[china]

Hello Everyone,

  I do not know if this right circle or forum to post this, if not, please post to the correct one!!!

  I have a Krell Showcase 5 amplifier that has discolorations on the top of amplifier case..from being in a enclosed equipment rack........and I would think that the discolorations would be from heat built up.

  I would like to know if there is a way to remove the discolorations????

  I have checked online for products that CLAIM to be able to do this......but untill proven......I remain sceptable.

  Also, would this cause the amplifier to not work properly or within the specifications.
  To my ears there is no problem or concerns........but, I am curious, IF, this could be a future prooblem.   

  Since I have been told that heat is not the friend of electronics!!!!
 
  My home phone number is (937) 732-8557 and my email address is ralphlomaxmansfield@yahoo.com

 
  As always, all the best. 


China

[FullRangeMan]

It seems that the finish is eroding and disappearing, I think it is impossible to restore it, except by sanding and painting again (or anodizing again if anodized).

P.S.> I would like to know if you had success in restore it.
Regards

[srb]

Discoloration of anodized aluminum amplifier casework (and heatsinks) is usually more seen with black anodized finishes, but I believe that the Krell Showcase series is silver only?

In any case, anodized aluminum discoloration is usually attributed to heat or UV exposure.  As you said the amplifier was in an enclosed cabinet, and you don't have discoloration on the aluminum sides, it seems like heat was the probable cause.

How hot is the top of the amplifier when operating?  The most vulnerable parts are the electrolytic capacitors whose life expectancy can be cut in half with each 10 degree C increase in temperature.  If you think temperatures are elevated in your enclosed cabinet you might considering using one or more low speed computer type fans for ventillation.

I would also be skeptical that a chemical product would restore the finish.  Most restoration procedures start with removing the oxidized layer with non-scratching abrasive cleaner (like Bon Ami) and a Scotchbrite type pad.  I would expect that even if you were able to "restore" the finish to a more acceptable condition, that you would no longer have a color or finish match to the existing sides and front panel.

If you're not trying to match other Krell Showcase components, perhaps a paint job would be the easiest and best looking solution.

Steve

[weitrhino]

And never clean anodized aluminum with a Windex-type glass cleaner.  This is known to cause a purplish discoloration.