I just got back from a multi-day event. During rehearsal on day 3, the GLD-80 surface went dead. We replaced the IEC cable and it worked for a while, but a couple hours later went dead again. A fist bang brought it back to life once more.
After surviving the next session, we opened up the surface to figure out what was going on in the power supply. It turned out that the power supply input fuse was the issue. There isn't a fuse holder in the power supply - the fuse is an axial-leaded thing that stands vertically, and one of the leads had apparently broken (the fuse itself was intact). I soldered a jumper wire across the fuse, and we were up and running.
It was interesting to see the internal construction of the GLD. I was a little surprised that it's a standard ATX power supply (with some custom lead lengths) with only +/- 5V and +/- 12V. Most mixers have higher voltage rails from the power supply - the GLD must do up conversion somewhere for the analog section. Also interesting (but not particularly surprising) is that the system is based on a small PC system board with various subsystems connected via USB cables.
I'm a little conflicted about leaving the fuse bypassed. It seems unlikely to me that a circumstance will arise during the life of the board where the fuse would blow short of a power supply failure; the solution being replacing the power supply. It seems then, that I can either spend a bunch of time dismantling the board and power supply again, finding the correct axial fuse, repairing, and re-assembling, or I can simply use it as is, and in the unlikely event that it dies in the future, just replace the power supply at that time.
Am I missing something? Is it likely that if the power supply would fail, it would do so in such a manner that the lack of an input fuse would cause the power supply to take out the rest of the mixer?
P.S. Allen & Heath - this is now the second power supply in my various GLD gear that has failed on me in less than 3 years (power supply in AR2412 died last year). I would really appreciate it if you would spend the extra $.08 or whatever it takes to put non-crap power supplies in your stuff. I love the functionality, but you guys could learn a few things from Yamaha in the reliability department.
After surviving the next session, we opened up the surface to figure out what was going on in the power supply. It turned out that the power supply input fuse was the issue. There isn't a fuse holder in the power supply - the fuse is an axial-leaded thing that stands vertically, and one of the leads had apparently broken (the fuse itself was intact). I soldered a jumper wire across the fuse, and we were up and running.
It was interesting to see the internal construction of the GLD. I was a little surprised that it's a standard ATX power supply (with some custom lead lengths) with only +/- 5V and +/- 12V. Most mixers have higher voltage rails from the power supply - the GLD must do up conversion somewhere for the analog section. Also interesting (but not particularly surprising) is that the system is based on a small PC system board with various subsystems connected via USB cables.
I'm a little conflicted about leaving the fuse bypassed. It seems unlikely to me that a circumstance will arise during the life of the board where the fuse would blow short of a power supply failure; the solution being replacing the power supply. It seems then, that I can either spend a bunch of time dismantling the board and power supply again, finding the correct axial fuse, repairing, and re-assembling, or I can simply use it as is, and in the unlikely event that it dies in the future, just replace the power supply at that time.
Am I missing something? Is it likely that if the power supply would fail, it would do so in such a manner that the lack of an input fuse would cause the power supply to take out the rest of the mixer?
P.S. Allen & Heath - this is now the second power supply in my various GLD gear that has failed on me in less than 3 years (power supply in AR2412 died last year). I would really appreciate it if you would spend the extra $.08 or whatever it takes to put non-crap power supplies in your stuff. I love the functionality, but you guys could learn a few things from Yamaha in the reliability department.