capacitors that look like glass diodes

[studley67]

was fault finding mildflames flash mpu.and found an open circuit diode.i thought.turns out is was c32 a 0.047 capacitor in an axial package.had printed on it 473 and thats all.it was glass,and looked like a small signal diode ie. a 1n914.so it was ok in the first place.WARNING to the novice  like me.lol.

also found alink to sys3-6 schematics here   http://tuukan.fliput.net/wms_en.html

[Homepin]

Yes, they were very common in most electronics around the time these machines were built.

The code 473 is assembled as follows:

4
+
7
+
3 x "0" (zeros)

makes = 47000

move the decimal place 6 to the left and you get

.047ufd

[studley67]

thanks mike,worked that out.

[studley67]

have u got any?

[ajlaird]

Should be able to replace with equivalent rated ceramic, I would have thought.

[Homepin]

completely NON ctitical in this application. Almost any small cap will work OK and generally with values between .01 and .1 will make no difference although .047 is a very common value so it will be easy to find in many different styles of cap.

I prefer the "MKT" type myself as they are regular in size and so they look neat on a finished board. Axial types like this are a bit harder to find these days. For the Bally MPU project I had to have a small run done in the capacitor factory of the common values used on the board as they were not available 'off the shelf'.