I know these very well and all the other standalone variants... I won't spoil the fun though, watching with interest to see the process and culprit.... 😊
Coincidentally I returned one of these this week to its owner, having repaired it after it was dragged off a low table when powered up. Although there's plenty of space inside them to work in, the weight and sheer number of screws is enough to make one swear. The original fault caused by the hard landing was one of the capacitors blew (along with the main fuse), but someone else who attempted to repair it shorted the inner sheet metal shield to one of the main heatsinks - which are live when the unit is running - which blew up some of the semiconductors attached to the heatsink. Dynacord cannot supply replacements for at least some of the semiconductors, and they are universally obsolete and thus not available. Finding suitable replacements takes a while, but it was a satisfying fix. Very helpful that the schematics are available.
I love the way you talk your way through understanding how everything is supposed to work. I often wonder if you still do it the same way when you are not making a video? Or do you just dive in and wing it a bit? Great work!
Hi there, always enjoy your videos, the powermate mk2 are the best of the best, have one myself excellent sound quality and power, theres some TO92 package transistors near to the left fan which are the time delay and protection circuits etc... the last fault ive come across stuck in protect mode is one of them transistors was leaky, cant remember which one though but have a look in that area, hope it helps, look forward to the part 2
Having watched all of the video now, there are a couple of things I noticed. There should be a plastic shroud on each fan, to stop the escape of cooling air from where it should go, which is down the length of the main heatsinks, the other thing is a bit odd, though maybe related to the protection fault - on switch-on, the fans should ramp up, then after a couple of seconds stop again, only coming back on when there is enough heat to call for forced cooling. Interested to see what develops 👍
For mixers and some all-in-one PA mixer amplifiers (e.g. Bose L1 classic) - should charge the customer by the screw and fixing! Sooooooooo many of them!
I got a lot of information from the videos of your RUclips channel and it is very helpful for me, Is there a possibility of contacting you so that I can get information about other problems in the future?
Alternatively you could have chosen to investigate the problem the customer brought it in for, and the mixer was also telling you what was wrong. By doing very basic checks as you did then go and find out if the problem is the protect circuit itself is faulty or its telling you the truth and there really is DC on the outputs. When and LED shows a fault condition (customer is paying hourly) go investigate the fault. You haven't even explained to the viewers what "PROTECT" is !.....IMHO
@andymouse That's a good point.... but I'm sure he's explained what he's going to do to the customer and will charge appropriately. These are interesting amps to repair and can lead you a merry dance on many occasions even when you've identified the area that the fault is in so even though I've worked on many of these I'll still enjoy watching this.... 👍
@@johnnybravo505 I agree ! as long as the customer is aware that the video ' took the coast road ! ' and he isn't being charged by the hour ! because he isn't paying to watch somebody check a fuse. You could argue that if a video is made from the repair then no charge :)
I know these very well and all the other standalone variants... I won't spoil the fun though, watching with interest to see the process and culprit.... 😊
Heya, love the way you trouble shoot these kinds of faults can't wait for P2
It's the journey that is interesting, the destination is a bonus.
Exelente sus videos, gracia y saludos desde Cuba.
Coincidentally I returned one of these this week to its owner, having repaired it after it was dragged off a low table when powered up. Although there's plenty of space inside them to work in, the weight and sheer number of screws is enough to make one swear. The original fault caused by the hard landing was one of the capacitors blew (along with the main fuse), but someone else who attempted to repair it shorted the inner sheet metal shield to one of the main heatsinks - which are live when the unit is running - which blew up some of the semiconductors attached to the heatsink. Dynacord cannot supply replacements for at least some of the semiconductors, and they are universally obsolete and thus not available. Finding suitable replacements takes a while, but it was a satisfying fix. Very helpful that the schematics are available.
I love the way you talk your way through understanding how everything is supposed to work. I often wonder if you still do it the same way when you are not making a video? Or do you just dive in and wing it a bit? Great work!
Hi there, always enjoy your videos, the powermate mk2 are the best of the best, have one myself excellent sound quality and power, theres some TO92 package transistors near to the left fan which are the time delay and protection circuits etc... the last fault ive come across stuck in protect mode is one of them transistors was leaky, cant remember which one though but have a look in that area, hope it helps, look forward to the part 2
Having watched all of the video now, there are a couple of things I noticed. There should be a plastic shroud on each fan, to stop the escape of cooling air from where it should go, which is down the length of the main heatsinks, the other thing is a bit odd, though maybe related to the protection fault - on switch-on, the fans should ramp up, then after a couple of seconds stop again, only coming back on when there is enough heat to call for forced cooling. Interested to see what develops 👍
For mixers and some all-in-one PA mixer amplifiers (e.g. Bose L1 classic) - should charge the customer by the screw and fixing! Sooooooooo many of them!
Good God, those are some beefy components!!! that transformer is MASSIVE
I got a lot of information from the videos of your RUclips channel and it is very helpful for me, Is there a possibility of contacting you so that I can get information about other problems in the future?
I’m thinking a high value resistor when that positive line was not discharging, after turning off.
Alternatively you could have chosen to investigate the problem the customer brought it in for, and the mixer was also telling you what was wrong. By doing very basic checks as you did then go and find out if the problem is the protect circuit itself is faulty or its telling you the truth and there really is DC on the outputs. When and LED shows a fault condition (customer is paying hourly) go investigate the fault. You haven't even explained to the viewers what "PROTECT" is !.....IMHO
The intro is basically for people like you.
Go back and listen to it maybe you might comeback to delete what you commented above.
@@AyansolaAfolabi :)
@andymouse That's a good point.... but I'm sure he's explained what he's going to do to the customer and will charge appropriately. These are interesting amps to repair and can lead you a merry dance on many occasions even when you've identified the area that the fault is in so even though I've worked on many of these I'll still enjoy watching this.... 👍
🤫
@@johnnybravo505 I agree ! as long as the customer is aware that the video ' took the coast road ! ' and he isn't being charged by the hour ! because he isn't paying to watch somebody check a fuse. You could argue that if a video is made from the repair then no charge :)