This Display Is REALLY Screwed Up! - 1987 Williams F-14 Tomcat Pinball Machine Repair 5 

Said it before, it's still true now: The world will be a sadder and dimmer place when the last of those old plasma displays finally gives up the ghost.

The legend returns to fix another pinball classic!

The '555' chip is a timer chip and is much loved by us electronics folks, the capacitor and the resistor set the timing (an R,C network) and are attached to the 'Threshold' pin, so by having that cap out by a factor of 10, the blanking timing is out by the same amount, thats roughly it anyway ! and you went straight to it, great work ! looking forward to the rest....cheers.

Before you repaired the board, the bottom displays were showing more. I can see that dim digit on the working displays is pretty badly burnt. Using the wrong cap would upset the timing as it is attached to a 555 timer, so it would change pulse timing for blanking :). I know you will get these all running

Nobody figured out the blood in pocket quote? Great job Ronnie!!! 👍👍👍

This is why we watch you Ronnie! Never know what ya gonna get! 🤣😂👍

Even I small towns never a dull moment 😂 love the entertainment keep it up.

Don't feel bad about the display- think you paid your dues fixing that CPU board! Great work!

Fantastic video again Ron well done.

Nice work Ron!!

Loved the little segway near the start with Mister MDMA outside the shop :)

I like how you go in depth with this, really, and that guy across the street was sad😢, looks like he was a tweaker, hopefully he gets help to turn his life around, once upon a time was a small family owned video arcade in Minneapolis named Thompson's and they had an f14 tomcat pinball, and I used to put around ten dollars in it weekly Playing and practicing, always lots of fun, can hardly wait to see this one playable again, Liked the vid

Even after the end of the Cold War Gen. Jagov is still so angry! Maybe he needs a hug?

From EM to solid state, you do a great job educating us. So fun! Thanks Ron.

I can't wait to see this thing back up and running. This thing was awesome when you showed the last one you worked on. "Now you die" "You're dead comrade". Makes me wish I could have played it because it's an awesome looking pinball machine

Once again, great work.

Woke up fired up RU-vid and Ron had another great upload for me to watch while drinking my coffee. Thanks Ron. Now I have to take my drivetrain apart on my personal bicycle and clean in up.

Talking to myself, Talking to myself. I am going to mumble on all night long , talking to myself. If that dude don't pump the breaks he's going to get all burned out like that pinball game your working on. Hay great videos . I'm hooked, I found your channel a few months ago and haven't missed one of your videos . I have learned so much, I want to find a older pinball game and fix it and then play the blues away. Thank for the brain candy, and keep up your amazing work.

This is the first video on this particular display on RU-vid,I just swapped mine out after 33 years for a LCD,l was playing away and suddenly heard a loud popping sound, looked up and display was gone, technician didn't want to fix it so I kinda had no other option.Yes the new one sure is pretty out of the box,and so much lighter than the original.

Vacuum fluorescent displays look cool, but they suck when they go bad, It's good to see there are LED replacements available.

It’s amazing that those led displays flicker when all the lights blink on

It's sad that the plasmas can't be fixed, but at least the LEDs look great too! And what a miracle you achieved with the PCB, man!

You sir would make a great detective

I was really hoping you could get player 1 and player 2 working. I like when you go in-depth on these videos. Great Video Ron.

28:22 if I understand this right, the circuit appears to make a time delay that is proportional to the values of R79 (33k) and C58 (1u). These make an RC series circuit that has a time constant of approximately 33k*1u = 33ms. This means that C58 will charge to about 2/3 of Vcc in a bit over 33ms from the fully discharged state. This will satisfy the NE555 pin 6 input (threshold) and keep the pin 3 output low. R80 (3,3k) and R84 (6,8k) resistors make a voltage division a wee bit over 2/3 of Vcc which is enough to keep the NE555 pin 2 input (trigger) high. When the 7404 output pin goes low, it charges C57 which will cause pin 2 to go under 1/3 of Vcc for a tiny amount of time, setting the NE555 pin 3 (output) high and pin 7 (discharge) low, and simltaneuosly it triggers Q50 to rapidly drain C58 to a wee bit over 1/3 Vcc. When C57 has charged over 1/3 Vcc, this will allow pin 2 high and Q50 will also close. Now C58 will charge through R79 and when it reaches 2/3 of Vcc it will trip the NE555 pin (threshold) which will reset the pin 3 output back to low. The charging only occurs between 1/3 and 2/3 of Vcc so it does not take the full 33ms but roughly 10 to 15ms. So every time the 7404 goes low the NE555 will produce a high pulse of roughly 10 to 15ms at pin 3 (low at pin 7) regardless of the 7404 output staying low for a bit longer or shorter. Making C58 a different size will quite proportionally affect the pulse length, I assume that at 0,1uF it would only be in the vicinity of 1 to 1,5ms as the time constant goes down to 3,3ms. It appears that with C58 being too small a value, it would not hold the blanking signal long enough that all digits can be scanned - and it appears that there is some room for variance without ill effect. Are you going to scavenge the working glasses from the old display unit?

