Mill Motor Control Board Repair Success!

[raynerd]

It was catastrophic failure of all proportions the other day, my mill popped, the switch tripped and the fuse was in 1000 pieces in the fuse holder. I replaced the fuse and the same happened again. Why I thought it would change I don`t know - but I continued to put in a third fuse, stupidly, but to the same effect. After the main symptons of berivement dwindled, those of anger then grief (he is a good friend and solid worker after all), I decided to go see what I could do about it. I did a bit of the usual prodding and inspecting and couldn`t see anything obvious. Then I called in on some advice from Mr Kwackers, a member on these forums. First I was to isolate the board from the power source, the fuse didn`t trip which proved that it was the board that was causing the issue.

This document was very helpful and was also taken from the HossMachine website:

http://www.hossmachine.info/Gerling%20Labs%20X2%20circuit%20board%20ServiceManual.pdf

This is a picture of a complete new motor board, which I did consider buying before Kwackers explained how to start testing it, and at £125 in the UK, not cheap:




Anyway, after determining it was the board, apparently the most likely cause of a dead short was that the bridge rectifier had blown. I desoldered this from the board (which was much harder than it was just then to write!) and tested it. Continuity everywhere between most connectors and therefore the likely cause of the short. I order a replacement on ebay and then being impatient, I decided to see what maplins had to offer in store to take away with me today. Sadly they didn`t have the exact component so again I mithered Kwackers this morning to see if any would do - there was apparently one that would be over rated so I decided to try that. When I got there I found that the casing was different and therefore I`d have to make some fly leads  to connect it up the board which was more of a pain  but finally looked like this:






I powered up and what do you know, it worked like a dream, almost better than before   .

OK - not the height of electronics enginering but I was pleased, it saved me £125 for the sake of a £2 component! ...oh and of course a few beers that will need to find there way to Kwackers. PRobably not very interesting but if someone manages to stumble of this thread with the same problem, I thought it may help them and be worth posting.

Chris

EDIT: will resize those pics shortly but just having a few computer probs, reinstalled windows and no software to do so at present.

[75Plus]

Isn't it fun to actually repair something rather than just replacing assemblies? I always make an attempt to isolate and replace the faulty part before replacing a complete assembly.

Just had a problem with my mill stopping in the middle of a task. After a bit of troubleshooting I found that the choke, just above the transformer on the right side of the board, had broken loose due to vibration. After I reattached it I put a dab of silicone adhesive between it and the transformer to secure it. You might consider doing that as a precaution the next time you open the enclosure.