Leaderboard

Not written up an MPU4 for a while so .... This one came in doing all sorts of odd things before it died so I suggested sending the PSU as well just in case. The PSU was fine and all the caps had a good ESR so that rules that one out. Moving on to the board, most of the components around the battery area needed replacing and anything else with green legs. On switch on it did boot but with garbage on the alpha and then nothing. Luckily there was no track damage which was confirmed by tap'ing out the tracks to the alpha. In fact the only track damage was the negative battery pin which had become isolated. A rivet and some copper sorted that. So where do we go next? The first diag test is the triacs and all was good in that dept being as I'd alread swapped out all driver transistors, the 1nF caps and the zener diodes. This comes from IC8 which also has a drive to the alpha. The other drives to the alpha come from IC3 (68B21) so out she comes, in with a socket and a new one and bingo it now says MPU4 ALPHATEST OK. Are we done? Don't be silly, up comes the 7 seg display then it alarms with something like @@@@@ALARM 7xxxx (some other odd characters). Usually once the alpha is working it will tell you what the next error is but in this case it was garbage. The next thing the diags test is the RS232 and the meters (could be the other way round I can't remember) so I blindly changed the two IC's responsible as neither of them were producing the required outputs (IC7 + IC5 68B21). Next boot up and it's still the same.OK, I have seen a 6840 ALARM around this stage so a quick swap out and ....nope! Next thing switch on again and nothing??? The RESET circuit has failed. Should have swapped out these transistors originally, ho hum. So I'm running out of IC's to change so where next? After being on a few minutes with the alarm sound driving me mental I noticed IC6 was cold whereas all the other PIO's were warm. Hmmm, in with a new one and everything sprang to life. That was a relief.

Looking like a machine now,but still lots to do.

Machined playfield today, now to make the ball release bar.

Wow, I can't believe I haven't updated this thread for nearly 4 years! Anyway, back in the workshop this board came in as dead and it was, totally. First check was the 5v rail and it wasn't there! No problem as quite often the LM723 fails except in this case it was a later mod with a 5v reg TO3 transistor. Checking it had 15v (ish) on the input which it did but nothing on the output. Unusual as these things are supposed to be short circuit protected. To cut a long story short there wasn't a short on the board but the acual reg tranny had gone short on it's output. OK no problem there, slip in a new 78H05 and off we go, happy days etc!! So on power on we get about 4.5v slowly rising towards 5v (that's not right) followed by a 'blimey that's getting hot' smell. Quickly turning it off I found two of the 6820's had turned themselves into hot plates. Whip them out and replace with 6821's (slightly less rare than 6820's). Switch on again, nice 5v and nothing! I'm now off the opinion before the reg went short it passed 15v out on the 5v rail! The other two 6820's were both faulty too but cold. Once new chips were fitted there was activity so the CPU looked like it was OK? Due to the PIO chips being damaged I decided to check out all the TTL chips too. Two of them were bad but I decided it would be prudent to swap them all out as a precaution. So now I have all the chips socketed and Bingo she runs (after a few silly bits of diagnosis that we won't go into here ) 6820 CPU's are become scarce now so I was pleased it was holding out and has done after several hours per day of soak tests. There's no thyristor over voltage protection on this mod but it was brought back for MPU3 no doubt for good reason.

Wheels and bearings in,motor and clutch now mounted.playfield artwork ready.soon be putting electrics in.

Cabinet looking good and fits and locks very well.now time to get playfield done and make final holes in front pannel for coin slot,payout and release knob.

Moving on.i now have my metal parts.been working on cabinet today.now being assembled. Hole is now cut for top sign and mounted playfield to front pannel to make sure it fits.wheels assembled onto drive shafts.lo5s to do.

Enjoy.. I took all images off ebay Figured they were worth sharing here Happy days

I've got all the books from back from the printers now so will be messaging everyone privately who ordered them for payment and then I can get them all sent out. Postage comes under 2kg for 1 so can send one for £3.50 or more for £6.65 total. I do have a few spares if anyone else wants them as a Christmas present for themselves or to get one of their wives/partners to buy for them? Here's a few pics from the finished books. Thanks Greg

Made the brackets to mount ball tracks and playfeild surround is on with inlaid lights to illuminate playfield. Getting wood for cabinet Tuesday and coloured discs for wheels.i can make front of cabinet and measure for glass front then I'm stuck till all my metal bits are done.jjust to add its 8mm pitch chain not 3/8. I've had that many measurements and bits in my head I got mixed up.

Hi guys,I've decided to build myself another conveyor,I'm currently searching for the bits and have some already.i made 5 in 2010 but rarely come up for sale.this is scratch built Inc cabinet and even make my own payout mech.so who is interested in a thread following the build of this.

Now doing the 4 wheels.

Same as tilly greg .got mine this morning so a massive thanks for doing these books.cant wait take a look at them.

