duntokin Posted October 18, 2005 Share Posted October 18, 2005 Hi - my first post and I could do with some advice. I'm using an alcora 12 channel desk into 2 tempus 12 dimmers via a strand demux. on 1 dimmer one channel is completely dead ( fuse OK) and on another it will fade up to about 70% and then black out if pushed higher.- which is all somewhat annoying. Could it be the triacs are dead ? The dimmers are very old but in good condition. Thanks for any help in advance Moderation : completely unnecessary font colour, size and formatting removed. Ordinary plain black standard-sized text is just fine for posting - anything else will only serve to annoy. Please don't do it again. Link to comment Share on other sites More sharing options...
gareth Posted October 18, 2005 Share Posted October 18, 2005 Hi - my first post and I could do with some advice. I'm using an alcora 12 channel desk into 2 tempus 12 dimmers via a strand demux. on 1 dimmer one channel is completely dead ( fuse OK) and on another it will fade up to about 70% and then black out if pushed higher.- which is all somewhat annoying. Could it be the triacs are dead ?No.1 sounds like it might well be a dead thyristor, yes. No.2 - try softpatching the output to a different fader, and see if the problem still occurs. It sounds like it might possibly b e a break in the track inside the channel fader. Link to comment Share on other sites More sharing options...
dbuckley Posted October 19, 2005 Share Posted October 19, 2005 If a channel goes off and on at all its unlikely to be a triac or thyristor problem, its more likely to be in the timing circuits. SCRs pretty much fail short or open. Unfortunately, fixing these circuits is harder than replacing a dead output device, though to be honest, not too hard if you've got a schematic, a scope and passing familiarity with analogue electronics. An isolating transformer or RCD protection is also essential as you've really gotta work on these things live... Link to comment Share on other sites More sharing options...
JimWebber Posted October 19, 2005 Share Posted October 19, 2005 Hi Duntokin I'd definitly agree with Gareth, problem 2. does sound suspiciously like a fader problem. I'm always drumming into my class, look for the obvious weak points, ie fuses and the second most common are any kind of moving component. Problem 1. does indeed sound like a SCR problem, however there could be many more simpler faults, such as dry joints, broken cables, etc. Jim Link to comment Share on other sites More sharing options...
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