 Well, the last couple of years have been rough! Last year was the first time Fiona and I had missed out on Pinfest since we first attended in 2015. By the end of 2020, the COVID pandemic was in full swing and travelling hours away for a weekend was just not an option for us. Regardless, Pinfest 2020 still went ahead, albeit at a reduced capacity and with fewer games. I was bummed that I couldn't go to my favourite event of the year, and promised that we would be back in 2021 when the pandemic had completely blown over... Well, it's now 2021, and the pandemic has definitely not blown over. COVID is still with us. However, vaccination rates are high and things are opening up, so Pinfest is on again and Fiona and I are heading to Newcastle no matter what! It's Pinfest or bust. Like last year, Pinfest 2021 ran at a reduced capacity and with fewer games, but that didn't seem to dampen the enthusiasm for the event and pinball in general at all. COVID or not, nothing was getting in the way of us getting our pinball fix for the year! Fiona and I headed to Newcastle on the Friday. I was keen to bring a machine to Pinfest that we had not brought before. We decided to bring Demolition Man (Williams, 1994) with us; this would be the first time a Demolition Man machine had been to Pinfest. After bringing Getaway (Williams, 1992) to Pinfest in 2017 and Fish Tales (Williams, 1992) in 2018 and 2019, it felt like a good time to bring a slightly more complex game along. The week leading up to Pinfest was a busy one because Demolition Man had sat mostly unused for the last year since moving house and setting up the garage. To tell the truth, the choice to bring Demolition Man was also one of practicality. Demolition Man was the most accessible game and the one with the least known issues, which meant it would be quicker to get it up and running for the event. The first thing I had to do was fire her up and see what issues needed to be fixed straight out of the gate. Sound board issues
The game was producing some horrible static sounds whenever it was supposed to be playing music or other game sound effects. The problem seemed to affect some sounds more than others, but most of the time the intended sound was so distorted and loud that the game was difficult to play. After checking connectors and speakers, I concluded that the issue must be on the sound board, so I swapped the board into Judge Dredd (Bally, 1993), swapped the sound ROMs over, and had the exact same issue with the board in Judge Dredd. So the issue was isolated to the sound board itself.
I didn't have the time to sort this issue out before Pinfest, so I simply substitued the sound board from Judge Dredd into Demolition Man to have the game in working condition for the Pinfest weekend. Once I got back home, I had some time to dig deeper into the issue. I found that some people had documented a similar problem on Pinside. One suggested fix was some basic sound board upgrades suggested by Pinwiki which I had completed previously. Another fix suggested that the sound issues were caused by imbalanced voltages between capacitors C18 and C19. I measured voltages on my sound board and found that they were the same, and very much in good balance. To check the negative voltage across C19, place your red meter probe on the negative leg of C19 and the black meter probe on ground. To check the positive voltage across C18, place your red meter probe on the positive leg of C18, and the black meter probe on ground. A voltage of around 17v should be seen. The images below were taken with Demolition Man's sound board still in Judge Dredd.
This showed that imbalanced voltages were not the cause of my sound issues. The next thing I investigated were the sound ROMs. I had replaced the original sound ROMs with the H-6 (Profanity) ROM set and perhaps one of the ROMs had become corrupted. However, I checked all of the ROM images again in my ROM burner and they all checked out OK. Next step was to... Ball launch issues
When the ball is launched, it is sent up the shooter lane, onto a stainless steel ramp, falls onto the playfield near the pop bumpers, and then flies around the orbit lane around the rear of the pop bumpers and the rear of the centre ramp shot. From there is rolls down the left orbit shot to the upper flipper to set up a side ramp shot.
That is what is supposed to happen. The problem was that this wasn't happening very consistently on Demolition Man anymore. Instead, the ball would fall off the steel ramp onto the playfield, hit a post near the pop bumpers, and then lose speed. About 50% of the time, it would not have enough power to pass through the orbit, and would fall into the pop bumper area instead. I captured some slow motion footage which showed that the ball was listing towards the left as soon as it dropped off the steel ramp, as if the machine was tilted way too far to the left.
First things first, I made sure the game was 100% level latitudinally (from left to right). It was, yet the ball was still leaning leftwards. For good measure, I serviced the ball launch coil assembly with a new coil sleeve and made sure everything on the assembly was secure. This improved the success rate a little bit, but not much. So, the simplest solution was simply to shift things so that the ball would list rightwards instead. There's not much to adjust in the shooter lane, as the channel in the shooter lane naturally centres the ball in the lane. However, the ball is then sent onto a stainless steel ramp before it drops onto the playfield. This is the only part of the launch path that can be adjusted. The ramp attaches with two wood screws on its left side. You'll have to remove the plastic in this area to access the screws. Once the ramp was out, I slid a washer under each screw before reinstalling the ramp. This lifted the left side of the ramp just enough that the ball would no longer sway to one side when launched. 
Installation of washers under ramp screws.