Thank you very much Greg the hours and hard work you must have put in to getting all these flyers together to produce these 3 volumes , I got mine in the post today they are fantastic and really high quality GREAT JOB! 👏 , a brilliant Christmas present even if it is to myself 😁cheers and merry Christmas 🍻 I will certainly be up for the next volume £8+ when you put it together 👍

Now got front pannel together,drilled and dowel joins.dowel jig shown.so just layed things together to see how it looks,now to do more work on front like rebating for glass and top flash.

Well, I've finally managed to collect this unusual machine. It IS, thankfully, all original as far as the coinage is concerned, and has the longest hand-fed token column I've ever seen. As an added bonus, this column is three-quarters full of the famous Bell Fruit 'Lucky Symbols' tokens! I'll be on with it this afternoon ...

Cheers mate,waiting for my metal work now which might be a couple of weeks,will post as I do more.

Wow! That's come up beautiful 😀 I used to love these old BWB games. There was another one like it called Windfall, with apple-cores on the reels instead of coins. And then you had Win Strike, Rat Race and so on. A great era of 2p fun 🙂

Hi all, sorry about the ridiculously long gap between posts but work has been manic. Well the machine now lives on and is working perfectly (except for the payout mechanism) thanks in a massive way to @roadrunner who has managed to save the machine. After a chat with him I sent the board and drive to him and his incredible skills repairing the board and disc drive got it up and running again. I did have a strange issue with the back door switch which turned out to be faulty and kept rebooting the machine and then switching off the coin mech light. Once this was sorted it was all good to go. It's been a real trip back in time and my friends and family have loved playing it while trying to throw the brain back to early 90's. I'm absolutely delighted with it, the only challenge other than trying to win was finding old coins which my son finally did. A big thanks again to Roadrunner for all his assistance including tech support in getting it going. I'll try and post up some pics and video if I can. Not sure if video will be to big! Chris IMG_0824.mov

Originally from 1942,mine is smaller.I made 5 of these in 2010 as in pic.i will update as proceed,you can see the parts I have got so far and wood collected today to start playfield and surround.hope you find this interesting.

There's nothing wrong with the original, I need a copy for a machine that doesn't have one

Yes, will send it at the weekend.

Thanks, Bob, I will do that. I ordered all the components in this area, so I hope that it will be OK after that. Yes, the fingernail test is very effective. See you soon.

Great Christmas present idea for the misses lol Divorce material lol Jokes aside good luck with your venture greg

Hi everyone. Thank you Bob for your help. Today I found an anomaly but did not have time to correct it. I checked all the components of the reset circuit, everything is OK except R12 (2,2K) The controler did not indicate the resistance value and when I unsoldered it I saw that one leg was broken. It was impossible to see whithout removing it. I'm shure that I have one somewhere in my stock, I will replace it tomorrow. I hope it will work.... See you tomorrow.

With the letter L on the silk screen it looks like an inductor. From the picture it looks like Brown black yellow silver That’s 100mH with 10% tolerance

Hi Andrew Just as an update - I cleaned the game card with a cotton bud and some Isopropyl Alcohol and I noticed some brown residue on in the area near the capacitor marked below. So this looked to have been leaking. Luckily, there didn't look to be any damaged traces or corrosion on the board. So, I ordered some 10uF 25V SMD Aluminium Electrolytic Capacitors and swapped this one out. Please don't look too closely at the soldering job. I am just a keen amateur 🙂 I had to reset the time and date after the works just once but after swapping out that cap the system has initialised and booted up every time without the 52-36 / NO ID CHIP / NO CHARACTERISER error. Although I ordered it, I did not replace the battery in the end. Obviously other people's experience with this might differ.. but, at the moment... fingers crossed, the unit seem to be OK.

Got the wood for cabinet and wheel artwork today.

OK, this is not unexpected when tracing faults on this board. You need to understand how the RESET circuit works otherwise nothing will make any sense. You won't need a scope at this point (probably later though). A quick overview.... all the supplies are monitored via diodes feeding in to TR10 and/or TR8. You have to find which supply(s) failures are getting through the diodes to cause the RESET to occur. 1st to check is IC2(8212) as this often fails, they aren't cheap either! With these boards I usually change all the transistors TR 8, 9, 10, 11, 12, 47, 48 and some others but more on that when you get it out of RESET. I can't emphasise enough the pins in the PSU socket, if these are contaminated you'll be getting RESET's intermittently all the time!!

Hi Bob, Hope your well, can't remember if I ever got to the bottom of it, I'll blow the dust off my notes next week and have a look.