I'm loving it, more more.. saving all your videos I'm my Playlist to go over it I ever have an issue with my F14..👍🏾👍🏾👍🏾🍹

Just built a Wolffpack for a system 11. Quite a fun build and looks great! Can't go wrong with low voltage LED displays!

Great job on troubleshooting those score displays!

Great video Ron! Had a chance to pick up a really nice one of these but was buying a different pin at the time. Never played this one but watched you play a different one that you fixed up. Looks like a really fun game.

Great video Ron, I thought I fixed the displays on my Gorgar but at the end I had to buy new display. It happens to the best of us. Keep up the good work on the machine. Have you decided what you going to do on the playfield? See you on the next video in the series.

Cool on the light bulbs working again. I guess the blanking signal was the ocsilator governing the lamp illumination pulse? Though I can't wrap my mind around how the C58 cap on the 555 (blanking) timer, could have caused the 'C' signal to be pulled high through an 7404 inverter and a decoupling cap (C57). Makes my puzzler hurt.

That cap might be one of the caps that determines the timing of the 555. If that input controls the blanking, it could be why the display is blank. I think a smaller cap may increase the frequency of the 555 output, which would cause it to pulse faster.

Enjoying all of the videos you post. Much so I bought a pinball machine to try and get my hands dirty to fix up. Still waiting for it to be delivered. The down fall of living in the middle of nowhere. Ha!! A couple questions popped in my head regarding the play field. 1. When you do the touch up paint, do you just clear coat that spot? 2. Do stickers for the art work on the field are they good to use and can they be clear coated to prevent wear? Thanks again for the great videos.

Believe it or not LED's do were out. The specification is like 50% brightness loss after 100,000 hours of operation at full current. One year of continuous operation is 8,700 hours. By setting them dimmer you extend the life significantly and in 20 years you can make them bright again.

awesome vid excellent fault finding looks like you have another parts board for future repairs

JOE'S classic, I want to see you use a lamp bulb tied to ground to see the outputs pulsing at +100vdc because the dvm meter is not fast enough. You have to use the lamp bulb as a poor man oscilloscope look it up and try it in your next video

Awww shucker darns Ron! Pull out the scope! Show us how to use it! 😉

Ron, we got those zombies all over this area. "Seattle" Bau, bau

Hay I see you had worked on a PIN*BOT game, one of my favorites . BLACKOUT was a great game too. We had an Arcade across the road when I was in High School in the early 80s and I got to know the owner very well . I would clean the place and I got to play a lot of free games. He had a lot of pinball games, some so old I could roll the score over and over on some of those wooden rail games. I was wounding if you have ever had a wide board SUPERMAN pinball game come through the store? I popped the glass one day and it scared the S**T out me. He made me vacuum glass out of the huge play field and helped him put a new glass on . I remember how heavy and wide that glass was . It was almost two pinball games wide and had great action , the ball was all ways smacking the glass. I told him sorry about that and he replied " Don't worry about it happens all the time, that's why I had an extra glass in the back. That thing was a monster and I have never seen one again.

On your intro duction to your videos you need to say this is Ron of Joe’s classy video games

He is off his MEDS.

Top default high score is EJB - That's Ed Boon, better known now for Mortal Kombat.

i got lost alittle with the schmatics but nevertheless 10/10 for trying to reapir those displays. I did think to myself that before you did the PCB reapir the displays were working better than afterwards. But well done for finding the mistake, easy done. LEDs look good.

The bubble means inversion. Unfortunately the exact way it's used is not entirely consistent between designers and different types of chip. On control signals on fancy chips, the default assumption is active high, so a bubble means the input or output is active low. Not everyone uses bubbles on such chips at all at all though, some use other methods to indicate active low and some don't bother to indicate it at all. On logic gates the bubble is normally just an inversion indicator. Occasionally you see "alternative" logic symbols with the bubbles on the input and the core symbol swapped (an and gate with inverted inputs is equivilent to an or gate with inverted outputs and vice-versa) where active low signals feed into a gate, but they are the exception not the rule.

