27-10-2013, 12:03 PM
Yes, Rob, I've 'been there' too. My theory for those types of failures is that an odd high-voltage spike occurred that exceeded the resistor's voltage rating - pop! immediate O/C resistor. 
And as for "one of those inexplicable failures which occur from time to time", yes, I know what you mean: again, "been there". However, this is a somewhat different case to the example mentioned by Rob: everything here is at a much lower voltage. Of course, the good news is that you've found the fault and fixed it: hopefully. But what was the cause? There obviously was one. Is there a fault that is lying dormant and that will arise again - and cause the demise of that replacement resistor - or something else? (Yes, I've experienced that sort of trouble too.) You don't know if this will occur - and I'm not going to guess, either! But that's the rub with faults like this, isn't it? Perhaps the best thing to do now is to give the repaired item a substantial 'soak test': crossing fingers usually helps too!
Al. / Oct. 27, '13 //
And as for "one of those inexplicable failures which occur from time to time", yes, I know what you mean: again, "been there". However, this is a somewhat different case to the example mentioned by Rob: everything here is at a much lower voltage. Of course, the good news is that you've found the fault and fixed it: hopefully. But what was the cause? There obviously was one. Is there a fault that is lying dormant and that will arise again - and cause the demise of that replacement resistor - or something else? (Yes, I've experienced that sort of trouble too.) You don't know if this will occur - and I'm not going to guess, either! But that's the rub with faults like this, isn't it? Perhaps the best thing to do now is to give the repaired item a substantial 'soak test': crossing fingers usually helps too!
Al. / Oct. 27, '13 //
