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    👨‍⚕️ Repair log: Doctor Who (Bally, 1992)

    1992 Bally Doctor Who Repair log

    Repair logs are quick summaries of workshop and on-site repairs. If your machine needs a service, 📬 Contact Us to discuss how we can help!


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    Plenty of fun repairs to get this Doctor Who running at full speed. First problem was an easy one. No action from the right flipper at all. Cabinet switch worked fine, but the coil would not fire. Took a look under the playfield and saw that the BLU/YEL wire had broken off the coil, as well as the power and hold coil windings. This wire is the 50 volt supply from the flipper board, and without it you'll never get any flipper action. This coil had a hard life as the lugs had all broken off at some point, but you can use the eyelets as a convenient solder point as well. Once the wire and windings were reattached, the flipper came back to life.


    Error reports indicated failures of some of the opto switches on the mini playfield opto bank. First step is to raise the mini playfield so you can activate the switches in test mode. And this was the first roadblock. The mini playfield would not move up or down at all! We will deal with that a bit later... but to get around this, you can unbolt the gearbox and cam assembly from underneath the mini playfield. Remove them, and you can now move the mini playfield by hand. Just don't drop it on your fingers!


    With the switches accessible, I found three out of five were unresponsive. Taking the target bank assembly off the mini playfield gives you access to the opto boards for inspection. The problem with one switch was obvious right away. Broken ORG/GRN wire on the receiver board. Soldered it back on and that switch started working again. Two more to go. These turned out to be dead transmitter optos. You can check these with your phone camera; a glow indicates they are working, no glow indicates they are not. These two were replaced, and all five switches were back in action.


    Back to the mini playfield movement issues. The gearbox was rooted. I could move the cam freely by hand, which is a bad sign. I cracked the gearbox open to get a better look. The problem was the gear attached to the main arbour. It was freewheeling on the shaft. A pretty common failure, particularly on Doctor Who. Off to my mate Darren who is a great welder. He silver soldered the gear and spline back onto the shaft. Greased the gears and rebuilt the gearbox. Back in the game, the mini playfield moves up and down really well now.


    Last issue (for now!). No sound effects or music at all. Game booted up and made two "bong" sounds. The sound board has its own processor, so the tones tell you its status. Two bongs means the 6264 RAM at U9 has failed. I've seen plenty of cases where a failed RAM will not trigger any unusual messages and will appear to boot normally. However U9 is usually the problem. I removed the chip, installed a socket, and plugged in a new one. Replaced the electrolytic caps at the same time for good measure. Sounds are all playing again!


    That's enough excitement for now! Hopefully that keeps this machine going for a very long... time!


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    ✈️ Repair log: Supersonic (Bally, 1979)

    1979 Bally Repair log Supersonic
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    ✈️ Always loved the backglass on this machine. Perfectly captures "the magic of flight" at a time when the Concorde had just entered service and the world still seemed like a big place...


    Anyway. Where were we? Few things to fix on this Supersonic. Game booted up and played OK... except for the total lack of playfield solenoids. Sure enough, playfield fuse was blown. Replaced it and powered up again. Fuse held until the very end of the boot sequence and blew again. I could tell that it was blowing the instant the drop target reset coil was firing. The coil was very crispy, and measured only 2 ohms. It should be about 10. Clearly this one was fried. Hard to find a replacement for these big drop target reset coils (24-1400). However, most of the large size coils will work. I found a 26-1900 which fit, and worked a treat. 


    A few displays were wonky. Two were missing some digits, one was flickering. Reflowing the header pins on these and replacing the six 100k ohm resistors solved these issues. But still couldn't get the last display to light a hundreds digit. No problem... here's a sneaky trick. The ball in play and credit display don't need a hundreds unit, so whack the display into that slot and nobody will ever know! 🤫


    During testing I realised some of the switches weren't registering nicely. Cleaned their contacts which certainly helped, but some were still hard to register. Took a closer look and realised that someone had cut the capacitor off every single switch on the playfield. Sigh. These are needed for the CPU to read switch closures properly, so don't cut them. Soldered them all back on and switches were all good. Someone had also cut the playfield tilt switch out of circuit too. Savages!


