Hi guys
I've got this amp here and everything seems to work great except I get no audio. Well, that's not strictly true, if I turn all the channels up and the volume on the amp to full I can hear the sound, albeit very, very quiet. The weird thing is that the front left channel seems the loudest with the others slightly quieter to various degrees.
It's not the headphone port thing since plugging in headphones gives the same result.
The problem is the same on phono input, HDMI and setup test tones too.
I've looked all over the boards and can't see anything obvious, I'm thinking the power and amp boards are ok but really need to know where to start looking. If anyone can offer some advice that would be fantastic.
I've a fair bit of electronics experience but it's mainly video and logic stuff.
I've got this amp here and everything seems to work great except I get no audio. Well, that's not strictly true, if I turn all the channels up and the volume on the amp to full I can hear the sound, albeit very, very quiet. The weird thing is that the front left channel seems the loudest with the others slightly quieter to various degrees.
It's not the headphone port thing since plugging in headphones gives the same result.
The problem is the same on phono input, HDMI and setup test tones too.
I've looked all over the boards and can't see anything obvious, I'm thinking the power and amp boards are ok but really need to know where to start looking. If anyone can offer some advice that would be fantastic.
I've a fair bit of electronics experience but it's mainly video and logic stuff.
Quick thought if it has them, although looking at web pictures I can't just see any... are if there are any "preamp out" to "power amp in" jumpers that are missing on the rear panel.
The switching and logic on all these type of AV receivers is pretty fearsome. You would need a service manual and scope and then trace the signal through and see if its possible to determine where things are going astray.
It is in any kind of user selectable mute mode ?
The switching and logic on all these type of AV receivers is pretty fearsome. You would need a service manual and scope and then trace the signal through and see if its possible to determine where things are going astray.
It is in any kind of user selectable mute mode ?
No jumpers on this amp sadly. I'm actually having trouble finding a legit website that carries the service manual. It seems like it's a bit of an oddball model that didn't take off or at least, it's reliable enough in general that people don't seem to have trouble with it. Lucky me! 🙄
I've reset it several times so no mute mode in effect.
Thanks for the input anyway.
I've reset it several times so no mute mode in effect.
Thanks for the input anyway.
You can try to play a source like the radio and plug the tape output to something to see if it sends line level ok. If it does it properly then I would look closer at the amp side of things. Check the output trannies and the rails to them. If it doesn't, check the voltages to any op amps on the input side as a place to start.
I had a Denon 4503 that I had to turn up to 0dB (sometimes +8dB; according to the Denon display for a really good track) to get it loud enough to push the speakers. For general loudish background listening I think I had it at -20 to -15dB.
A friend of mine had a Yamaha receiver/amp (not sure of the model but it was rated at a lower power than my Denon) and the same speakers and he only had to turn his up to -20dB to get (roughly) the same level of loudness as I had at 0dB.
It was a very subjective test, no doubt, but it was quite apparent that there was something wrong (or different) with the Denon.
I didn't get it checked out though so couldn't tell you what was it was.
A friend of mine had a Yamaha receiver/amp (not sure of the model but it was rated at a lower power than my Denon) and the same speakers and he only had to turn his up to -20dB to get (roughly) the same level of loudness as I had at 0dB.
It was a very subjective test, no doubt, but it was quite apparent that there was something wrong (or different) with the Denon.
I didn't get it checked out though so couldn't tell you what was it was.
Well since then I tried installing a pre amp board from my older avr-1906 as the pinout seemed correct and they looked like the same board but nope. After a few sparks from the SB/SL/C/FR (etc) plug on top and the main 7815 billowing smoke I've made matters much worse.
I've since replaced all of these transistors and a few of the resistors and diodes associated with them it did power on ok but now it's decided not to power on at all. Totally dead.
I replaced the main transformer, the smaller on board transformer, the power diodes, thermistor, power relay and a few other components in line with the 7815 to no avail. I've pulled every board and can't find any shorts so I'm at a loss now what to do. I hate to say it but I think it may be time for the skip unless anyone has any other ideas?
I've since replaced all of these transistors and a few of the resistors and diodes associated with them it did power on ok but now it's decided not to power on at all. Totally dead.
I replaced the main transformer, the smaller on board transformer, the power diodes, thermistor, power relay and a few other components in line with the 7815 to no avail. I've pulled every board and can't find any shorts so I'm at a loss now what to do. I hate to say it but I think it may be time for the skip unless anyone has any other ideas?
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