We have a lot of those tweekers all over Anchorage also Ron and its getting worse.

*Joe's Classic Video Games & Window entertainment* Yep, that's the new name for the shop. =) How'ya doing Ron? Restoration looks good I see. I hate battery leakage. You wouldn't want to know how many industrial PLC's and whatnot I have dug into trying to fix'em up just because noone seems to know nil about batteries/ackumulators, my predecessors that is. If you feel really out there you could serialize a resistor on the tip of the logic probe to create a voltage divider.

Thr? I think that is the Threshold signal. That is the name of one of the 555 timer lines. I never used it in applications where I used the timer, but it is there.

Keep the good videos coming ron

The pinball machine to the left looks interesting you going to do a video on that

Oh hey arcade Matt :)

Ah ha, the scary music gets paid off! Great troubleshooting.

I noticed the traces the way they are, so if that continues to be a problem, I'd put ribbon cables there.

That's not a cheap upgrade, even though it makes sense. As for the old display, perhaps you could use a bench power supply and put 100v on some legs to see if anything happens. Maybe they died from heat though, being so close to the bottom ones, I dunno. In any case, the things can be used for spare parts on a different machine.

Sort of a shame. Nothing you could do reasonably to get the plasma display replaced/repaired. Nothing else like them. What a game though

Now its working 😁👍

@4:56 Close the door man..... you forgot to close the door. The poor soul probably did not even realise there was a door. :P We have the same sort of boxes around here.. but instead of food they are filled with books... the idea is to bring 1 book and take 1 book... or 2 and take 2... etc :-)

That would be pretty Awkward if that guy wandered into your store Lol

Here in California we have the same style food cabinets but they give free books instead.

Does the customer get the old display board back, or are you holding onto it for parts? - Oh and... THR = Threshold, which is the 2/3 of VCC point. When the voltage on pin-6 THR goes above 2/3 of VCC then the internal flip-flop, in the 555, is reset. When the voltage on pin-2 (TRIG) falls below 1/3 of VCC then the internal flip-flop is set. So, in a continuous oscillator mode, the cap is ramping up and down between 1/3 and 2/3 of vcc. Lot's of useful circuits can be made out of the venerable 555, the one in your display board is a pulse stretcher for generating the blanking period. Cheers,

@16:22 you got the middle segment there if i'm correct :)

guy was on something for sure

Please fill me in on the micro farad joke!!

Stick a neon bulb at the end of two wires and you have a plasma display driver tester._

On that new LED board why does it show you all of the segments lit on top and only the eight on the bottom is that just the way they have it configured?

Just back here for some revision as my projec Tomcat (your fault Ron!!) has just one figure missing (tens) on Player two, everything else perfect. What a struggle getting this mess repaired but we're on the home straight now! Any tips for a weak kickback?

Those are NOR gates. Without the circles they'd be OR gates. The output pin would go low if either input was high.

You gotta check out Kensington drive by Philadelphia on you tube, it's a real life zombie land.Its like the whole town on fentanyl.sad.

What do you do about all the exposed copper traces on the MPU board?

shame the dispalys couldnt be saved, how did you prove the displays where bad ?

Is there a problem with the sound board or does it need repair also?

Wouldn't it make more sense if the display had its own powersource for the 100V it uses and the control chips just control what it displays at the 5/3.3V ICs usually use?

That guy was flying on cloud 9 and was also advertising his a$$ was for sale so he could afford to stay on cloud 9. Lol

use a peak voltage adapter

4:52 that boy ain't right in the head people..we have alot of those watcha call food pantries here in nz..most of them can afford to buy their own food, the ones I've seen anyways..used to drive a truck that loaded them up every day..they'd be a crowd waiting for ya when ya got there

Was Williams like an evil twin of Motorola or vica versa? :D

Couldn't you jump the signals off of #3-4 display to the #1-2 display. You don't care if it's correct at this point you just want to see if the glass fires.

Does it work right now if you put credits on or in free play. It sure looks like it’s playable at its current state

Circle means not.. so yes, active on low

well, there's your problem, the line goes down and runs off the page

... all 7 worked on both the bottom before you repaired the mainboard, look there.. I know at this point you've already done that but hey I'm only 3min into this video.....

I know it good before iv watched it

I'd rather play pinball than pay for a gym membership

5:00 flakka

Manbaby on the loose!

Section 8

When you do the lights on this one, you might see if you want this mod done: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZCIcjVdWlCE.html

Uh, drugs r bad, mmmkay

Cocaines a hell of a drug.

Meth is terrible.