whizzzy Posted March 27, 2009 Share Posted March 27, 2009 Hi, My son has an Ashdown MAG 300 that went pop the other night. I'm driving up to see him over the weekend in order to try and sort it out for him but would like to know from any BC members if they have any pointers in terms of what may be wrong and what spares to take with me. (Murphy's Law dictates that whatever spares I take will still be the wrong ones! ) The head is about 5 years old so is now well past any initial teething / burning in problems. When my son powered it up he said a blue flash came from behind the front panel. The head still switches on and the VU meter responds to input signals so it tends to indicate that the power supply section is still working but the output is as dead as a dodo. I must add that the amp has always been used with either one or two Ashdown cabinets so the output impedance matching is correct. I've been searching the forum and also t'internet and the only thing found relates to the mains transformers breaking down so that's not much help in this case. Any advice or information on the circuit design would be greatly appreciated also if anyone knows what devices are used in the output stage that would also be a big help. All the best Col Quote Link to comment Share on other sites More sharing options...
simon1964 Posted March 27, 2009 Share Posted March 27, 2009 Have you emailed Ashdown? My experience is that they are just about the most helpful manufacturer out there. Quote Link to comment Share on other sites More sharing options...
Clockworkwar Posted March 27, 2009 Share Posted March 27, 2009 Email ashdown, they will fix it if you can't. Quote Link to comment Share on other sites More sharing options...
whizzzy Posted March 27, 2009 Author Share Posted March 27, 2009 Thanks for the responses. I had already spoken to their service department and as you say they were very helpful. They suggested it may be one of the internal fuses but my experience is that if a fuse does blow with such force then it is indicative of other problems. It won't be a problem to repair the amp, I am just trying to go as best prepared as possible in order to avoid having to bring the amp home and thus shipping it back again. All the best, Col Quote Link to comment Share on other sites More sharing options...
Prosebass Posted March 27, 2009 Share Posted March 27, 2009 [quote name='whizzzy' post='447411' date='Mar 27 2009, 03:41 PM']Thanks for the responses. I had already spoken to their service department and as you say they were very helpful. They suggested it may be one of the internal fuses but my experience is that if a fuse does blow with such force then it is indicative of other problems. It won't be a problem to repair the amp, I am just trying to go as best prepared as possible in order to avoid having to bring the amp home and thus shipping it back again. All the best, Col[/quote] You may be lucky and it may just be a internal fuse (they do wear with use believe it or not) If the fuses blow immediately on replacing them the most likely culprits will be the output power transistors. Over time, again with use they can go short circuit and will overload the input hence blowing the fuses. The actual power transistors will cost about £3.00 each or less and its an easy job to replace them for someone qualified if you are proficient at such things. You may be able to get them from Maplins if there is one close by. If you do the job yourself don't forget the thermal paste. Paul Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted March 27, 2009 Share Posted March 27, 2009 The fuse can be fin to get at, if you get them at maplin's, double check you have the right ones, green pack for slow blowing. What cab was it? Check that also with a meter in case it is the source of the short, I found the out amp explodey way that 12" Bluelines can short via the wires inside the speaker touching. Quote Link to comment Share on other sites More sharing options...
whizzzy Posted March 28, 2009 Author Share Posted March 28, 2009 Thanks for the tips everyone. I'm just off up north to visit my son so I'll report back the findings tomorrow. All the best, Col Quote Link to comment Share on other sites More sharing options...
.gif.9ad672bb8b84505709f76b39c8c256ec.gif)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.