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Home Forums What Caps to Recap Classic II? — #4 What Caps to Recap Classic II? — #4
Post #4 by Elfen
Source ForumWhat Caps to Recap Classic II? — #4
CategoryHardware
Post DateFri, 26 Dec 2014 - 07:14
Original URLhttps://68kmla.org/bb/threads/what-caps-to-recap-classic-ii.892/
Post
How ever it is done, or why it is done, you should get the caps with the right values on it.

A cap works something like a switch that you switch on and off constantly but at a much faster rate than you ever can. This creates a frequency within the circuit which is measured in Farads (microfarads, nanafarads and picofarads - microfarads - µf - being the main one of concern here). It is this frequency that determines the height and width of the video on the screen. Put in a different farad value into the circuit, and the height or width of the screen changes. So the farad values need to be the same in the circuit. The Voltage rating is how much the cap can handle. This can be changed to a higher value to make the circuit physically stronger. One of the caps on the Analog board is in the 1000 volt range, this one cap is connected to the high voltage transformer. This one cap is dangerous as it can hold that much power and the reason why working with the analog board can kill you. In replacing this one cap, short out its pins first before desoldering it. A screw driver across the two cap pins is enough to discharge it.

There are other caps on the board that charge up the high voltage transformer, that is why you discharge the transformer.

Since I seen your work, I think you will do well in getting the Classic II recapped nicely. Just take your time with it and get the right cap µf values for it, though you can use higher voltage ratings.

mp.ls