Marantz 2230 - Balance and distortion issue

[PF Sound]

I'll download a tone generator app.
By comparing AC voltages, would this give any clearer indication of bad components more so than comparing DC voltages?
Thanks,
Chris

It can..... variations in the relatively small AC signal voltages can give you a clue where a problem is. Start at the point of injection & measure the amplitude of the signal going into both channels (they likely won't be 100% equal going in so take note). Then just check & compare from point to point. If you come to a point where one voltage is different or is wavering then you're getting close.

 

[Chris __R]

It can..... variations in the relatively small AC signal voltages can give you a clue where a problem is. Start at the point of injection & measure the amplitude of the signal going into both channels (they likely won't be 100% equal going in so take note). Then just check & compare from point to point. If you come to a point where one voltage is different or is wavering then you're getting close.

Excellent - thanks!
Just to confirm - on that schematic I posted above, that would mean starting from J405 and J406 and work right to left, correct?

 

[PF Sound]

No, I'd start at J401/402 & work to the right. That should be the inputs to that board. If you're injecting your signals into the AUX, check your input levels there, then at J401/402 & see if they're still balanced. If so, work your way through the board. If not then the problem is before that. It has been a while since I've been in a Marantz so I don't remember the routing. This is a bit of a crapshoot, but sans O-scope it might be your best shot.

 

[ToxicTele]

If i remember correctly on my 2235 it was loaded with the 458 transistors. Those, IMO, are shotgun to replace. Not saying that's your problem but it certainly cleaned up my 2235.

 

[Chris __R]

No, I'd start at J401/402 & work to the right. That should be the inputs to that board. If you're injecting your signals into the AUX, check your input levels there, then at J401/402 & see if they're still balanced. If so, work your way through the board. If not then the problem is before that. It has been a while since I've been in a Marantz so I don't remember the routing. This is a bit of a crapshoot, but sans O-scope it might be your best shot.

Thanks! That makes sense. I'll hop on that this afternoon and see what I can find.

 

[Chris __R]

If i remember correctly on my 2235 it was loaded with the 458 transistors. Those, IMO, are shotgun to replace. Not saying that's your problem but it certainly cleaned up my 2235.

Thanks - I've already replaced the transistors on the P400 tone board thinking that was a logical solution. They were 2SC1000s and 2SA493s.
Now trying to hunt down the real culprit.

 

[Chris __R]

No, I'd start at J401/402 & work to the right. That should be the inputs to that board. If you're injecting your signals into the AUX, check your input levels there, then at J401/402 & see if they're still balanced. If so, work your way through the board. If not then the problem is before that. It has been a while since I've been in a Marantz so I don't remember the routing. This is a bit of a crapshoot, but sans O-scope it might be your best shot.

So - if I'm not crazy, it appears that the problem originates before the tone board.

I'm using an iPhone input at AUX with a 1000Hz tone with the iphone volume at max and the 2230 volume at 1/2.
Black MM lead is on chassis.

At the AUX inputs I measure 0.40v on both left and right.
At J402 (left channel) I measure 0.026v (seems low but what do I know?) Voltage increases and decreases with volume control.
At J401 (right) I measure 0.

Does this make sense?

 

[Chris __R]

So - if I'm not crazy, it appears that the problem originates before the tone board.

I'm using an iPhone input at AUX with a 1000Hz tone with the iphone volume at max and the 2230 volume at 1/2.
Black MM lead is on chassis.

At the AUX inputs I measure 0.40v on both left and right.
At J402 (left channel) I measure 0.026v (seems low but what do I know?) Voltage increases and decreases with volume control.
At J401 (right) I measure 0.

Does this make sense?

It actually doesn’t make sense - I realized the balance was turned all the way to the left……..
Beginning again….