caps for MC 2100, blows fuse

[nj pheonix]

Ideally you'd follow signal through both channels with a scope and look for the difference. I'm going to for now go on the assumption that the output modules are good ( which doesn't make it the case but you said you changed the ouput transistors ( did you check the emitter resistors?)
I don't know what's on your bench. You said you didn't change c309,310. You could try swapping them and see if problem changes channels. You've pretty much ruled out the 2 output boards if nothing changes when you swap them.

 

[c_dk]

I believe you are saying the issue does not change channels.

If the issue never changes channels, and since you are using a variable as your reference, what makes you think the right speaker does not have the issue.

 

[Hunted11]

I swapped the speakers also, no change. I did check the emitter resistors but I will check again. I wish I still had a scope. Unfortunately I am using my ears. The right channel is just flat, no low end at all. I was thinking of just swapping the output of the input board to see if is on the input or output side. Was inquiring to see if I was thinking correctly.

 

[c_dk]

You physically moved the speakers? If you just changed the wires and it stayed on the right.....or did switching the wires move the issue to the left.

Yes switching the output wires from the input/ power supply board is a good idea.

 

[Hunted11]

swapped the wires and the issue went to the other speaker. I will swap the output wires tomorrow as the bride and I are going out for a while. I will keep you posted.

 

[Hunted11]

Ok, I swapped the output from the input board and the problem swapped channels. Swapped back. Swapped c309 and c310. Problem swapped. Have a bad cap. I only have elecrolytics on hand. Have to order a couple of non polarized. Another wait, but happy that I have found my problem with all the great help here.

 

[nj pheonix]

You could use a film there.
Something like this
http://www.mouser.com/Search/m_Prod...GAEpiMZZMv1cc3ydrPrF0%2bjlB8SXIRuiBgDyxRCo7U=

 

[Hunted11]

Just an update, finally got a chance to order the rest of the caps. Replaced c309 and c310, it is up and running and sounds as good as new. A big thank you to all that have helped. I'm a happy Mac owner. Now to update the driver boards, but for now I am very pleased.

 

[nj pheonix]

Welcome to the club. Good work. What did you end up using for those?

 

[Hunted11]

I looked up the one you suggested, but the lead spacing was too wide. You did put me on the right track though, I ordered the same except the 100vdc version. Thanks again. It has been cranking all afternoon and it's barely warm.
I pretty much replaced all the caps, and the output transistors. I have not done a thing to this amp since I purchased it used in '73. It was Mac tested when I purchased it. It is too bad that a lot of the real good audio sales and service is long gone. We used to have 4 or 5 in the area in the day, now there isn't anyone close without driving and hour or more. Next project is the driver boards. I have all the parts except the heatsinks for the TO-39 transistors. I found them but it is up and running so it is not a priority.
I don't have much in the way of test equipment and my next failure is a Carver PM-350 that is oscillating. I found a shop in Conn. that is going to do the repairs. I will bring it to him next weekend.
Again, thank you

Bernie