JVC AX-R441 Weak Channel

[DNAgent]

Hi All,

So I picked up a JVC AX-R441 Stereo Integrated Amp at GW a few months ago and was disappointed to find the left channel very weak. Several of the lytics inside had gunk pooled around the bottom, so I replaced all of the large lytics in the unit (though there are quite a few very small ones I didn't mess with). No change in sound. :sigh:

Any pointers on where I should head next with troubleshooting this issue? I have a multi but no scope.

Thanks!
DNA

 

[ryuuoh]

Have you cleaned the controls?

 

[DNAgent]

Yep, DeOxit on everything. No dice. :worried:

 

[ryuuoh]

Does that unit have pre/main jumpers? You could check the pre amp and the main amp separately.

 

[DNAgent]

Nope, no pre-out on this one. Any other recommendations on where I could go from here?

 

[allsmith]

You might check the speaker relay,I had a reciever that one channel was acting up and i found the relay was oxidized,I was able to remove the cover on the relay and run a piece of 1500 grit sandpaper through the contacts.I used a Q-tip to push the contacts together while pulling the sandpaper through.I did not use deoxit on the contacts as some say you can ,some say not too,so i went dry and it fixed it right up

 

[mrflex65]

It wouldn't hurt to check for bad solder joints around "high heat" and surrounding area's (voltage reg's,power resistors,drivers,etc.) Especially in high mileage units.You'll see it as burned/discolored area's on top of the pcb/'s.Here's an extreme example of a JVC RX-705VTN...

 

[sonci]

I`d bet some money, its a cold solder joint, I had the same but also crackling on the weak channel.
as for the capacitors, jvc put a lot of glue around the base, so you probably just replaced good old capacitors...

 

[laidbacklark]

Picked up a mint looking unit at the local Goodwill (where the prices keep rising every week)for $30. Upon firing up, only one stereo channel worked, the other one was dead. Played around with the controls, switched speakers from A to B, switched inputs but no dice. Engaged the 7 band SEA equalizer and the single channel really came alive but not the other one - was feeling really bummed out. Then hit the Loudness switch. The dead channel crackled a bit, went dead again and a few seconds later came alive. And STAYED alive. Switched around all inputs again and no issues. Serious power on this unit and makes the small Pinnacle bookshelf set sing - this is the first receiver in my set that has made this bookshelf set come alive. So glad for the purchase. While mint with no damage, it’s very dusty, will give it all a full cleanup tomorrow. No hesitation, pick this unit up with confidence.

 

[jackfarrow]

Hi All,

So I picked up a JVC AX-R441 Stereo Integrated Amp at GW a few months ago and was disappointed to find the left channel very weak. Several of the lytics inside had gunk pooled around the bottom, so I replaced all of the large lytics in the unit (though there are quite a few very small ones I didn't mess with). No change in sound. :sigh:

Any pointers on where I should head next with troubleshooting this issue? I have a multi but no scope.

Thanks!
DNA

You were on the right track with the electrolytics, but the ones which are bad are small ones. Look at that little circuit board which sticks-up vertically off the main amp board. It's labeled "E11219-202". Near the top two corners of that circuit board are C711 and C712. These are 47MFD, 16V capacitors. They have gone open-circuit due to internal corrosion. No need to remove the old capacitors, just solder two new 47MFD capacitors across them on the solder side of the board. In the amp I repaired, the new capacitors brought back the weak channel and improved the bass response on both channels.

 

[jackfarrow]

Hi All,

So I picked up a JVC AX-R441 Stereo Integrated Amp at GW a few months ago and was disappointed to find the left channel very weak. Several of the lytics inside had gunk pooled around the bottom, so I replaced all of the large lytics in the unit (though there are quite a few very small ones I didn't mess with). No change in sound. :sigh:

Any pointers on where I should head next with troubleshooting this issue? I have a multi but no scope.

Thanks!
DNA

 

[jackfarrow]

You were on the right track with the electrolytics, but the ones which are bad are small ones. Look at that little circuit board which sticks-up vertically off the main amp board. It's labeled "E11219-202". Near the top two corners of that circuit board are C711 and C712. These are 47MFD, 16V capacitors. They have gone open-circuit due to internal corrosion. No need to remove the old capacitors, just solder two new 47MFD capacitors across them on the solder side of the board. In the amp I repaired, the new capacitors brought back the weak channel and improved the bass response on both channels.