square capacitors with dots
 

has anyone found these type of caps to be bad?

They aren't mica. Probably paper in a plastic shell. I routinely replace them, since many are bad.

Terry,

For the color code on caps, take a look at this page:

http://www.pmel.org/HandBook/HBpage26.htm


Chuck

caps again
 

thanks guys,i guess i have never seen this type of "paper" capacitor,i always thought maybe they were mica and are suppose to be "high reliability"

As described in the above link for determining value, they are of the mica type:

MOLDED MICA CAPACITORS: This was once a very popular type, rectangular with dots and arrow or similar directional indicator. Standard color code applies.

Terry,

I restored a Magnavox 1947 radio/record player console and while re-capping left these alone as I thought they were mica and were more or less bulletproof. They were exactly the same type caps as you pictured above. A while after returning this radio to almost daily use (I really like it) there was a smoke episode. One of thes caps literally split open letting the smoke out. It was one of a pair, each connected from opposite sides of the AC line to the chassis.

Rob

PS: Come to think about it, both of 'em shorted and split from the fault current. Where they were, one going short would have caused a hot chassis but not smoke.

Micamold
 

The caps with "Micamold" written on them are junk!

Philco used a lot of them in their TV's and they are always leaky or dead shorted.

Eric

micamold caps
 

well,this is interesting,i have been replacing them in this porthole chassis with orange drop type .05@600v.. hope it is safe!
terry
BTW I posted a pic (in swap area)of things that who ever wants them can have but pay for shipping,of the items are a couple of speakers,the one 10" one is good also but from a 1949 console that i can't remmeber the brand,also one of those odd shape preditca speakers.