Always give a newly aquired piece of gear the once over.
2010-06-03 by jabathaslut
It never ceases to amaze me how silly some people can be when it comes to their equipment. Yesterday I received an SDS800 which came with the warning 3 channels working one not. It was in nice cosmetic condition and the price was good, around $100US. Until I was injured in a work accident I have always professionally design or repaired electronic equipment. Whenever I approach a repair the first thing I do is a visual inspection, inside and out before even thinking of applying power. With this unit (as with many other repairs) I am glad I did. First I check the power lead for damage. Next I pop the fuse and check it and the holder. In this case it was fine. I removed the case screws (make sure the power cable is not plugged in!!) and checked around the rear of the fuse holder and where the mains cable enters the case. Once again I found the stupid action of someone (possible not the previous owner given its age) in where they have put a short length of wire across the 2 fuse holder connections thus negating the action of the mains fuse. I can not say too many times how dumb this is!! The fuse is there to act as a protection device!! , not for you or the household wiring but for the unit it is fitted to! In this case, the power supply showed distinct signs of overheating the cause of which was traced to a bad electrolytic cap across the supply on the main PCB. Actions like this can cause a device to overheat or cause disastrous damage to the circuitry. Overheating can lead to fire with obvious danger. Please take care when using a piece of gear you have recently taken ownership of. You new toy could turn out to not be what you expected!! BTW, the channel fault was a couple of fractured solder joints of the trigger circuit on the main board. It now sounds as good as it looks. Cheers Richard