Handle button not working consistently
This issue had cropped up a little while ago, but was not a major one so I had left dealing with it until I had to. Until now, that is! The round thumb button on the top of the left trigger handle had a habit of getting stuck in the down position. This didn't really affect gameplay much, as the button on top of the right handle is the one that is used for interacting with the game. The left side button is only necessary to trigger secret jackpots. However, a faulty left button causes one annoying problem: if the button is stuck down, the game will play without issue but you will not be able to enter your high score initials after game over, as this button is used to confirm each letter selection. So all that effort you spent destroying the last grand champion's high score will be completely wasted when you can't even enter your own initials. Very frustrating.
The first step was to disassemble the handle assembly to get to the thumb button switch sub-assembly. This is a regular microswitch positioned below a red plastic button, which can be depressed and is pushed back upwards by the spring action of the microswitch mechanism itself. But, as you can see in the photo below, the button was very firmly stuck in the down position. 
Stuck thumb button assembly from the left handle.
Removal of the red button from the housing was tricky. It was gummed up with dirt and grease and wouldn't budge. I had to place it in a vice, and then mallet the button out of the housing with a bit of force. Be careful at this point, because the buttons are difficult to replace, so you don't want to shatter one. The buttons are flanged so that they can only be pushed downwards out of the assembly. Don't try and smash them upwards, or they'll break! 
Button removed from the housing assembly.
Once the button was out, it was necessary to clean the button itself as well as the housing. This wasn't quite enough to allow the button to move freely, as it still bound a little bit. I resorted to sanding down the surface of the button as well as the inside wall of the housing. Using some fine grit (400 or 600) sandpaper allowed me to clear just enough material to allow the button to move freely within the housing. 
Sanding the interior wall of the button housing with sandpaper around a pencil.
Don't go nuts with the sandpaper, as you only need to clear the hole and button of debris and any grease which causes them to bind together - this material shouldn't take long to sand through. Once that was done, the button moved nicely through the housing and returned to the upright position through the force of the microswitch mechanism alone. And with that, it was fixed! Once those issues were fixed, everything was good to go! So we loaded her up in the ute and strapped her in.  Play testing to make sure everything is working as it should. In 2019, I'd just bought a Holden Commodore ute, which worked great for moving Fish Tales (Williams, 1992) to Pinfest that year. I had to cover it with a tarpaulin because the tonneau cover wasn't completely weatherproof. After Pinfest, I bought a canopy and fitted it to the tray, which provided good protection from the elements while moving machines around. It rained a little on our way up to Newcastle, so the canopy is definitely worth it for these long road trips. We drove up on Friday, set ourselves up, and got ready for the mayhem of the weekend!  Play testing on Friday night. Photo: Newcastle Pinball Association. This year was a different type of Pinfest to the normal free-for-all Saturday and Sunday sessions. Due to Covid restrictions, we only had half the number of machines we normally do, and machines were spaced out in order to keep people socially distanced. Fewer tickets were sold as well, meaning that sessions were less crowded. While it was a shame not to have the rooms as packed with machines as they normally are, it was the best we could do. Plus, it was actually quite nice for members of the public to have little to no queues to play the machines, compared to the several person deep queues there normally are. Saturday morning rolled around and all the machines started to get flipping.  Demolition Man getting a workout on Saturday morning. Saturday consisted of three sessions. There was one issue that cropped up with the left flipper during the Saturday morning session which needed attention. Weak left flipper
When testing this issue, I discovered that about 75% of the time, pressing the left flipper button would make the flipper perform a very weak flip, which was hardly enough power to send the ball halfway up the playfield.
Interestingly, there was no issue at all when the left flipper button in the trigger handle was used. This gave the flipper a nice, strong flip every time. So, the issue was narrowed down to the cabinet flipper switch. 
Trigger handles worked without issue, but the cabinet flipper buttons below did not! Photo: Newcastle Pinball Association.
In switch test, the cabinet switch behaved abnormally. When pressed, it would flicker on and off rapidly, opening and closing the switch many times a second. This was the cause of the issue - a switch closure followed by a rapid reopening would cause a weak flip due to a strong power pulse being sent to the flipper followed by a weak hold pulse. I inspected the flipper opto board and found no issues with it. I tried reconnecting the IDC connectors which connected to the opto board, (daisy-chained through a Z-connector for the handle switches), but that did nothing. Wiggling the connectors around also did not change the behaviour, so I eliminated the connectors or wiring as a possible cause. The next component was the flipper opto board itself. I cleaned the optos with a cotton bud as dust and debris can cause them to work intermittently. No luck. To narrow down the issue further, I swapped the left and right flipper opto boards. With this, the issue went away and the cabinet flipper buttons worked properly. This was another clue, as the only difference between the left and right opto boards is that the left side operates the upper and lower flippers, whereas only a single lower flipper is present on the right side. This suggested to me that the issue was with the opto used for the upper left flipper. Either way, the opto board needed to be replaced, but worked perfectly acceptably when installed on the other side of the cabinet. So we were good to go for the next session. 
Enacting repairs to the flipper switches. Photo: Newcastle Pinball Association.
With the flipper issue fixed, Demolition Man worked without issue for the rest of Saturday. Hooray!
