[dusdau]

I have Marantz AV7005 prepro that is putting out a very, very low or no output from the front left channel periodically. It'll 'go out' anywhere from 10 minutes to a few days for what appears to be no reason.

It doesn't matter what source it is...blu-ray, CD player, internal tuner for HD radio, internal 'white noise' when adjusting channel levels...doesn't matter.

It's been in two service centers (one local in KC, other United Radio in NY) and neither could find an issue (United Radio fixed an HDMI jack, but that should be unrelated). United ran an 'extended bench test' for a week or so, and could find nothing.

Very frustrated. I have tested the speaker of course, all cables, power amp channel, etc. and it all leads back to a channel issue with the prepro. 'Testing' just consists of switching speakers, running interconnect to a different power amp channel, swapping cables etc. I reset the prepro several times with no luck. Also tried varying combos of leaving prepro on, leaving power amp on, the order I turn them on, with also no luck.

It will just starting working out of the blue, and will work fine for anywhere from 1/2 day to a couple weeks. Seems to have been happening more often recently, though.

It is coming back from United Radio soon with 'No Problem Found' (beside unrelated? HDMI jack), but I am really concerned the issue with rise up again.

Anyone have any ideas at all?? What the issue within the prepro could be? An issue not related to the prepro that I'm just missing for some reason? I bought at accessories4less.com as a refurb if that's important at all. I was very detailed in my description of the issue with United Radio.

This may be way out there...but we got cat for kids roughly seven months ago, and I don't believe there was an issue at any time before that. Cat periodically will get behind equipment for a minute or two. Fine cat hair dropping in vent possible cause?? Just trying to think of anything at all. Or maybe it's a DSP, logic board, etc. issue of some sort no one wants to acknowledge?

I will seriously send $50 to anyone who can concretely diagnose. If that's frowne upon in the forums, then take it as an illustration of my desperation!

Dustin


Read more: http://www.hometheatershack.com/for...lem-low-channel-level-help.html#ixzz2nNs1k3Rl

 

[rab-byte]

Dumb question. Have you tried smacking it? Could be a loose connection inside the amp. I have a bluray that's going out. The display and IR cuts out with deep bass hits (sub is close to equipment stack).

Bench tests simply run the unit for a period of time.

 

[dusdau]

Dumb question. Have you tried smacking it? Could be a loose connection inside the amp. I have a bluray that's going out. The display and IR cuts out with deep bass hits (sub is close to equipment stack).

Bench tests simply run the unit for a period of time.

I did try giving it a smack or two (or a few) to no avail. Hopefully it just comes back working full-time again with no issues (maybe whatever it was got 'fixed' during normal testing process at the center...spraying compressed air, deoxit, etc.)

I did advise them on the bench test to perhaps simulate an at-home environment and turn on and run for a while, switch it to 'standby' for a bit, etc. They kept if for an extra week after they first said it was done, but who knows what process took place over that week.

Dustin

 

[chaosngn]

I signed up just to let you know I have the same problem. It comes and goes. Sometimes it's very low with static, and sometimes it's normal. I've noticed that it's typically find when the unit has been off, but then after it's been on a while, it goes. This could be 5 minutes or 2 days.

So, it's not just your unit. If there are two of us having this exact same problem, there are more. Especially since it just happens to be the same channel with us both.

My gut tells me it's a faulty OpAmp

 

[dusdau]

I signed up just to let you know I have the same problem. It comes and goes. Sometimes it's very low with static, and sometimes it's normal. I've noticed that it's typically find when the unit has been off, but then after it's been on a while, it goes. This could be 5 minutes or 2 days.

So, it's not just your unit. If there are two of us having this exact same problem, there are more. Especially since it just happens to be the same channel with us both.

My gut tells me it's a faulty OpAmp

I've seen a few more comments out there also...in amazon reviews, another forum, etc. I ended up having to ship it off to United Audio to get repaired (under warranty thankfully). They diagnosed a bad HDMI input, and replaced it. When the ticket was opened, I could see the progress when I logged in at UA...'found bad HDMI', and I stressed to look for something else as an HDMI didn't seem in line with the issue.

That was all they found, and the unit was sent back. I have had NO issues since then, so who knows. The skeptic in me thinks it's a known issue, and they fix it without really divulging it is a unit wide problem. Anyhow, was gone for two weeks, and going on a year now with no problems.

Dustin