have this b2 sld5k in that keeps blowing the power caps amp performs as it should after a week it'll blow 2 or 3 power caps
If this is for a previous repair thread, post a link. Also note that it's not necessary to start a new thread for the same amp repair. It's better to have all posts inline.
theres been no reply to this thread so i figured if i comment on it, it wiil move to the top of the list
I don't know what the amp is. Post a photo of the inside of the amp showing the drive circuit for the audio section.
Does the rail voltage increase as you drive signal into the amp?
Check at the output of every rectifier.
Do the same caps blow every time?
Are all of the caps on the same rail?
Check at the output of every rectifier.
Do the same caps blow every time?
Are all of the caps on the same rail?
Its blown caps on both rails, output on each rectifier is the same, positive and negative voltage. The amp blew caps on turn on with no signal in. Voltage increases with input
Have you confirmed that the drive signal to all outputs is as it should be?
I don't think that the following is risky but I haven't done it enough to know definitively.
Pin 2 of the 21844 is the shutdown pin. There is often a capacitor connected between pins 2 and 5 (negative rail). Connecting a jumper across that capacitor (or between pins 2 and 5) will shut down the ICs individually (on other similar boards, I haven't tried it with the board you have). Shutting down each IC (one at a time) may help you to determine if one half of the amp is causing the problem.
If you do this, monitor both the positive and negative rails to see if either or both are increasing to above the swing on the input to the rectifiers.
I don't think that the following is risky but I haven't done it enough to know definitively.
Pin 2 of the 21844 is the shutdown pin. There is often a capacitor connected between pins 2 and 5 (negative rail). Connecting a jumper across that capacitor (or between pins 2 and 5) will shut down the ICs individually (on other similar boards, I haven't tried it with the board you have). Shutting down each IC (one at a time) may help you to determine if one half of the amp is causing the problem.
If you do this, monitor both the positive and negative rails to see if either or both are increasing to above the swing on the input to the rectifiers.
ok so i have done what you have suggested, seems that the negative rail swings higher when either ir21844 is shutdown.
i have a new driver board which i have fitted but the amp still swings higher on the negative rail. could it be 1 of the opto's? and what would the 2 pots do?
i have a new driver board which i have fitted but the amp still swings higher on the negative rail. could it be 1 of the opto's? and what would the 2 pots do?
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Someone brought a similar amp in for repair. If they OK the estimate, I'll repair it and let you know what the pots are for.
Did you disable the 2 ICs individually to see if one or the other was causing the rail to increase?
Did you disable the 2 ICs individually to see if one or the other was causing the rail to increase?
I got the OK but it will be a couple of days before I can start on it. I have to undo some of the previous work that was done to it before I got it so it's going to be a bit more time consuming than a normal repair.
Perry have you repaired the similar amp that you had come in? I still havent gotten any further with this amp
I'm in the process of undoing a lot of the mess made by the previous tech. I'll try to get it back up and running tonight.
Me too!
Seems to be that this series amps are defective because i've tried in past to change all the rail caps thinking that the original caps are too cheap replacing it with a good nichicon product, but in few days the owner has the same problem.
I've talking about of this "problem" with ZENON CEO, (Mr. Frank) and he sais that a test that i can do is increasing a TANTALUM CAP on the PS driver board that manage the SOFT START at the start of the amp (he says that increasing this value, maybe i can solve the "problem") but i dont think.
He also says that this is the first time he hear of this problem on this particular model (NC5KSPL) produced for very large number of brand all over the world.
But really, this is a common problem on all the serie, because i've problem also on the bigger models that use "FANGZE" capacitors and use same chipset configuration (PS + AUDIO driver board), generally "ZNCM".
You can find a particular NC5KSPL in this video:
ZENON NC5KSPL - potenza reale [RESISTIVE LOAD @2OHM] - YouTube
As you can see, there are problems in RAIL CAPS or RAIL stabilization, because my signal become clip first in a semiwave and so in the other semiwave, due to the imminent failure of the rail caps.
Furthermore, seems to be that this "problem" occur only when the amp is mounted in a car, with the engine on (running alternator) and specially with a very low or totally zero volume.
Seems to be that this series amps are defective because i've tried in past to change all the rail caps thinking that the original caps are too cheap replacing it with a good nichicon product, but in few days the owner has the same problem.
I've talking about of this "problem" with ZENON CEO, (Mr. Frank) and he sais that a test that i can do is increasing a TANTALUM CAP on the PS driver board that manage the SOFT START at the start of the amp (he says that increasing this value, maybe i can solve the "problem") but i dont think.
He also says that this is the first time he hear of this problem on this particular model (NC5KSPL) produced for very large number of brand all over the world.
But really, this is a common problem on all the serie, because i've problem also on the bigger models that use "FANGZE" capacitors and use same chipset configuration (PS + AUDIO driver board), generally "ZNCM".
You can find a particular NC5KSPL in this video:
ZENON NC5KSPL - potenza reale [RESISTIVE LOAD @2OHM] - YouTube
As you can see, there are problems in RAIL CAPS or RAIL stabilization, because my signal become clip first in a semiwave and so in the other semiwave, due to the imminent failure of the rail caps.
Furthermore, seems to be that this "problem" occur only when the amp is mounted in a car, with the engine on (running alternator) and specially with a very low or totally zero volume.