Post by platinumsteel on Jun 11, 2023 19:29:35 GMT -5
Hi guys hope you all doing fine. I have an issue with a Onkyo Receiver HT-R390 that is not giving me any sound output at all.Nothing tru any of the speakers.I tried different modes different inputs like HDMI and all the analog inputs and just no audio tru the speakers and also nothing tru the headphones output..It belongs to my uncle who said it just stopped giving out sound one day.All of the controls and dials function and i also see all the DSP and different sound modes on the display.It initially came with no audio/video outputs tru the HDMI which i repaired by changing the 5 capacitors that is responsible for the video.learnt this from a youtube guy doing the swapping of the caps and now i have video really appreciate that tutorial he did. But still no audio.This unit doesn't have the BGA Chip that needs reflowing .This one has the kinda DSP chip pins resembling a super IO for labtops.lol.. I really don't want to give up on it because i really want to start repairing amplifiers and devices like these so that i can be an all rounder when it comes to repair and not just labtops and phone repair.
I did a lot of research trying to solve this problem.So far i have heard that there are some muting transistors that sometimes go bad and ''MUTE'' the sound.I measured voltage on "AMUT" or "SBMUT" and i had 5 volts on those pins.I read somewhere that once there is voltage on those pins AMUT and SBMUT it will mute the audio.it is a signal that comes from the Microprocessor.So i removed some of those transistors thinking just in case those transistors might be bad.But moved them out and still no audio.And now i have 0 volts on SBMUT but still 4 volts or so on AMUT. So am not sure what to do at this point.My last hope this week is to build what u call an Signal Audio tracer so that i can use it to trace the audio coming out from the beginning and see where it stops.Hoping you guys here with your experience can hopefully guide me in the right direction and give me some pointers on things to check. thanks
I did a lot of research trying to solve this problem.So far i have heard that there are some muting transistors that sometimes go bad and ''MUTE'' the sound.I measured voltage on "AMUT" or "SBMUT" and i had 5 volts on those pins.I read somewhere that once there is voltage on those pins AMUT and SBMUT it will mute the audio.it is a signal that comes from the Microprocessor.So i removed some of those transistors thinking just in case those transistors might be bad.But moved them out and still no audio.And now i have 0 volts on SBMUT but still 4 volts or so on AMUT. So am not sure what to do at this point.My last hope this week is to build what u call an Signal Audio tracer so that i can use it to trace the audio coming out from the beginning and see where it stops.Hoping you guys here with your experience can hopefully guide me in the right direction and give me some pointers on things to check. thanks
i have uploaded a copy of the schematic for this model via my google drive.its about 10mb which exceeds the forum limit.
