Sharkey’s shootout

This machine has been sitting in the workshop for a long time, like a patient friend waiting for its turn. And finally, it was its turn to be taken care of. The reason for being set aside was that the CPU was ruined beyond repair by battery leakage while the game was in storage. When I first got it there was no replacement CPU’s to find anywhere but a little while ago Todd at TNT mentioned in one of his videos that Stern had produced a batch of new CPU’s and K’s arcade had one to sell. It was delivered with the latest software for the game and most important, an external battery holder.

But first thing first, the reason for being put in to storage was that it broke down and smelled burnt. The problem was easy to spot at the little auxiliary transistor board at the left side in the back box. One transistor had exploded and one was shorted. These transistor controls the pop-up posts in the outlanes and the center post between the flippers. The center post coil was shorted and also one of the outlane post coils was shorted as well. I didn’t expect two coils to be shorted at the same time when feed through the same fuse.  Maybe the coil connected to the exploded transistor shorted first then a new fuse was applied and later also the second transistor and coil shorted, I do not know for sure. But it doesn’t matter, two new transistors and two new coils and this part was fine again.

 

 

Next step was to install the new CPU and fire up the machine and this didn’t go as smooth as I hoped. I got some odd text message at the display which went black after a couple of seconds and the singe drop target in the right orbit jumped up and down continuously.  Expecting the worst, faulty CPU, I started fault finding but it turned out to be not as bad as I first thought. The display problem was due to battery leakage that had dropped from the CPU down to the ribbon cable connector at the DMD driver board and the jumping drop target was due to the coil stop for the reset coil was missing. So the CPU tried to raise the target but it didn’t manage all the way up and it fell down and the reset cycle started again. I found the coil stop in the bottom of the cabinet but the threads for the screws to hold it was dammaged and I had to mount it using slightly longer screws and lock nuts.

Once these two problems were fixed the game booted properly and worked fine. The only remaining electrical problem was a blown GI fuse which was caused by a short at the back side of the cabinet light board.

Then it was time to disassemble the playfield for cleaning and new rubbers.

 

 

Once the playfield was disassembled it was carefully cleaned and it got two coats of wax while it was easy to reach all areas.  There was a couple of wear spots above the two upper pop bumpers. At the left one the wear was in a black area so I touched it up and protected the area with a mylar patch. The wear at the right bumper was in a yellow area and I do not think that I would be able to mix the paint and make it look better than what it is now so I just protected it with a mylar patch to stop it from getting worse.

 

 

 

 

All visible screws and nuts was hand polished during the reassembly process and all other parts cleaned and polished. The drop targets got new decals and the bumpers were rebuilt with new skirts and bodies. Also the flippers were rebuilt with new sleeves, links and bats.

 

 

 

 

One remaining problem at the playfield was the wear by the VUK hole. I tried to find a Cliffy protector to cover it but it was nowhere to be found. I have seen pictures of Sharkey's with protectors and some web stores lists it, so it does exist,  but none of the stores had it in stock.  Instead I touched up the wear and protected it with mylar.

 

Once reassembled it became a very nice looking playfield.

  

 

The last thing to do was cleaning the cabinet inside and out, removing the lock bar brackets at the front and give the shooter a new barrel spring. I also gave the game a matching keyring.

 

 



 

 

 

Rock-Ola 1454

This machine had a couple of interesting faults. The first problem was that it didn’t detect any selections. Once a selection was made it just run the magazine back and forth without stopping. There are several things that could cause this behavior and I made some measuring hoping for an easy fix, but not… I found an open circuit in the wire connecting to the carriage assembly.  This wire rotates round the magazine shaft following the carriage round the selector unit. It held for 60 years but now it was worn out.

I searched the internet trying to find a recommendation of a replacement wire but didn’t manage to find anything about it. Instead I found a wire at a car part retailer. This wire is not as soft and flexible as the original one and will probably not hold for another 60 years but I expect it to hold for many years to come.

When replacing the cable I made new cable clips out of metal stripes covered with shrink tubing. The old plastic clips were too brittle to be reused and the inner one was broken and had to be replaced.  

The second problem was that the magazine sometimes stopped to rotate and to get it to go again the gripper motor had to be manually turned for a couple of turns. This fault was very intermittent and has been in the machine for quite a while. A couple of years ago it also caused all records in the machine to be destroyed. What’s happening is that while the magazine motor rotates the magazine also the gripper motor rotates, very slow, causing the gripper to start closing against the records.  The records was destroyed when the inner gripper meet the records in the rotating magazine. All records looked like packman before the owner managed to cut the power to the machine. There is actually a built in protection against this type of disaster, more about that in a little while.  

 

The cause for the gripper motor to turn at the same time as the magazine motor was the interlock relay in the control box. The interlock release contact in the diagram above is actually two switches in parallel, to ensure that the gripper motor is properly shorted to ground. When checking the switch with the continuity setting it was fine but when measuring the resistance it was about 25-50 ohm. This caused a voltage drop over the switch that was enough to drive a current through the gripper motor causing it to slowly rotate. The protection mentioned above is the Safety micro switch in the diagram. This switch is located at the cam at the gripper drive shaft. The function is to cut the current to the magazine motor before the gripper reach the records. That’s what happened when the magazine stopped and the gripper motor had to be wound back to get the magazine to turn again. In this machine the Safety micro switch was misaligned and didn’t stop the magazine motor before the disaster was a fact. This fault could have been in the machine for a long time, maybe even since it was brand new. As long as everything works as it should then the Safety switch doesn’t matter, but when it goes wrong it’s worth its weight in gold.  

 

 

I visited another 1454 with an interesting problem a little while ago, related to the cable clips at the selector arm. This machine did stop the magazine slightly wrong causing the gripper to miss the records, but only at lower number selections and when the magazine was running clockwise. The cause turned out to be the outer cable clip. It was broken and at a certain point the carriage cable wedged between the arm and the solder lugs at selector unit forcing the selector arm inwards and the screw head that pushes the carriage slipped of the top where should rest causing the magazine to stop slightly wrong. A new cable clip and the machine worked fine again.