bigmrg Posted April 21, 2015 Share Posted April 21, 2015 Good morning everyone. Posting for the first time as I can't find the solution anywhere else. I have a transcension 4 channel DMX dimmer that went from 0-100% in one go, blew a fuse and now each channel is stuck open. Even went the unit is powered off if it's connected to the mains and with fixtures attached, they're on full power. The dimmer just doesn't work. I know it's a long shot but has this happened to anyone else or have an idea is there any thing I can do before just buying another? Many thanks. Link to comment Share on other sites More sharing options...
timsabre Posted April 21, 2015 Share Posted April 21, 2015 Good morning everyone. Posting for the first time as I can't find the solution anywhere else. I have a transcension 4 channel DMX dimmer that went from 0-100% in one go, blew a fuse and now each channel is stuck open. Even went the unit is powered off if it's connected to the mains and with fixtures attached, they're on full power. The dimmer just doesn't work. I know it's a long shot but has this happened to anyone else or have an idea is there any thing I can do before just buying another? Many thanks. You will need to replace the triacs. Triacs commonly fail in a "shorted on" state.Depending on what caused this incident you might need to replace other parts too. This is not a difficult job but as it involves mains electricity there is a small risk of killing yourself, someone else and/or burning down your venue so you should only attempt the repair if you are competent to do so. Link to comment Share on other sites More sharing options...
paulears Posted April 21, 2015 Share Posted April 21, 2015 Pretty unusual for this to happen to all channels at the same time - were you doing something odd? Link to comment Share on other sites More sharing options...
timsabre Posted April 21, 2015 Share Posted April 21, 2015 Pretty unusual for this to happen to all channels at the same time - were you doing something odd? Yes that would be interesting to know. Accidental cross-phase connection or shorted load (on all channels simultaneously...)? Link to comment Share on other sites More sharing options...
boatman Posted April 21, 2015 Share Posted April 21, 2015 Unless you can do the job yourself, it's not worth repairing that dimmer pack as they are only around £75-£80 new. Even your local washing machine repair man (who is unlikely to have the right skills) will charge a minimum of £50 to open the case. Link to comment Share on other sites More sharing options...
bigmrg Posted April 21, 2015 Author Share Posted April 21, 2015 Unless you can do the job yourself, it's not worth repairing that dimmer pack as they are only around £75-£80 new. Even your local washing machine repair man (who is unlikely to have the right skills) will charge a minimum of £50 to open the case. Looks like I'll be buying a new one. It came with only 3 channels working but needed it that night so stuck with it. We use it for comedy so only need 2 channels. Nothing fancy. I blew them by accidentally connecting lamps while it was switched open and by going to 100% with two lamps on one channel. So it's my own fault. Everyday is indeed a school day. Very much appreciated for the replies. Link to comment Share on other sites More sharing options...
bigmrg Posted April 21, 2015 Author Share Posted April 21, 2015 We just an update, Google 'triacs' and eventually got to another post on here about them blowing in these dimmers found out what one looked like, took the dimmer apart and then got 3 from maplin.So for a tenner, some solder and a few burns got it going. Thanks guys, I'm over the moon! Link to comment Share on other sites More sharing options...
timsabre Posted April 21, 2015 Share Posted April 21, 2015 Great!They shouldn't have blown in the first place though in the situation you described. That's a bit mysterious. Link to comment Share on other sites More sharing options...
Don Allen Posted April 21, 2015 Share Posted April 21, 2015 Some manufacturers put in triacs rated at 16 amps for a 2400W channel. If they short out again and they may if a lamp ( or insert name here )blows, get a higher rating triac. 40A is a reliable rating to have in a 10A channel, it depends on how much space you have to fit the replacement triac into. An upgrade needs to have an insulated gate and the same gate sensitivity. Link to comment Share on other sites More sharing options...
Tomo Posted April 23, 2015 Share Posted April 23, 2015 Check the fuses. It may be that some helpful soul has replaced them with the wrong type - either slower blowing or higher current rating - and so are unable to protect the triac as they normally should. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.