Arcade Crusade: Pinball Repair Check Fuses F114 and F115

The Pinball Network·video·12m 46s·analyzed·Jun 5, 2020

Analysis

claude-haiku-4-5-20251001 · $0.018

TL;DR

Whitewater F115 fuse repair: shorted target damaged U20 IC, replacement fixes error.

Summary

A detailed technical walkthrough of diagnosing and fixing a 'Check Fuses F114 and F115' error on a Whitewater pinball machine. The host explains the common causes of each fuse failure, demonstrates troubleshooting methodology using a multimeter and power isolation tests, and documents the specific repair: a shorted Bigfoot target that damaged the U20 (2803 IC) chip on the MPU, which was resoldered into a socket and replaced. The video serves as an educational resource for operators and home technicians encountering this common WPC-era issue.

Key Claims

F114 fuse failures are typically caused by bad bridge rectifiers (BR1/BR2) under the power driver board heat sink
high confidence · Host explains bridge rectifier failure as primary cause of F114 blows; references Pin Wiki documentation
F115 fuse failures can be diagnosed by pulling J210 (MPU power connector) and turning on the game; if fuse still blows, the issue is on the cabinet side (shorted switch); if it doesn't blow, the problem is on the MPU
high confidence · Host demonstrates and explains the diagnostic isolation technique in detail
The U20 (2803 IC) chip on the MPU is the first component to fail when a cabinet switch shorts to a coil, sending 70 volts to the 12-volt line
high confidence · Host explains the electrical flow path and confirms U20 was damaged in his specific case
Later WPC95 and some later WPC machines began socketing the U20 chip as a design improvement to prevent permanent damage
high confidence · Host mentions this as common practice by manufacturers like TNT/Todd Tuckey before shipping games
A Bigfoot target on the Whitewater playfield was shorted directly to an adjacent pop bumper coil, causing the fuse failure
high confidence · Host identifies and fixes the specific playfield short on his machine

Notable Quotes

“when that happens, you're basically sending 70 volts to your 12-volt line, and it's just going to shoot that right upstream”
Arcade Crusade host @ ~2:45 — Explains the electrical mechanism of how a coil-to-switch short causes fuse failure
“every time you short a switch to a coil, that's going to be the first thing that goes... U20 will be the first thing that goes”
Arcade Crusade host @ ~5:15 — Establishes U20 as the critical failure point in switch matrix shorts
“in later Williams boards, they started socketing U20 right here... I actually had to desolder that chip and put a socket in”
Arcade Crusade host @ ~6:00 — Documents design evolution: manufacturer improvement vs. retrofit repair on older boards
“This is the reason, you know, TNT, Todd Tuckey, this is the reason before they send games out, they always socket that switch matrix 2803 at U20 on the MPU”
Arcade Crusade host @ ~10:30 — References industry best practice by major operators/rebuilders
“if it's not socketed you'll need to socket it and then drop a new chip in”
Arcade Crusade host @ ~14:15 — Practical repair guidance for technicians working on machines without factory sockets

Entities

WhitewatergameArcade CrusadepersonTodd TuckeypersonThe Pinball NetworkorganizationPin WikiorganizationWilliams Pinball Computer (WPC)productU20 (2803 IC)productF114 fuseproductF115 fuseproductJ210 (power connector)product

Signals

?
community_signal: Host creates detailed educational video documenting common WPC repair procedure to help operators and technicians troubleshoot fuse failures
high · Entire video structured as step-by-step troubleshooting guide with explicit offer to help viewers: 'If you run into this issue, let me know. I'll help you out with it.'
?
product_strategy: Industry standard practice (exemplified by TNT/Todd Tuckey) of socketing U20 before shipping machines represents post-manufacturing improvement addressing design weakness
high · Host references: 'TNT, Todd Tuckey... before they send games out, they always socket that switch matrix 2803 at U20 on the MPU'
?
technology_signal: U20 chip vulnerability on early WPC boards (pre-WPC95) was a design flaw later addressed by manufacturers through socketing
high · Host notes: 'in later Williams boards, they started socketing U20... Even some of the later WPCS games, I think they started socketing it... obviously it wasn't socketed on white water'

