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Merry Christmas

👍👍 team effort!

hello and welcome

Good evening. No, don't jump in the water. Not now. I have a second machine to start. You thought you were out of the woods. Just kidding. With everything I've learned from you, I should be able to do something on my own. And if I can't, well, I'll come and ask. Thanks again, gentlemen.

Felicitations mon ami. J'ai cru que j'allais sauter dans la Tamise.

Bravo!!! Bravo! 😀 RP8 is the culprit. Incomprehensible. I desoldered it and tested it outside the MPU; it's fine. I had tested it before, though. On the MPU, RP8 is allowing 5V to pass through. I'm very happy, very happy to see it working. It's a bit of an 80s nostalgia trip. I'm going to fine-tune the settings and run the test mode. I want to thank the contributors, Midibob, Andrew96, and Jimxxx, for their expertise; without which, I wouldn't have achieved this success. 🤝 Truly, hats off to you. Sincere thanks. I hope this thread will help repair other MPU3s. Gentlemen, thank you again.

So, with D40 with one leg sticking out, I'm getting 5V. Okay, I remove RP8. I resolder D40; and there; it's good. I test RP8; it's OK. This is all very strange. Continuing with this, I'm going to replace RP8. We'll see.

So, I just ran some tests. IC5 removed from its socket. Green connector unplugged. I traced each trace, tested each trace, and checked for short circuits with neighboring traces. Nothing. And I have 4.6V on pin 10 of IC5. (PB0) So, I think in this case, D40 can only be faulty. I can't see anything else. I'm going to take one from another MPU. Thanks

Hello. So, I didn't understand everything. (Ah, translation!) But the main point, yes. I tested the 100-ohm resistor; it's OK. I checked the green wire and the green socket. OK. I unplugged the green connector from the MPU. The voltage is the same as in the schematic; previous message. I'm starting to think, like you, that the voltage is coming through the 6821. I made a table, remember? We're on it. I'm going to check my solder joints in that area. I'm working with a magnifying glass and light, though. Thanks again and again.

Hmm, that might be telling us something! Pin 5 on the green plug has 4.8v on it and it's slightly lower on pin 5 of RP8 so it could be coming from the other end of the green cable somewhere? The other end of the green cable should connect to pin 4 of the 4049 (via a resistor) which should be at 1v. So check the 100 Ohm resistor that is in series just to confirm it's 4.8v one side and 1v the other and that it's still 100 Ohms. The other possibilty is the voltage is being supplied by the 6821 (the readings are very close) in which case I would have thought it's either got a bad port or you may have a solder bridge somewhere perhaps under the socket? If you lift that one pin out of the socket and put the chip back in you'll soon find it. Hope that all makes sense.

Good evening. Yes, I confirm: ground; negative; 0V compared to the main board. Here are the measured voltages. Machine is in standby, ready to play with credit. Thank you.

OK, that would suggest the sensors are OK (which is a pity). I can't think why pin 4 is different albeit it's only 1v. Might be worth checking to see where that voltage is coming from, the other side of RP8-D40 and compare with the others. Can you confirm the ground you were using to take these readings is at the same potential as the ground on the main board?

Hello Thank you for always being present on this topic. I'm here to correct my measurements, which weren't taken correctly. I did indeed use the wrong ground connection. My apologies. So, here are the new voltage readings. See diagram. There's still a difference on pin 4. And now, the probe in this configuration is working correctly. I'm getting a high and a low reading depending on whether the light is passing through or not. Thank you

That doesn't seem correct to me? Where is the -ve lead from your meter connected? Can you check that pin 8 (4049) is at the same potential (ground). You shouldn't be reading negative voltages?