I noticed one issue late on Saturday night after the public sessions were over. Saturday evening was free play time for all of the Pinfest contributors, so everyone was walking around, talking, and playing each other's machines. Demolition Man was working fine at the end of the last Saturday session, but as I walked past it a few hours later that night, I noticed that some of the general illumination lamps were out. Some general illumination lamps not working
On closer inspection the affected general illumination lamps were those in the upper left of the playfield. These were all on their own circuit (GI circuit no. 3, white/yellow wire). Looking in the manual, I determined that these GI lamps were all fused by F108. This fuse had blown. Simply assuming that this might have been a fluke, I replaced the fuse and turned the machine back on, but the fuse blew again. There didn't seem to be any issue with the power driver board itself, so it was time to do some more detailed inspection of the playfield.
Inspecting the lamp sockets under the playfield. Photo: Newcastle Pinball Association.
There didn't appear to be an issue with the lamps on the topside of the playfield. They all seemed intact and there was no foreign matter or debris affecting any of them. So, we moved under the playfield and started checking for broken wires, shorted sockets, or anything else which could cause the fuse to blow. We noted that a few of the lamp sockets were loose. Just to be thorough, we removed each of the lamp sockets which were on the yellow GI string, checked the LED was secure in the socket, and then reinstalled the socket, making sure it was screwed tightly to the playfield. We didn't notice anything amiss during the inspection, but when we installed a new fuse into F108 and turned the game on, the upper playfield GI lit up and stayed that way. So, whatever the issue was, we had fixed it. I think the most likely explanation is that a fast moving ball had struck the LED behind the rubber ring under the left ramp. This area gets balls flung into it at high speed from the upper left flipper, and because the LED is close to the rubber ring, it's entirely possible for it to get hit by a fast ball. Maybe this somehow caused a temporary short or other issue which was only rectified when we removed the socket and reinstalled it. Either way, the fuse remained intact for the rest of the weekend, so the issue was solved. Bit of a head scratcher, but the main this was it got fixed in time for the public to play throughout Sunday. 
LED close to the upper rebound rubber which can be struck by the ball.
Thankfully, most of Sunday went by without any issues. Demolition Man played flawlessly throughout the rest of the weekend! It was great to see people enjoying Demolition Man again, and some for the first time ever. One interesting thing I noticed related to the handles on the side of the cabinet. About 50% of the people who walked up to the machine immediately grabbed the handles, and understood how to use the triggers to flip. The other 50% never went anywhere near the handles. They went straight for the standard flipper buttons, and avoided interacting with the handles at all. Almost as if they were scared of them! The funny thing was that every kid under the age of 12 immediately grabbed the handles and understood how to use them to play. It was only some of the adults that stuck to the traditional buttons. To each their own I guess, but those people using only the cabinet flipper buttons were missing out on extra scores! For each combo you make on Demolition Man with the trigger handles, you earn 1 million points in bonus. This can stack up quickly with a few multipliers!
Of course, Demolition Man wasn't the only machine that needed a hand over the course of the weekend. Fiona and I had brought enough spare parts to Pinfest that they probably weighed as much as Demolition Man did! These came in handy on a couple of occasions. A fork switch (part no. A-11658-1) broke on Fish Tales (Williams, 1992) which told the game there was a ball in the Caster's Club (lock) area). Luckily I had a spare to get the game going again! There were some issues with Judge Dredd (Williams, 1993) which included a loss of game memory. This was because the battery holder had corrosion on it from previously leaking batteries. I installed a new battery holder, and all was well again. Judge Dredd also blew F104 (fuse for solenoids #9-16) a number of times, however we weren't able to narrow down the cause of this issue on the day.
There were other machines that had issues, of course, but thankfully all of the volunteers were able to pitch in and get things going! Before long, the weekend was over, and another Pinfest was done! These events seem to go way too quickly, even when you're mostly sitting on the sidelines watching other people play and chatting to other pinheads! As I always try to, I kept track of the game audits over the course of the weekend. Unfortunately, I forgot to note the audits before the first session on Saturday. So, the games that were played on Saturday morning were not counted in the records. However, the next two sessions on Saturday, and both Sunday sessions, were counted.
Unsurprisingly, figures are way down compared to pre-pandemic years (between 300 to 500 games started and typically over 15,000 flipper flips in previous years). However, this was expected given the reduced capacity of the event. The other thing the data shows is that I had the tilt set way too tight! 46 tilts is far too many unless everyone playing is a heavy-handed slapper. Below are this year's stats when compared to all previous years we have brought a game to Pinfest.
And so another year of Pinfest came to a close. It was an uneventful pack-up and trip back home. Fiona and I stayed an extra night at Club Macquarie just so we didn't have to rush home on Sunday night. A good opportunity to relax after a busy weekend! We can't wait for next year! Many thanks to David Hamilton for some of the great photos taken over the course of the weekend. Check them all out on the Newcastle Pinball Association Facebook page.  Fiona and I in front of Demolition Man after a hard weekend of play! Photo: Newcastle Pinball Association.
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