Good afternoon.
THis one is driving me crazy... Output section keeps blowing output transistors. Soon as power is applied protection doesn't seem to want to latch. It just clicks in and out super fast then pop! I've replaced the drivers over and over with every new repair attempt. I don't believe they are the problem.
I have made the low voltage "jig". I'm pretty sure I can wire the ground to anywhere in this amps secondaries. They all appear to be wired together. None are separated, that I noticed.
I'm just not sure where to go from there. As far as "local and global feedback". It's my first time trying to use this. If anyone can walk me through it, would be greatly appreciated.
So, 2 things... how can I look at the drive signals coming from the output card to the transistors? What exactly are the differences between local and global feedback? I know the tutorial says a bit about it... but I'm just try to not cause much more damage. Been on this one for awhile. It really has me going in circles here.
Thanks
THis one is driving me crazy... Output section keeps blowing output transistors. Soon as power is applied protection doesn't seem to want to latch. It just clicks in and out super fast then pop! I've replaced the drivers over and over with every new repair attempt. I don't believe they are the problem.
I have made the low voltage "jig". I'm pretty sure I can wire the ground to anywhere in this amps secondaries. They all appear to be wired together. None are separated, that I noticed.
I'm just not sure where to go from there. As far as "local and global feedback". It's my first time trying to use this. If anyone can walk me through it, would be greatly appreciated.
So, 2 things... how can I look at the drive signals coming from the output card to the transistors? What exactly are the differences between local and global feedback? I know the tutorial says a bit about it... but I'm just try to not cause much more damage. Been on this one for awhile. It really has me going in circles here.
Thanks
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Email me your IP4 address and you can download the newest version. The last version has photos showing where to make connections for the local feedback resistor.
If it has the low voltage jig in it, it can't be that old.
Using the low votlage rails, you can use something like the IRFP064N for outputs until you find the problem.
If it has the low voltage jig in it, it can't be that old.
Using the low votlage rails, you can use something like the IRFP064N for outputs until you find the problem.
See also#5.
If the two secondary grounds are connected together for each transformer, they are likely all tied to the secondary ground. When you have series'd secondaries, you have one transformer (or one transformer for each power supply) with grounds tied together then the other secondary 'grounds' are separated and go to the output of the previous secondary winding.
If the two secondary grounds are connected together for each transformer, they are likely all tied to the secondary ground. When you have series'd secondaries, you have one transformer (or one transformer for each power supply) with grounds tied together then the other secondary 'grounds' are separated and go to the output of the previous secondary winding.
So after replacing all the output drivers again, plus the LM211, LM293, TL072 and replacing the IL393 on ps card with a LM393 amp seems to be working on low power with one 064N per bank in.
So, from here I should add in the rectifiers and gop to full power? Or should I check some other things. All of the banks seem to be making nice square waves with equal amplitude. With the low power jig in use.
So, from here I should add in the rectifiers and gop to full power? Or should I check some other things. All of the banks seem to be making nice square waves with equal amplitude. With the low power jig in use.
Try twisting/pushing/pulling on the inductors. You could also try heating them some and doing that again.
Push on the main and driver board to see if there may be an intermittent connection.
You could add a few turns at a time to increase the voltage slightly to see if anything changes. You have to stay below the breakdown voltage of the 064Ns. Bear in mind that if there is a fault at higher voltage, the limiting lamps may burn out but that would be an insignificant cost to find that there is a fault.
Push on the main and driver board to see if there may be an intermittent connection.
You could add a few turns at a time to increase the voltage slightly to see if anything changes. You have to stay below the breakdown voltage of the 064Ns. Bear in mind that if there is a fault at higher voltage, the limiting lamps may burn out but that would be an insignificant cost to find that there is a fault.
Ok. I couldn't find any problems on low power. Went back to full power. Shorted out all 4 low side fets I installed into amp. 1 per bank. Took out one IC. Replaced them all again. Here we go again.
The following pics are 1st high side gate, second low side gate, 3rd high side pin 3, 4th low side pin 2. I'm still stuck on this one. Scope is at 2v/d. Good news is the protection seems to be working properly after replacing the other IC's.
The following pics are 1st high side gate, second low side gate, 3rd high side pin 3, 4th low side pin 2. I'm still stuck on this one. Scope is at 2v/d. Good news is the protection seems to be working properly after replacing the other IC's.
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