Good evening. I'm just giving an update. I ordered some sensors. 10-12 days. I've been testing the 4049. I don't know if this method is valid, but I can't get it to work with the logic probe. It doesn't seem logical to me. I measured the voltages on each pin by rotating the roller to get: sometimes the light, sometimes it's off. Only pin 4 is different. I've swapped the 4049 three times; same result. I've swapped the sensors twice, same result. I've cross-checked the swaps to be sure. I see that the four sensors are equivalent. 5-7-9-14 6-10-15 are equivalent, but not pin 4. So, I don't know, this is where we jump into the Thames or the Seine. THANKS.

Good evening. ""We can all jump into the Thames (or the Seine)"". 😄 😄 😄 Thanks for the reference, I'll order it. I'll check for 4049. Thank you.

OK, I think we are close.🤞 I have used BPW85C before and they appear to work OK. They are very sensitive and are 25° receiving angle so maybe not as narrow as the originals but I've not had any comebacks from users. As a final check for PB0 you need to confirm that the output from the sensor is going from high to low (it may not go low or high enough!!) to trigger the chip on the reel board. So monitor pin 5 on the 4049 chip and then check pin 4 is going low/high like the others. I'm only suggesting you do this to check the complete path back to IC5. As Andrew states, swapping out the sensor will most probably sort it. If it doesn't we can all jump in the Thames (or the Seine)

Hello I just tried some other sensor modules. I had some from another unit. I took modules 2 and 3 from the other unit to replace module 1. Same result; same as the voltage chart above. Same error. I just double-checked the solder joints; they're fine. No dry or cracked solder joints. The green wire is OK. I'm going to try to find some sensors to replace them all. Not easy without part numbers. Thanks everyone.

also check the soldering on the reeldeck connectors board, these crack and go dry jointed

hi jim , i see what you are saying but it is very possible on your point 1 that both decks have faulty sensors, the machine checks them all but reports the errors in order, so if reel 1 fails it will show the hold light lit and stops checking the rest, if that's ok it moves on to checking reel 2 then reel 3, the opto sensors are around 1980's so around 40 years old and in my experience are a very common failure these days, so it may be actually one or more sensors are bad. I seen people swap them around on the deck and still have the same problem because others on the same deck are bad but reel one is always checked first by the software. the sensors also go intermittent, work one min and not the next, that's also how they fail too. you could indeed be right on the cables and plugs, they tarnish with age and cause problems. it could also be the chip on the reel deck although that failing is much less common

Hello. Ah, yes; okay; I understand what you mean. Translation, sometimes... Yes, yes, I've grasped the whole system. Andrew; thanks. I have another roller assembly; I'll replace the faulty one. And redo the measurements. It doesn't hurt to try. Jim has some ideas. I'll double-check the wiring and soldering. Thank you. Thank you, gentlemen and have a good Sunday.

Sorry to interject here, i am enjoying following this thread and looking foward to seeing the machine run. As an outsider looking in sometimes you notice things that might help (or might not). 1. You say in an earlier post that you have tried a different reel deck (roller block) and the same fault still exists, this would mean that you have two reel decks with identical faults which is possible but unlikley. So can you confirm that the correct signals are leaving the reel deck (Bob or Andrew can talk you through where to test on that). If the above is not ok then it would seem the fault is with the reel deck. 2. If the above is ok then can you check the continuity of the green wiring loom between the reel deck and the mpu, also the green socket on the mpu and reel deck ( i can not see any mention of this being checked in previous posts). With the reel deck disconnected the mpu will see a fault and i imagine it goes through a sequence where it checks reel 1,2,3,4 and if there is no reel deck the first fault it will see and report is reel 1, again Bob or Andrew can confirm this. I will go away now and continue enjoying this thread. Jim Ps, as a relative newbie myself to the forum i would just like to say how good it is and the great people on here with the help and expertise they freely give, Well done everyone.👍

this

good evening Sorry, I don't understand your first sentence. the lit HOLD corresponds to roller 1. Pin 10. As I said before, I would like to change the photo-sensors but I don't have a reference to order the correct ones. Do you have one? Another question; please; Why; the same error, roller block disconnected. Thanks