Yamaha M-60 predriver question

brutal

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Does anyone have a pic of the main board bottom to share?

I've one here and it doesn't make sense that it's even working unless the Schematic or main board image in the SM has a typo. The pre-driver pairs TR120/126 and TR119/125 are backwards from the board diagram in the SM, or they're labeled wrong on the schematic. I know I didn't switch them while repairing it, but it had been worked on before.
 
Does anyone have a pic of the main board bottom to share?

I've one here and it doesn't make sense that it's even working unless the Schematic or main board image in the SM has a typo. The pre-driver pairs TR120/126 and TR119/125 are backwards from the board diagram in the SM, or they're labeled wrong on the schematic. I know I didn't switch them while repairing it, but it had been worked on before.

Remember when looking at the diagram your looking at the foil side not component side.Sure you already know this ..But it needs to be said.:D
 
Ya, but the filter caps make for an easy reference and it's not a matter of up/down, it's a matter of left/right.

TR126 and TR125 are shown closest to the filter caps and indicated as SC3289[edit], yet the SA1306 are installed here. Looking again at the schematic, and the emitter of TR120 tied to the base of TR136 on both schem and board, it has to be a typo on the board diagram.
 
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Ya, but the filter caps make for an easy reference and it's not a matter of up/down, it's a matter of left/right.

TR126 and TR125 are shown closest to the filter caps and indicated as SC3298, yet the SA1306 are installed here. Looking again at the schematic, and the emitter of TR120 tied to the base of TR136 on both schem and board, it has to be a typo on the board diagram.

For future reference document/edit the typo.in your SM.
 
Anyone have any other version?

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Does anyone have a pic of the main board bottom to share?

I've one here and it doesn't make sense that it's even working unless the Schematic or main board image in the SM has a typo. The pre-driver pairs TR120/126 and TR119/125 are backwards from the board diagram in the SM, or they're labeled wrong on the schematic. I know I didn't switch them while repairing it, but it had been worked on before.
I have same question too,please anybody share picture of PCB
 
Look at all the transistors on the heatsink 2SC's(NPN) on one end and 2SA's (PNP) on the other. Place the 2SC (TR120 or 126 ) driver closest to the other 2SC's on the heatsink. And the 2SA (TR120 or 126) closest to the other 2SA's on the heatsink.
 
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