There is no room for guesswork in electronics. If you can't explain everything in that schematic diagram find somebody else to do it.
If you don't have a schematic and better yet a sevice manual don't even try to do the surgery. Some little detail may not be obvious to the untrained eye which may cause you grief.
If you don't have a schematic and better yet a sevice manual don't even try to do the surgery. Some little detail may not be obvious to the untrained eye which may cause you grief.