I have an old school kicker ZX 750.1 amp that is not passing audio. I’ve been taking a hard look at the preamp board and there is a missing SMD capacitor C79 that goes across pins 1 and 3 of an A393F op amp.
I was wondering if anyone knew what belongs there or a safe value to use there to see if this is what is causing the amp to not pass audio. Also, feeding in a strong signal will cause the amp to cycle in and out of protection.
I have the area of interest circled in the attached photo.
Thanks,
David
I was wondering if anyone knew what belongs there or a safe value to use there to see if this is what is causing the amp to not pass audio. Also, feeding in a strong signal will cause the amp to cycle in and out of protection.
I have the area of interest circled in the attached photo.
Thanks,
David
Attachments
Never mind. That’s not the problem. I think the problem is on the main board with the predriver circuit. Looking into that now.
Post a pic of the Main board overall and one close up of the driver stage. This amp appears to be a 2008 or later.
Check the usual rail voltages and the nine pins on the preamp board. Also check the Vdc around U14-LM311 and waveforms on Pins 3,4 and 11 of the same chip. Post your results and screenshots.
Check the usual rail voltages and the nine pins on the preamp board. Also check the Vdc around U14-LM311 and waveforms on Pins 3,4 and 11 of the same chip. Post your results and screenshots.