ca-810

Willy6

AK Subscriber
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I recently aquired a yamaha ca-810 that does not power up I currently have it dismantled and ready to work on. The left channel outputs are both shorted but the right channel outputs are still good.
Does anyone have a parts replacement list for this amp? Any help will be greatly appreciated.
 
I recently aquired a yamaha ca-810 that does not power up I currently have it dismantled and ready to work on. The left channel outputs are both shorted but the right channel outputs are still good.
Does anyone have a parts replacement list for this amp? Any help will be greatly appreciated.
Is this a fuse resistor?It reads O.L M ohms on my meter.20171116_024531.jpg
 
As a general precaution you should also check TR421,3 and D417
I plan on recapping and replacing any bad components and putting new multi turn trimmers in.What would be a good replacement for the fuse resistors? I'm counting eleven of them on the left and right channel main amp board
 
I plan on recapping and replacing any bad components and putting new multi turn trimmers in.What would be a good replacement for the fuse resistors? I'm counting eleven of them on the left and right channel main amp board
This transistor is shorted also stuck in the middle of some corrosive looking old glue.20171116_120056.jpg 20171116_120041.jpg
 
What would be a good replacement for the fuse resistors? I'm counting eleven of them on the left and right channel main amp board
You only need to replace those that have drifted out of spec, +20%? Replacement options are becoming scarce Yageo FRM25 (0.25W) and FRM50(0.5W) are at
Mouser in a reasonable value range. Remember, it's a fuse so don't up the wattage. I'd be reluctant to replace a FR with an ordinary metal film but sometimes there
is no choice. Mount FR's/metal films well above board.

The board looks ugly but will clean up ok. The CA-810 is supposed to be a nice sounding amp. Got a CA-800 and a CA-1000 both refurbished and sound good.
 
You should check if you have any of those polar tantalums in the phono and preamp. Nichicon KL or MKS being the preferred replacement
 
When you're thinking about replacing the trimmers, realize that the ones used originally had an adjustment slot on the bottom of the trimmer also. There are holes in the circuit board to make it easier to adjust them for setting bias, meters, and 25V rails.

Post #38 of my restoration thread shows the test points and trimmer holes in the CB.
 
Looks like you need to take a long bristled brush.I use and paint brush. And either compressed air or Vacuum cleaner to the boards component side.
 
I found these Panasonic 15000uf 80v caps in my arsenal they are 40mm around by 80mm tall and the originals are 12000uf 58v 40mm around and 70mm tall.20171116_193215.jpg
 
Im not sure yet but if i use them it wil be after i get everything else done and the unit put back together.
Are there any transistors in this amp that are known problem makers?If not i'll leave them alone and just replace the bad ones.
 
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