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Yes tried another ls08 in a socket, was thinking IC23 I wish I knew for sure it was a switch issue, will look at the pinpoints for the 138 and maybe probe it for stuck outputs ? thanks Ronnie

I don't think there's even a RESET, it's a two wire serial link! I need to set this all up on the bench but 4x20 VFD's cost about £100 a pop!! I've bought an LCD with a serial i/f and will have a tinker with that. Whether it'll do anything or not I've no idea yet but the learning curve will be of value.

Did you not try a new LS08? (always put a socket in ) Lets hope the PIA is OK, it goes via the LS138 (IC23) first anyway. You can always scope the outputs from the 08 chip to see if all is well there. You could have shorted/leaking diodes too. Luckily yours are all separate and not in those horrible 8 way blocks! Both IC33/34 can also be responsible for weird switch issues but easy to check out with a scope.

I removed the Ls08 and tested it in my programmer, it passed the vector test, not sure if this is a conclusive test? The resistor I replaced did not burn again, if this IC is ok could it have damaged the PIA? I wish I knew what the error code meant. Thanks Ronnie

Awesome... save some pc92s for the rest of us 😅 Yeah see that is strange as Chico is in the cabinet before the front opener? So if thats got the bacta keys but they're not in the later Theme park... could have been some loom pillaging going on at some point with the TP. That does sound like a ball ache... magik is way better on displays than me. How many wires going from the little display board to the display... the usual +V GND Reset Sclk and data?Recently had a ball ache with some 5v vfds myself stopping an m1 machine from booting. Not something like a hole in the Fet? The main problem is you can't really find other parts to swap that so gotta probe it all out.

Thanks bob I’m suspecting the ls08 I guess I could probe it but may as well just change it

That output through the burnt resistor is part of the switch matrix, it that's not working right you'll get all funny things happening with the switches.

Not quite yet. We go off on a bit of a tangent here so bear with me.... I'm also trying to get my head round Chico the bandit. Again no info but have been following Magiks superb vids on Youtube. This does have a stake key fitted and that might shed some light but meanwhile this one has a few funnies of its own. A large 4x20 VFD that doesn't connect to the VFD socket, yep you heard that correctly? It actually connects to the 14 way DIL socket as a serial interface. Not only that it has it's own little display PSU board. I'm trying to get all the info on this so I can get it documented as I know it caught Magik out when he encountered it. So at present lots of head scratching and wire tracing to be done. Will update when I have more info.

Any joy with it Bob?

So I removed the burnt resistor, the diode checks out ok, I test fitted the board, the alpha is back, it reports error 4.0 unexpected PO, I suspect it was doing this before I could see the alpha and again pressing any button resets the machine, away to look at error codes, maybe fit a resistor back and see what happens? EDIT new resistor fitted, no change

Thanks Adrew, will check that diode, will that senario likely have killed the LS08?

the burnt one will be the same as the other 3, 47 ohms, check the zener diode, it's 4.7v the same as the other 3, this damage happens when someone connects a switch up incorrectly and sends 34v from the lamps up the switch matrix! so check the switches are wired correctly and not transposed with a lamp connection!

It may have taken the 74LS08 with it so you may have to do both. As to a cause, not really sure, maybe a short to 5v or 0v back in the loom or switches? I've had a few in recently suffering weird intermittent faults due to corrosion getting in to the cart socket. No amount of cleaning made a solid repair so they had to be swapped out which is a real pain!

Thanks bob not at all, all advice is welcome especially from you, I have ran 7 jumper wires already but component side! Still about 3 to do. I will look at what you Mentioned tomorrow any idea of the fried resistor bob? cheers Ronnie

Nice clean cabinet, shame about the battery vapours. I always do the fingernail check on those little caps C9-16 and if any of them come I apart I swap them all out. I also check that all the tracks to the associated zener diodes and caps are valid to the triac driver transistors, it easy to miss. C47 will need changing too and make sure it's ground connection is valid as the track has all but disappeared. I usually stick a rivet in the battery terminal and run a new bit of copper back to C47. You may find the positive battery terminal has rotted back to R72 as well. All 10 of those transistors in the view will need changing even if they look good. With the rotten tracks to the Alpha I stopped trying to do them on top of the board and now run patch wires underneath. Hope I'm not teaching granny to suck eggs here. Good luck.

As suspected battery has leaked causing localised damage to the tracks under battery, some repair needed! Battery snipped and board cleaned up with IPA then washed, damage not too bad, seen far worse! T13 fell apart. I'm not too sure these tracks would stop it booting fully up? I did notice R83 near IC22 has cooked! looks to be on the switch inputs? I did notice when I power the machine up pressing any button eould cause the reels to spin up again, maybe a reboot?

Picked up this one very local to me, not my era but thought worth saving, seems to be a good game from the 90's just pre MPU5, suprisingly it does boot but only spins up the reels, nothing else! No alpha, prime suspect is battery damage to tracks under! To be continued..................

Very impressive collection i must say. I wish i had your dedication, i buy and acquire kit like that with the intention of doing them (some do) but then get sidetracked and they end up on a work in progress pile that seems to keep growing. Some of my pile below 😂

Try changing the THEME to NEW DEFAULT. that usually lets you see the forums.

every threads I cant get in to read. is this forum broken?

Yep, for a long time: https://www.radiomuseum.org/collection/piotr_jachymczyk.html Also mechanical and early electronic calculators (with nixie tubes). I will have to buy one then, it may come in handy. But still, electromechanical logic is the best for me - like those Rotamint etc. German machines.

Older electronics....... Valves? 😀. So 6800 processor, 6810 ram and 6821 pia, pretty basic set up really. The roms (2716) should be able to be read by any eprom programmer even the cheap chinese ones. As Bob quite rightly says best to get them checked first and if they are ok get them backed up.

Exactly, it's a timer MC1455. As for the processor it's Motorola MC6800L along with MCM6810 and MC6821. ROMs are HN462716G. I must say, I never dumped any ROM, it's completely out of my expertise, I prefer older electronics. What would be the best way to do this? Maybe I'll ask around and there would be someone nearby...

The game will be on those ROMs and I expect they are rare as hens teeth. I would get those dumped and hopefully they are good as if not you could be wasting a lot of time. Does look like the precursor to BlackBox, the RAM board looks almost the same. Chat GPT thinks it's a Z80 but I doubt it?