Currently I’m fixing an Aiwa JX-505, all capacitors have been replaced, board cleaned and mechanism also cleaned The logic and control works fine,but I never get audio out of the headphone jack if I don’t do 2jumpers from the Dolby test pads to the audio amp. Seems like something is always muting the output Also replaced the amplifier IC and no change if you guys could give me a hand I’d be very thankful.
Two ways forward if you're not an expert at such electronics. One is to get the circuit diagrams and start looking for problems. The other is to get another one and do continuity or voltage comparisons.
aye im no expert electrical guy, no EE degrees here. looks like youre taking the current and just skipping some circuitry to mitigate the issue, that does narrow it down atleast tldr taking the output after dolby from tp101, passing it along to the alarm function output before amp and it completely avoids passing through IC3 (BBE chip). soo, sounds like IC3 is having issues or something along the line is *unless im reading through it wrong, this is how im visualizing it (assuming right channel is basically the same, only outlined L channel here) where you routed it to would be a little ways before R41 & R40, so itd be placed there ish on the circuit after R40. looks like a test point for the alarm function output circled some pin numbers and voltages to test for while its operating normally, id also check you clean out the switch for it. oh and kinda obvious now, but eh, Q7 and Q8 are labeled "Muting" fet transistors, maybe you should test those first now that i think of it... should edit this to begin with that but im lazy alarm output skips these while playback does not, they might just be your problem. not sure how or even if both could fail simultaneously though this is just a visualizer if you want it always a chance i made a mistake outlining circuit stuff and some ~50-60 year old electrical engineer with 25 years experience is gonna pop in to scream at me lol
Thanks for the advice I’ll look into it to see what I can come up with I also did checks with the schematics but I stopped for a while, currently fixing a D6C and then after than I’ll try the Aiwa once again
