so i have a esx signum se7000d that i been working and learning on. So after changing some bad parts the protect light is now solved however the output relay are not being engaged, sometime it engaged and would dissengage soon after. twisting or bending the pcb wouldnt do anything,then i recently came over this tread https://www.diyaudio.com/community/threads/crunch-class-d.395669/page-2 where they talked about shutdown pin2 on ir21844 which where internally supplied by 5v which i did not have after removing pin 2 from ir21844. before removing pin 2 it was about 2.5v referenced to terminal ground and after removing pin 2 it dropped to 8mv but had 5v at transistor which connects throught a resistor then to pin 2. after changing ir21844 i still had no 5v on pin 2 but somehow the amp engages the relay and stays on like normal with sound output.
why is there no 5v on pin 2 and i am worried that reconnecting the transistor to pin 2 that it will blow like all other ir21844.
why is there no 5v on pin 2 and i am worried that reconnecting the transistor to pin 2 that it will blow like all other ir21844.
Pin 2 is pulled up towards 5v internally. The external transistor is only used to pull that voltage towards the negative rail to shut the IC down during startup and shutdown muting... and protection.
The IC can become operative at near 2v on pin 2 but it's not normal for it to remain there. It should rise towards 5v. I've had ICs where I used too much heat and damaged the IC to act just as yours is doing. I'm not saying that that's your problem. It's only a possibility.
Which 'terminal ground' are you referring to?
The IC can become operative at near 2v on pin 2 but it's not normal for it to remain there. It should rise towards 5v. I've had ICs where I used too much heat and damaged the IC to act just as yours is doing. I'm not saying that that's your problem. It's only a possibility.
Which 'terminal ground' are you referring to?
Should i not me able to measure those 5v att pin 2 then? Iam only getting 8mv without the transistor on pin 2.
I mean Terminal ground as those main incoming 12v and ground . Reference on negative rail i got 105v and negative rail are about 102v.
The 21844 is referenced to the negative rail. There is nothing that applies or should be measured to ground.
If, with nothing connected to pin 2, it will not rise towards 5v Referenced to pin 3 or 5 which are connected to the negative rail), it's defective. There is a capacitor connected to pin 2. It could be defective.
If you're working with full rail voltage, it's risky to power up the amp without the initial mute delay connected. This only applies when the 21844 is functioning. I'd work with reduced rail voltage with this sort of problem.
If, with nothing connected to pin 2, it will not rise towards 5v Referenced to pin 3 or 5 which are connected to the negative rail), it's defective. There is a capacitor connected to pin 2. It could be defective.
If you're working with full rail voltage, it's risky to power up the amp without the initial mute delay connected. This only applies when the 21844 is functioning. I'd work with reduced rail voltage with this sort of problem.