Leaderboard

Just to complete the my introduction to the forum I thought I better show what fruitBar is as I guess most people will just be wondering... I would of posted an image before but I was not on a PC at the time of my original post so I didn't have any screenshots.

I can't say I ever get angry enough to do that. Normally just a shrug of the shoulders and go and make a cup of tea! And so on to the last one. After yesterdays success the first thing I thought I'd do was to check all the DATA lines but this time all were in order. They do say lightning never strikes the same place twice! So where do we go from here? ADDRESS and DATA lines are all running but there's no IRQ on the CPU (pin 20). This called for a quick check in the Midibob book of horrible faults. Page 1, don't jump in the Thames! (or 'DON'T PANIC' if you're a Douglas Adams fan) If the board doesn't boot and you've tried everything else, before you start lifting all the PIO's start with the SIO. Blow me, hole in one! The SIO chip was bad. In with a replacement and BINGO she lives. These boards will actually fire up without all the PIO's but not the SIO, which is good to know. This set of Procon boards has been a real challenge but I've managed to succeed and keep my sanity. Time to move on to the next box of faults as I've got quite a few folks waiting and still unopened boxes in my hallway. Repairing boards is one thing but keeping the missus happy is something else!!!!!

Repairing boards is one thing but keeping the missus happy is something else!!!! Well Bob you know what they say a happy a wife a happy life .... Well we do try 🤣

Definitely not a false memory as the machine would be Ultimate Nudge from Summit Coin Circa 1982. I had one in my garage many years ago now and it moved up to Scotland.

It can all be followed and downloaded here, https://www.desertislandfruits.com/forum/index.php?/topic/9585-fruitbar-mfme-front-end-system/&tab=comments#comment-75826

Can anyone remember a machine that that said "Nudge UP, DOWN and SIDEWAYS"?

Thanks J I thought i would branch out a little and see what other forums are around

And the wipers were designed to go in one direction,so really very bad conversions

I think I'm correct in saying the only Bell Fruit machines that have reverse nudge are MPU controlled. The electro games with reverse nudge were conversions by other companies.

Down to the final two in this present batch and of course I always leave the worst till last!! This one wouldn't boot and I couldn't see why not? There was activty on all the DATA and ADDRESS buses but nothing happened. Someone had had a good go this already and 4 of the PIO chips had been socketed and swapped out. In the head scratching that followed I socketed the other two so that I could test all the chips in a good board. So all PIO's and SIO tested OK. The CTC was then swapped but still the same. The RAM was already socketed but a replacement also made no difference. Attention then turned to the Synth chip but that proved to be innocent as was the CPU. Next stop the Thames I was thinking....... but one last thing was to check all the pull up resistors to the buses which should all measure 10K Ohms. As I was checking I noticed two of the DATA lines only measured 5K!! Blow me there was a short between D1 and D6!! As I've mentioned before trying to trace the PCB tracks on these boards is horrendous and if you have a short it could be anywhere. With the panic hat now removed and logic hat back on I thought it had to be caused by the previous repairer and that indeed was the case. The only place I could see where the two DATA lines were anywhere near each other was under the RAM socket so a quick removal was in order. Once I'd seen this I was cock-a-hoop as I new I'd sussed it. Can you see it? Once cleaned up and the socket re-fitted and chip put back in I was thinking it'll be time to wrap up. Shriek, it still doesn't do anything! The short had definitely gone but not a dickie bird. Quickly slipped in the test RAM chip again and BINGO she lives!! Phew. This is why repairers always hate it when a board has already been worked on as any faults unknowingly applied can be real pigs to find. OK so now I have a functioning board I can actually do some testing. First thing that became apparent was some of the 7 segment displays were showing extra segments. I've seen this quite a lot recently and it mostly due to the 100 Ohm standoff dropper resistors (bottom left hand corner) which get bashed about due to poor storage. They then break their solder joints and touch each other.

On the note of the actual thread….. if anyone’s interested now. Pic chips for certain machines are available off this company at a cost of £25 plus vat and delivery. I emailed regarding one for £25 Addams Family ROMs and they have the one needed a BC025. if anyone needs one give them a try. Chris Street emailed me back in no time with a yes we can and price. They also supply ROMs if you don’t have anyone kind enough to flash them for you, thanks to the Mecca I am lucky with those :-) good luck all.

.... and some more. On switch on the board would clock up 18 credits, in fact every time it was switched on another 18 credits? Sometimes just touching the coin inputs with the scope probe or the meter would clock up credits. This little head scratcher turned out to be the 12v supply feeding the coin mech. Transistor T95 had a broken leg and hence no 12v was delivered to the coin mech so the inputs were floating. This was caused by bad storage of the board and it's a real bug bear as I see so many faults similar to this with broken/crushed components, broken tracks due to a deep scratch etc etc. Still, all in a days work. Had a couple that were dead but looked like they should be running? Previous repairs had taken place with regards to the transistors in the reset circuit but what hadn't been checked was the resistors. It's always good to change all 8 resistors in the middle and the three, or even four, at the top. I always use the fingernail test, applying slight pressure to the side of the resistor. If they are really bad the wire comes away from the body. They usually have green legs but not always so don't be fooled! In this case one of the 10K's failed the fingernail test and another one fell apart on removal. You can do a manual reset to prove the rest of the board is OK just by momentarily shorting CPU (26) to ground. If it then boots you know the reset circuit is misbehaving. Another real head scratcher was the reels not spinning correctly (or at all). I use my Arduino to fake a reel set and I have LED's to indicate the motor drives. In this case there was no drive to the odd reel motor coils although the evens were OK? This was a PC 92 and the reels are driven, odds from IC1 and evens from IC2. There were no outputs on IC1 whereas IC2 looked fine? You'd obvioulsy go straight to IC1 and swap it out but then what do you do when the spare is exactly the same! After not too long (I surprised myself here) I thought I'd just check the signal paths and eventually got round to the DATA bus. All were showing a signal on the scope but D7 didn't look right. It looked like there was lots of information missing due to big gaps in the waveform. Checking D7 on the CPU showed what I expected to see so I'd sussed it there was a break somewhere. That was good news as it's faults like this that cause me to jump in the Thames! If you've ever tried to trace a track on these boards it's horrendous, and for the life of me I couldn't find where the connection was between all the PIO's and the main DATA bus back to all the other chips. To make some headway I just put a tack wire back to the CTC chip and BINGO all the motor drives were now working. Get that wine bottle open!!