Vyper68 Posted February 20, 2023 Share Posted February 20, 2023 I picked up a non working 1050 off feeBay recently and have been trying to repair it. The drive mechanism is good and the main IC’s are good and have been tested in my other 1050. There has been some attempt at “something” previously and some of the traces are damaged which have been how we say in the U.K. “bodged” the main Diodes have been replaced with some which do not tally with the service manual but may be equivalent I haven’t checked properly yet. There has been an attempt at a partial recap and it looks like the Voltage Regulators have been replaced. There was 12 and 5 volts on the board so I didn’t go too far down that rabbit hole until I really started to check the logic board. Are there any service or community mods that involve cutting the trace from CR15/16 to the positive terminal of C67 and have a wire go from CR17/18 direct to C71?? Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted February 20, 2023 Share Posted February 20, 2023 Can you take some photo's as what you describe would remove the input to the 5V regulator unless I've interpreted what you've described incorrectly. I can also see no reason to short cr17/18 to C71, rather odd 2 Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted February 20, 2023 Author Share Posted February 20, 2023 I’ll stick some pictures up tomorrow TGB 1 Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted February 21, 2023 Author Share Posted February 21, 2023 (edited) So here are some photos of the board, also the Diodes have been replaced with 1N5406 for CR17-20 and 1N4001 for CR15/16. I desoldered the wire but I have placed it as it was. I cannot decide if it was a damaged track that has been cut after some hamfisted attempt at recapping the board or it was deliberate either way the wire ( old BT solid copper phone wire ) seems to be a bypass. Edited February 21, 2023 by Vyper68 Photos Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted February 21, 2023 Share Posted February 21, 2023 could it have been modded for DC in instead of AC power? Quote Link to comment Share on other sites More sharing options...
Moonshadow68 Posted February 21, 2023 Share Posted February 21, 2023 49 minutes ago, xrbrevin said: could it have been modded for DC in instead of AC power? MMmm... Never thought of that.I was using my standard 1050 PSU and I have ordered the correct Diodes and I'm going to try to revert it back to a stock logic board and fit some new capacitors. Quote Link to comment Share on other sites More sharing options...
TZJB Posted February 21, 2023 Share Posted February 21, 2023 (edited) The diodes seem fine. 3 Amp rated for CR17-CR20 with 1N5406 being suitable and 1A rated for CR15 & CR16 with 1N4001 having the correct designation. Shorting CR17-18 to the missing C67 (not C71 which is still on the board) would short out the rectifier as that side appears to be earth. It probably needs to go to the + side of C67 due to the badly damaged trace. Check continuity to CR15 too as that may be compromised. And the 4700uF 35V filter capacitors need to be added of course. Edited February 21, 2023 by TZJB 1 Quote Link to comment Share on other sites More sharing options...
blacka013 Posted February 21, 2023 Share Posted February 21, 2023 Definitely put it back to stock. Also check for damaged tracks, and redo all the soldering where components have been replaced, and make a good job where you will add the missing components. Whoever did this needs a soldering course. 2 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted February 21, 2023 Share Posted February 21, 2023 Looks like some confusion on their part flipping the board over, not only is the soldering a train wreck, but there is solder splatter in place on resistor etc which will come lose as a flake and cause big trouble later in like. Splatter, flakes and the like are real time bomb. Back to stock is the way to go. AC power supply only at that point 1 Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted February 22, 2023 Author Share Posted February 22, 2023 10 hours ago, _The Doctor__ said: Looks like some confusion on their part flipping the board over, not only is the soldering a train wreck, but there is solder splatter in place on resistor etc which will come lose as a flake and cause big trouble later in like. Splatter, flakes and the like are real time bomb. Back to stock is the way to go. AC power supply only at that point Yeah, whoever decided to replace the diodes and the capacitors really did a number on it, but I’ll get it back to stock, even if there is a lot of rebuilding traces. Quote Link to comment Share on other sites More sharing options...
macsonny Posted February 22, 2023 Share Posted February 22, 2023 14 minutes ago, Vyper68 said: Yeah, whoever decided to replace the diodes and the capacitors really did a number on it, but I’ll get it back to stock, even if there is a lot of rebuilding traces. The diodes looks ok. They were typically elevated to help cool them a little but the capacitor tracks have been butchered but easy enough to fix. Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted February 25, 2023 Author Share Posted February 25, 2023 Well, I’ve got it back to its original configuration and repaired the tracks and recapped the board. The stepper motor is still not working properly, it’s just a really weak judder and then stops. I’m only getting 2.5v on pin 1 of jumper 15 all the others are 12v so I think IC U2 might be faulty. I’ve checked the RIOT and 6507 previously so I think that might be the cause. I have ordered some 75478’s to test this. 1 Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted March 3, 2023 Author Share Posted March 3, 2023 (edited) I have since replaced U2 on the board with a 75478 and it’s working fine now so all in I ended up with a decent 1050. Edited March 3, 2023 by Vyper68 3 Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted March 3, 2023 Share Posted March 3, 2023 nice job! 👍 1 Quote Link to comment Share on other sites More sharing options...
macsonny Posted March 3, 2023 Share Posted March 3, 2023 15 minutes ago, Vyper68 said: I have since replaced U2 on the board with a 75478 and it’s working fine now so all in I ended up with a decent 1050. Well done. All that other work you did probably will keep the drive going for many years to come! 1 Quote Link to comment Share on other sites More sharing options...
TZJB Posted March 3, 2023 Share Posted March 3, 2023 3 hours ago, Vyper68 said: I have since replaced U2 on the board with a 75478 and it’s working fine now so all in I ended up with a decent 1050. Well diagnosed. I am glad that all is working as intended. I would normally add a US Doubler at this point to support double density disks as it is so cheap and easy to do. 1 Quote Link to comment Share on other sites More sharing options...
Vyper68 Posted March 3, 2023 Author Share Posted March 3, 2023 26 minutes ago, TZJB said: Well diagnosed. I am glad that all is working as intended. I would normally add a US Doubler at this point to support double density disks as it is so cheap and easy to do. I will add that onto my todo list 🙂 1 Quote Link to comment Share on other sites More sharing options...
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