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Re: 2445a power supply repair

 

In your position, I would change all of the aluminum electrolytic
capacitors except maybe for the input capacitors which are less likely
to be worn out. The output capacitors for the switching power supply
are usually the first to fail.

The electrolyte is acidic (boric acid?) and water soluble so cleaning
the area using a damp swab should be sufficient. I might use window
cleaner which has ammonia in it since this will neutralize any acid
and then follow up with clean water. I would not soak the entire
board to clean it.

On Sun, 27 Mar 2016 22:59:56 +0000 (UTC), you wrote:

Hello, David,

Thank you for answering. Yes, I do have a few other scopes, but before I've started the real debugging, I've noticed that the aluminum caps had a high leakage current.When I've unsoldered them, they literally leaked out!!! The epoxy gasket cracked and electrolyte was spilled to the center of the board. Fortunately no corrosion yet. The scope doesn't have many hours clocked. Just old. All the other caps seem to be dryed out, but these 6 caps: four 250uF and two 180uF are dead. Before going any further I've ordered @ Digikey the new caps for the power supply.
I'll keep you posted once the caps are installed.
Thank you,
Maxim
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