    Lots of lamps needed replacement/adjustment. Playfield got a good clean. Checked the backbox and noted a bit of corrosion on the CPU board, but we will deal with that another time. Sound board also needs a rebuild as some of the sounds are a bit scratchy and out of tune, so we'll do that at some point, too. But for now it plays nice and fast like it should!


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    🏋️ Repair log: The Incredible Hulk (Gottlieb, 1979)

    1979 Gottlieb Hulk Repair log
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    🏋️ Helping a Hulk learn to smash stuff again. This game wasn't booting up right. Some weird buzzing sounds, lamps turning on, and some garbage on the displays is all we got. There was some minor corrosion on the CPU. Probably not the root cause of the issue, but certainly the first port of call to get repaired. Board was stripped of bad components, neutralised, coated and repopulated.


    The J6 connector was tricky. The pads were almost completely destroyed by the battery puke, and would never make a solid connection with the original connector. In these cases I solder a 0.156" header to what is left of the pads, and lock them down with a good amount of solder. Then simply swap the connector for a typical Molex style connector with Trifurcon pins. 


    Some more groundwork... ground mods installed. Connectors repinned. Voltages all checked out OK (a miracle!). Now we got a little further into the boot process. Displays were showing zeroes now, but the boot wasn't finishing. This seemed like a slam tilt issue, which causes the CPU to hang up during boot. Simply install a jumper on the CPU board to disable the slam tilt switches; they're too finnicky on a System 1 game anyway. Once this was done we had a successful boot up!


    Gameplay was a bit wonky though. Left flipper and pop bumpers would not respond. The high current switches on these mechs were pitted and dirty. They were all filed down and cleaned, after which point they started working again.


    One last issue before I called it a day. The feature (insert) lamps were not working. Bulbs were fine. Fuse was fine. At this point I usually have to replace the rectifier on the transformer panel, but it was fine too. Since Gottlieb was still doing lots of shit with relays at this point, the next component upstream of the rectifier is the tilt relay. The switch for the lamps was WHT-GRY wires. It is an NC switch but was not making good contact. Adjusted it a little, and the lights came back to life.


    Game is working reasonably well now. Not the most exciting game of the System 1 era, but a cool licence nonetheless. 🧟


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    🃏 Repair log: Jokerz! (Williams, 1988)

    1988 Jokerz Repair log Williams

    Repair logs are quick summaries of workshop and on-site repairs. If your machine needs a service, 📬 Contact Us to discuss how we can help!


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    🃏 It's always humbling repairing a machine the same age as yourself. And some of them are in better condition than I am! How many other devices and appliances in your home are 38 years old? Not many, I'll bet!


    Anyway. A quick call out to get a Jokerz up and running again. There was nothing happening at boot up except for an "adjustment" message on the display. However, you couldn't read all of it as only the top display was working. The full message should actually read "adjustment failure" which means that the battery backup has failed. One look at the batteries showed why... they were toast! New battery holder and new batteries installed. Thankfully they had already been relocated from the CPU board at some point in the past. A great idea as it saves the CPU board from death if the batteries leak like this.


    Now onto the display. Voltages were all good and data signals all good. Took a closer look at the display to see what was going on. The display is actually made up of two separate glass panels. If you see white particulates and dark segments throughout the panel, it's a sure fire sign that it has outgassed, just like this bottom one had. New display on order.


    Gave the game a clean, changed some rubber rings, fixed a bunch of non-working lamps, and adjusted a couple of switches. Playing very well; it's a pleasure when older machines are taken care of!


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    🤖 Repair log: Transformers Limited Edition (Stern, 2011)

    2011 Repair log Stern Transformers

    Repair logs are quick summaries of workshop and on-site repairs. If your machine needs a service, 📬 Contact Us to discuss how we can help!


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    Minor service on a Transformers (Combo LE). A very popular theme but with only 500 of these LEs made, you don't see them very much!


