Leaderboard

this should help - note the notches on the proms

I already have a couple of working mpu3 machines but no experience of fixing anything inside the metal box. I decided to have a go at building some experience so I’d have the confidence to try and fix any issues that might arise with my working machines. I purchased a non-working Royal Exchange and didn’t pay a lot for it but reasoned with myself that if my project failed then I could always sell it on or break it for spares. But I only want to preserve it and get it working!! I have no contacts to call on for help, but I’ve found this forum is a brilliant resource for people like myself who are willing to have a go. I’ve been logging everything I’ve done so the following posts detail my journey so far. The story so far part 1… Power on and Royal Exchange not working, only 2/3 flo tubes lit. I replaced the ST111 starters and all the flo tubes, then checked/replaced all the PSU fuses. The mpu3 board is a Mod 5 with a daughter board and 6117 RAM. No battery on the board but it was evident the old battery had leaked and done some damage as there is some masking missing. Someone has previously cleaned the board up, but upon first inspection I found quite a few green legged components, also T60 had a broken leg and C41 was missing. I replaced T60, T61, C41 and R92 – R95. I also cleaned between tracks with a fibre pencil and mopped up with IPA. Checking the white power plug I found that the 12v return pins 1 & 9 had burnt. I then fitted a bypass lead to 0v on the board as suggested elsewhere on this forum. I checked pin voltages on the white power plug and all OK. I fly wired a NiMh battery, confirmed 5v at the link and pin 24 on 6117 which dropped to 2.4v on power off. After cleaning all the plugs I connected the board and switched on… it booted but was stuck in reset. Reels stepped up & down and remained stiff, optos lit and display was now showing ‘Resetting RE 4.0’.

It is so funny but not that in the early days we would trust people more than computers.

Looks amazing 👌

You will find that there is the good, the bad and the ugly in the real fruit machine world, emulation world is not far behind either. There are those that withhold many things and you will find those that are friendly to your face then talk shite about you behind your back, that is not users that is just people.

only got this ? chloe

Welcome to the world of frustrating MPU3 faults. A few things you need to check, the 500HZ osc from the 555. Both the 10K timing and duty cycle resistors can go out of limits as can the big 0.1uF cap. Do IC9 and IC24 show any signs of the green plague on their legs, if so replace them (in sockets). The RAM sockets can be an issue as they are the 'stamped' type but due to the fact you have the daughterboard you can't fit the more reliable 'turned' ones. Sometimes contact cleaner will work but again any signs of the green stuff, whip em out! Don't forget to clean the legs of the daughterboard too and check the state of the actual RAM chip socket. The ROM cart socket can give you grief too if it's dirty or lost tension on the pins. A bit of contact cleaner and a very fine (and I mean 'very') emery board works wonders. Also if the little silver key spacer is broken (very common) the cart can just be out of alignment enough to stop it booting or at least become intermittent. See how you get on with that.....