingers...and turned it on.

The fuse did NOT blow!

woohoo, real progress at last.

Of course it could be that it isn't blowing because there was now nothing at all on the circuit. So I connected three coils, crossed my fingers and tried again.

the fuse did not blow!

and, the coils worked. In diagnostic mode they fire one after another and each one I had reconnected worked just fine.

It appears I have real success. I may be able to put it back together and start playing it!

A green world

I just went to see Mad Max in the theaters yesterday. It was quite the action-packed movie!

One thing that really struck me as I walked my dog at the park was how green and beautiful everything is - the movie really showed how difficult and horrible the world would be if it is destroyed by ignorance and greed.

I am quite sure that was not the reaction the writers, producers and directors were anticipating, but it sure made me stop and appreciate just how beautiful our green world really is.