    Slingshot rubbers were gone so they were replaced first up. Left slingshot was still not firing. Coil was working OK in test mode but the switch wasn't registering at all, so time to look at the assembly under the playfield. A broken diode on the switch was the cause.


    Next: ball hang-ups in Megatron. This is a common problem that was partially solved by code updates. Sometimes, a ball shot into the trough under Megatron won't be recognised. This trough is an odd design with only one entry and exit point, yet it must also be able to stack multiple balls for multiball. The fix here was to increase the pitch of the game a little so gravity helps the balls fall into line a little better. You can also put washers under the assembly to give it some more angle. In most cases the software should compensate by firing the trough coil weakly to "dislodge" any stuck balls. An odd mechanism design!


    The captive ball has a toy Bumblebee car in it instead of the captive ball. However the car was getting stuck halfway up the lane and would not roll down nicely. The main cause of this appeared to be the design of the car. The base has a Bumblebee design embossed into it, which creates ridges that bind on the switch actuator in this lane. Some tape over the base of the car helped smooth it out somewhat, but replacing it with a different car would be the best approach. Unfortunately I don't carry extra Bumblebees in my toolbox!


    Balls were occasionally getting stuck on the top of the left ramp. This is a poor ramp design with a huge lip on the metal ramp that doesn't quite fit into the "slot" on the plastics it joins with. I couldn't create any more space here so some Mylar over the lip was the best solution.


    Of course this is only the first Transformers machine made by Stern. They've just released another one (More than Meets the Eye). Hopefully it will be a while until I have to feature one of those on this blog!


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    🎣 Repair log: Fish Tales (Williams, 1992)

    1992 Fish Tales Repair log Williams

    Repair logs are quick summaries of workshop and on-site repairs. If your machine needs a service, 📬 Contact Us to discuss how we can help!

    

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    🎣 Who doesn't love Fish Tales? It's one of my favourite games to play, and one of my favourite to work on as well! This one started off as a service call to install new rubber rings, but turned into a bigger service to fix much more than that.


    First, a playfield teardown to get to all of the old rubbers and give everything a good clean. Plenty of broken lamps to replace while we're at it, too. This took a fair while due to the disassembly, but once it was back together it was looking much better!


    A cursory check of the backbox as the game was not retaining memory. The batteries expired in 2015, so that's no surprise! The original battery holder was still on the CPU board with a bit of corrosion on the lower terminals. Thankfully, no damage to the board itself, so a new lithium battery holder was installed.


    It was impossible to drop the volume down, or do much within the test menus, as one of the diagnostic switches wasn't working. No problem with the connectors or CPU board; the switch itself had died. Replaced it.


    Playtesting revealed a few more issues. The flap at the top of the playfield was taped in the up position. That's a weird mod! This gate is controlled by a coil which opens the gate on ball launch, and also when shooting the right orbit when long cast is lit. Otherwise it is meant to block balls so you can enter the pop bumpers from a right orbit shot. It appeared to be propped open because balls were not making it around the orbit on launch. But this was nothing to do with the gate. The balls were bouncing off the ball guide at the very top edge of the playfield, losing momentum, and falling into the LIE lanes. This was caused by the metal ball guide at the top right of the playfield. It needed bending to guide the ball properly towards the orbit lane. A very fiddly adjustment which needed multiple bends to get right.


    Next: the drop target was not working correctly. It has a secondary coil which pushes the target down to open the shot to the Caster's Club. This coil wasn't working. Taking a look at the assembly, I noticed the armature which pushes on the drop target to drop it was totally missing. Found it lying in the bottom of the cab. It needed a new extension spring and brass armature. Both were installed and the assembly was working as intended again.


    Lucky last. Balls landing in the eject hole at the top of the playfield were not coming back out. I could hear the coil trying to activate, but there was no movement at all in the assembly. I noticed the nylon link was broken. This is surely it! Nope, even with a new link it wouldn't move. I took it apart and realised the plunger was way too long; long enough that it was hitting the coil stop when at rest. Absolutely no space for movement of the plunger, and therefore no action from the mechanism. Replaced it with the correct size plunger and it came back to life.


    Back to catching fish and telling tales! 🤥