Transcript

youtube_groq_whisper · $0.038

0:00

What's up Crusaders, welcome back to another episode of Arcade Crusade. In today's video we're just going to be diagnosing a small issue I ran into on Whitewater after I put everything back together. been playing for a few days here and I ran into the check fuses issue and I'll go ahead and turn the game on I was in the middle of going ahead and fixing this and realized I should probably shoot a quick video on it just to help some people out if they encounter it but we'll wait for the ROM to load up. So you hear the ball search kicking in right now and you see the check fuses F114 and F115 message. So I'm going to go ahead and turn this off so the ball search stops and I'll zoom in a little bit more. That should be good. And like I said, I was already in the middle of diagnosing this and when this happens, there's a couple things that can happen and I'll tell you what happened specifically to me but so this happened I grabbed my multimeter and I checked continuity to see if either of those fuses were bad so f114 over on the right side of the power driver board this bottom fuse right here that was good and if that blows most of the time the culprit are your two bridge rectifiers under this heat sink heat here, BR1 and BR2, if those go bad, they can blow F114. And there's an entire pin wiki section dedicated just to this fuse error. So if you encounter it, check there. I'll leave the link in the description of this video so you can go there. But my issue was F115 was blowing for me, and it's no longer blowing for me, and I'll tell you why. But I basically kind of rigged it so I could still get the message to show up. But what had happened, my Bigfoot target had shorted to the pop bumper coil right next to it. And when that happens, you're basically sending 70 volts to your 12-volt line, and it's just going to shoot that right upstream. And the Bigfoot's, the cabinet switch for that is on one of these green wires, so it shoots up from J206 up to U20 here. So like I said, I tested here. This fuse was bad. I put another fuse in, it blew again. So I'm like, all right, well, go from there. I found the issue under the play field. I got that sorted out, but my fuse was still blowing. So what you can do, you kind of start by checking for your 12 volts on the power driver board. And you know, I had it, but one way to know if your issue is related to a shorted switch on the play still or if you have an issue with your MPU if you pull J210 which is your power connector here on the MPU if you pull this turn the game on and it doesn blow F115 you will know that your issue blowing that fuse is related to something on this board and the first thing that's going to take a hit when that fuse blows, U20 right here, it's a 2803, this IC will take the first hit and every time you short a switch to a coil, that's going to be the first thing that goes. Same thing will happen if you short a GI bulb to ground, this will be, U20 will be the first thing that goes and that's why in later Williams boards, they started socketing U20 right here. I actually had to desolder that chip and put a socket in. So anyway, I desoldered it, put a socket in, put the board back in, and I hooked everything back up and I turned the game on with the chip out, just out of the socket, and it is not blowing F115 right now. So we know that chip is bad. Now, if I put it back in and it blows again, we could have a bad U14, which is a LS374, or one of our 339s, U16, U17, U18, U19, any of these 339s right here could be bad. And if those are bad, it could also be blowing that fuse. We have to see what damage was hit when that switch shorted to our coil. So hopefully now that the fuse isn't blowing and I only have U20 removed, when I put it in, hopefully this should turn right back on. We should have no issues. So I ordered a bunch of sockets and a bunch of these ICs just to have on hand. It's a pretty common issue to come across. And like I said, on later WPC95 games, they started socketing this chip. And even some of the later WPCS games, I think they started socketing it. obviously it wasn't socketed on white water so I had to pull the chip but right now I'm just gonna put the chip in its socket and we'll go from there all right got it in its socket it is in the correct way. This is a, I think an 18 pin IC. Like I said, it is a 2803. And if you follow the pin wiki, it basically suggests that that will be the first chip to go when this happens. So we got our new one in. We can go ahead and close this. And if we continue to have cabinet switch issues because basically that chip controls your whole switch matrix. So if we continue to have issues here, there's a chance another IC could have gotten taken out when that shorted. So we'll turn the game on right now. And let me grab the keys no ball search so that a good sign And that fuse didn blow so also a good sign

7:38

We can let that go because we didn't hit a switch. All right, we'll let that drain. All right, we'll turn it off. I'll walk you through it just one more time, and I'll take the camera off the tripod just to show you exactly what I had to do to fix this. And like I said, I'll leave the pin wiki link in the description. So if you guys, this is a pretty common issue. This is the reason, you know, TNT, Todd Tuckey, this is the reason before they send games out, they always socket that switch matrix 2803 at U20 on the MPU. you. So if you get this error, first two things you want to check fuse F114 right here. If this is bad, usually one of your two bridge rectifiers under this heat sink is bad. If you need to swap that out, you're going to need thermal compound because that heat sink has to come off those bridge rectifiers. One of them is probably shorted to ground. If that fuse is fine, you're looking at F115 right here, right next to your J113 ribbon cable. This was the fuse that was blowing for me The way to know if you have a cabinet side issue or a MPU issue is this power connector right here J210 You want to pull this completely off, turn your game on. Your game obviously won't boot because you don't have power at the MPU, but if this fuse blows, you know you have some sort of cabinet switch short somewhere that's shorting the 12 volt line to ground. If you pull this, you know you have an issue somewhere in the MPU circuitry. And if you look at the traces here, the first chips that come off of your connectors here, they go right up to U20, right on this J206, and then also to these 339s right here. So one, two, three, four, you can see right here, that's the 2803 that I socketed. but these 339s can be taken out too but this one if it's not socketed you'll need to socket it and then drop a new chip in now that we have a new chip in it's fixed and also like I said U14 right here this 374 this can get taken out this is the first chip after U20 so if it does enough damage it can go back to U14. Now these 74 ICs any IC that starts with 74 the internal circuitry can be tested with a diode test. So basically this is also on the pin wiki and I can leave a link for that. But your red lead goes on a pin one, I think, or your black lead. And basically you just go through or pin 10 maybe, and you go through and you just check to make sure that you have about 0.4 to 0.7 resistance between all these pins here with one lead staying on that same pin. And if you have continuity across any of those pins where you shouldn't have continuity, you know you have a bad IC. I tested this when I had the board out. I knew it was good. So that's good, and my issue was all U20. That was blowing my F115. Once I fixed the target so it wasn't shorting to the coil anymore, and I swapped this out, it is now fixed. So just some basic troubleshooting. I was pretty much already had it all the way fixed and I knew U20 was going to do it. But if you pull U20 out of the socket, turn your game on, you can get that check fuses error to come up. So that's why I pulled it out just to show you guys the error that I was getting and kind of what I went through to fix it. So now board's back in. Hopefully we shouldn't have that issue anymore. We can make sure that target's registering still. If it needs more adjustments, we'll mess with it just to make sure it's not too close to that coil. But yeah, I mean, it was just a quick one, and I figure I should probably document it before I fix it. So yeah, I just wanted to show you guys what I was up to, just a quick fix. If you run into this issue, let me know. I'll help you out with it. So thanks for watching, guys.