i am working on an ESX Signum SE 3500D. 2 outputs were shorted.
i replaced them and also the 21844 driver ic.i removed the rectifiers for carefully
troubleshooting.
i drive an audio-signal into the RCAs and measure the signals on pin 7 of the 211( photo 1)
on pin 1 of the 21844 (photo 2)
pay attention to the volt setting of the scope.
the 21844 reads 12v between pin 5 and 7 but it produces no pulses on pin 6
What else can I do?
i replaced them and also the 21844 driver ic.i removed the rectifiers for carefully
troubleshooting.
i drive an audio-signal into the RCAs and measure the signals on pin 7 of the 211( photo 1)
on pin 1 of the 21844 (photo 2)
pay attention to the volt setting of the scope.
the 21844 reads 12v between pin 5 and 7 but it produces no pulses on pin 6
What else can I do?
Attachments
No. It needs to be over approximately 2.25v to enable the output.
The drive to pin 1, you may have to have some negative rail voltage for the level shifting transistor to be able to develop a drive signal. If you don't want to connect the rectifiers, you can connect an isolated power supply across the negative rail caps. I've never tried it but a 9v battery may be enough for a quick check.
The drive to pin 1, you may have to have some negative rail voltage for the level shifting transistor to be able to develop a drive signal. If you don't want to connect the rectifiers, you can connect an isolated power supply across the negative rail caps. I've never tried it but a 9v battery may be enough for a quick check.
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