Another odd one... After doing the usual component replacements, firing up and running the diags all was good. After this and before the soak test on my Cabaret machine I plug in the 'Strike it rich' game as it uses an alpha. Just to note you can't do this on the earlier mod MPU3's as they don't have enough RAM unless they have the daughterboard with extra wires but that's another story! So back at the ranch, switch on and no boot??? The alpha backlight comes on but no characters also there's no reel spin. What's going on here? Next thing to try was 'Line up' as this is an intermediate game that should run with earlier Mods. This boots and sometimes the reels don't spin properly but then it just alarms. Back in with the diags and everything is 100%? When I first looked at the board it had already been repaired at some stage and IC4 & 5 (6821) had been changed but not using proper IC sockets just single strips. I hate repairs done like this so out they came and new sockets fitted. Looking closely at the 6821 chips I could see they both had exactly the same markings which I seem to recall from pictures on Ebay of Chinese 6821's. A quick rub on one of them with acetone proved they were 'blacktopped' and sanded down so impossible to say what they were originally. Most unscrupulous sellers sell these remarked as 68B21's whereas they are really 6821's and slower so in this case I couldn't see what the point was?? Replacing these with a couple of known good test chips and switching on........exactly the same. So it's off to wild goose territory and because the alpha didn't come on I thought I'd swap out IC6 (6821) and of course it was innocent. After a fair bit of head scratching I started testing with the alpha game again and noticed that when it tried to boot everything on the CPU was running and then just stopped? No reason for it so the only thing I could think of was to change the CPU. Blow me it all worked, I've not come across that before and probably never will again. The two 6821's of dubious parentage were put back in and appeared to run OK. Time will tell on that one.

Watch out for the tracks near the battery area being eaten away. It might look good with the solder mask covering it but you may find there's no copper underneath. Crazy but true. Always good to tap out the connections to confirm. Don't want you saying 'zut alors'! Here's one I did a while back with the track repaired and rivets fitted. If your PSU connector sockets are contaminated I would get new ones otherwise you'll end up with many intermittent RESET problems. Bon chance.

I found this, it's great, just what I needed. First, I will replace the damaged components 🙂

Was a decent game, obviously would have preferred the adders and ladders it once was, but better than it being sat as fire wood. off to its new happy owner already. Another one rescued and saved 😇

ok, so I only have mpu3 reel board circuit, but that also uses a 4049, so working from that the sensor supply is 5v through a 330k resistor, so the max current flow through the opto sensor works out (with ohms law, you can check it yourself) at 15uA max current flow, so if MPU2 uses the same these will work

They switch a 4049 chip and without looking up the datasheet I've got no idea what the input switching current is although it is likely to be very low of course. The main issue I've found during experimentation is modern devices seem to be much more sensitive and any stray light sets them off. The caveat with that is I didn't know what the angle was of some of those devices. The old adage I always use is 'suck it and see' bit like oral sex really!

I've cut and shaped the wheels,made 48 long pins and just starting the 24 short pins.also started assembling the 8mm pitch drive chain.now measuring for the drive shafts and bearings that mount to playfield. Note the wheels are slightly tapered to help the ball go through lose hole.

Still getting materials and tooling.its a scratch build so quite involved.should hopefully start this weekend.unlike my other veneered cabinet this will have a solid oak cabinet.

try a 200mH coil?

That is exactly how it is wired on the pcb, confirmed!

thank you

Happy days

Test across it with a multimeter set on the ohms range and see what it reads.

Really looking great Simon 👌

You'll have it done by the end of the week. Great work

The datasheet states if the voltage is lower than 1.15v on pin 3 the output will go high so with 1.7v pin 4 should be low. You can remove the chip to confirm it's faulty as the board will run without it. What you may need to do is see if any 'high' states are coming via any of the blocking diodes from each of the supply lines as this might not be the only one. If you're lucky it might just be that one. You'll soon see as the cathodes of D21 and D22 will (or should) both be 'low'. Don't venture on to other pages of the manual just yet just stick with sheet 7 as that's more than likely where your main issue is. For now anyway.

Hi everyone. Using the parts list, I ordered the components I needed. I'm waiting for them. Meanwhile, I read topics about system one, so many things to read... I removed all the questionable components with damaged legs and I redid the copper tracks with copper in rolls. I hope i will be OK. If I understood correctly what I read, le led on the CPU must firstly light up and then go off if the reboot is correct, is that right ? I was happy to see le led on all the time 😂 The card that I try to restore uses only two eproms. They are OK, a friend of mine tested and copy them. Here are the bin files, maybe useful for someone. Jolly Imperial V.zip

Yep definitely simon .don't know much about them but would be interesting all.the same

The CD4049 ic Supply Voltage (V+ to V-). . . . . . . . . . . . . . . . . . . . . . . -0.5V to 20V DC Input Current, Any One Input. . . . . . . . . . . . . . . . . . . . . . ±10mA

Druid now dumped and uploaded on DIF. https://www.desertislandfruits.com/forum/index.php?/topic/18144-mpu3-rom-dumps-druid-5p-£150-big-game-291fl-lucky-strike-101/