Cr 800 right channel weak

Allisonholic

"Can you fix a Hi-Fi?'
I recently bought a CR 800 that the right channel is weak, it works, just weak. I've cleaned all the pots and switches and checked the grounds to the boards, everything checks out but the right channel is still weak.
 
I recently bought a CR 800 that the right channel is weak, it works, just weak. I've cleaned all the pots and switches and checked the grounds to the boards, everything checks out but the right channel is still weak.

Wiggle the coupler switch on the rear panel.And listen for the channels cutting in and out. Did you deox-it the coupler switch ?
 
I haven't checked the bias, I need to learn how to do that. Yes cleaned all switches with special attention to the function and balance and played around with the coupler switch. The guy I bought it from said it worked fine until one day it just got weak on the right channel
 
I fixed one once.

Found that is has fusistors (fusible resistors) in it that were bad.
My experience is that most fusistors I find are bad.

Study the service manual, locate the fusistors and test them.
Replace as necessary.

Maybe the problem.
 
I recently bought a CR 800 that the right channel is weak, it works, just weak. I've cleaned all the pots and switches and checked the grounds to the boards, everything checks out but the right channel is still weak.

You need to find out whether the preamp signal going to the main amp, is the same on both channels before making amplifier adjustments.
That's not difficult to determine since there are pre out and main in jacks. The coupling switch can separate them, allowing you to drive the main amp
with an external preamp source. Or you can use the pre outs to drive an external amp. This will help you isolate which area of the receiver you really need to
focus on.
 
Or switch to separate and use an RCA interconnect cable.
First the right way (L to L, R to R), to make sure things are still broke.
Then cross them (L to R, R to L).
 
Hooked up the iPod and the audio is equal from both channels, how ever I hooked it up it was the same so I guess it's the pre amp ?
 
Hooked up the iPod and the audio is equal from both channels, how ever I hooked it up it was the same so I guess it's the pre amp ?

Sounds like it. With a spare interconnect cable. Jumper the coupler switch ie. From "pre out" to "main in". This by-passes the coupler switch.
 
Here is a SM.
http://sportsbil.com/yamaha/cr-800-sm.pdf

You can check the offset and bias. But thats not going to remedy your problem.
If the coupler switch is not the issue. I still suspect you still have a dirty switch ( Function Switch). Almost impossible to thouroughly clean unless you disassemble it.
 
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Jumped the coupler switch with the same results, switched left and right problem went to the left side. In a thread from '09: http://www.audiokarma.org/forums/showthread.php?t=233642
someone else described the same problem and Merrylander suggested dropping the front and really blasting switches and pots with Deoxit so I'll give that a try. I'll see if I can PM that other guy see if he's still on and see if that cured his problem.
Thanks for the help
 
( Function Switch). Almost impossible to thouroughly clean and deox unless you disassemble it.
Without disassembly all bets are off.
 
I contacted Haileyburian who had the same symptoms on a cr 800 back in '09, he ended up taking to Marylander for repair. From his notes: "Traced all the way back to the multiplex output... Found an open capacitor between the last two transistors. Replaced..."

Unfortunately he didn't state which cap in his notes, I searched the service manual and I'm not even sure what the multplex is or where to find it. I know my limits when it comes to this kind of stuff and I have a tech I trust in Sacramento so I may just drop it off to him sometime
 
"Traced all the way back to the multiplex output... Found an open capacitor between the last two transistors. Replaced..."
That may be the case for issues with FM only.
 
I removed the red screws and dropped the front and really soaked all the switches especially the function switch, no improvement
 
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