Preamble- I am somewhat newbie to electronics repairs. I know the basics and have fixed a few things in the past. I have limited experience fixing audio equipment.
I picked up a non working CA-610II and decided I would give it a go on repairing it.
When I got it I was told the output transistors were shot.
I opened it up and sure enough a pair of transistors on one side was missing along with a blown 5A main fuse.
I managed to find a set of factory ones and put them in.
I gave it a visual once over, put in a 5a fast blow and switched it on. About 1 second delay and pop goes the fuse. Back to the work bench. I tested a few things (PS caps mostly) but found the rectifier was toast. I replaced the rectifier and figured I was popping the fuse from that.
Put in another fuse and round 2....about 2 seconds after on I heard a small pop near transformer. But fuse didn't blow and everything seemed to be OK.
Checked voltage at output of transformer and seems good.
Music now plays, both channels are very distorted and doesn't seem to have much volume. Deoxit'ed all switches and pots. Distortion no matter which input, regardless of volume, speakers a or b both channels.
I started searching the forums thinking maybe it was biased wrong (understand the principle but not dure how to check it) and came across something someone mentioned in a post...and I think I may know what I did wrong and feeling a bit like an moron.....what does a mica insulator look like for the output transistors ....because I dont recall that.
I picked up a non working CA-610II and decided I would give it a go on repairing it.
When I got it I was told the output transistors were shot.
I opened it up and sure enough a pair of transistors on one side was missing along with a blown 5A main fuse.
I managed to find a set of factory ones and put them in.
I gave it a visual once over, put in a 5a fast blow and switched it on. About 1 second delay and pop goes the fuse. Back to the work bench. I tested a few things (PS caps mostly) but found the rectifier was toast. I replaced the rectifier and figured I was popping the fuse from that.
Put in another fuse and round 2....about 2 seconds after on I heard a small pop near transformer. But fuse didn't blow and everything seemed to be OK.
Checked voltage at output of transformer and seems good.
Music now plays, both channels are very distorted and doesn't seem to have much volume. Deoxit'ed all switches and pots. Distortion no matter which input, regardless of volume, speakers a or b both channels.
I started searching the forums thinking maybe it was biased wrong (understand the principle but not dure how to check it) and came across something someone mentioned in a post...and I think I may know what I did wrong and feeling a bit like an moron.....what does a mica insulator look like for the output transistors ....because I dont recall that.
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