2220B problems

[Jailtime]

As you probably know, I'm recapping my 2220B. All went well until I got to the last part, recapping the P700 main amp and replacing the filter caps. After inspecting everything carefully, I fired it up. No caps exploded. Lights came on, relay clicked in, then lights out and main fuse blown. The fuses on the P800 power supply are OK. All caps were replaced with equal values, except the filters, which were upgraded to 8200uF/50V, the stock were 6800uF/35V. What happened?

 

[EchoWars]

I'm betting that you wired the 8200µf caps with the negative terminals tied together.

 

[Oerets]

No using a dim bulb ?


Barney

 

[Jailtime]

I'm betting that you wired the 8200µf caps with the negative terminals tied together.

This is very likely. There was a bar that tied the closest terminals together, I followed exactly how it was original. Except that the negative terminals are now tied together by that bar. I should have paid closer attention to the original setup. Now how to fix it? I know that I'm going to get rid of that damn bar, I don't like the weak connection. Thanks for the tip, EchoWars! :yes:

 

[EchoWars]

If we are to assume that:

(1) You have confirmed that you currently have the two negative posts tied together, and
(2) The red wires are for your positive supply, and the white are for the negative supply (this is YOUR job to confirm!)

then
(3) Desolder the cap with the white wire connected to it, and flip it around (negative terminal to the white wire, positive terminal to the buss bar that runs to the negative of the other cap).

Caps do NOT like being reversed like this. They can and do sometimes explode, and even when they don't, it's common for them to suffer permanent damage.

 

[Jailtime]

Thanks, EchoWars! Problem fixed. :thmbsp: Well, that was a learning experience, good thing it was on a not so nice 2220B.