Oscilloscope

An oscilloscope is one item which will (probably) have to be bought second hand as they are soooo extremely expensive!!! Depending on what you wish to use it on, the minimum specification will probably be a 20Mhz dual trace one. You should look for one at 50Mhz or more really, and one which has a Z input for displaying XY/vector games correctly (although they will still display on a normal dual trace scope, just you’ll see the retrace lines!)

Using a scope is very easy when you have the manual! You can set it up however you want and indeed it is a matter of taste for some of the settings. Also, slight adjustment will be necessary for different boards too. The easy way to set it up is to clip the probe to the test point for adjusting the standard controls like position and brightness. I like to set the time/division to 1Mhz but the X magnification to X10, the voltage to 0.2v/division, make sure the probe is set to X10 too. Now clip the ground point to ground on a board (!) and probe the crystal. If you have a 7Mhz crystal you should see seven ‘humps’ peaking at +5v which will be 2.5 divisions, phew! Note here that 1Mhz is way too high to use the test points on the scope itself, I use this setting for clock related problems and to check the equipment is set up correctly. Scopes are fabulously useful for checking for all manner of faults on boards, especially as I mentioned clock signal but also for colour/sync and sound related problems too. Hmmm… That pretty much covers nearly everything then!

You can also use a scope in conjunction with a logic pulser as its far easier to see what happens to a signal visually on a scope than using a logic probe.
There’s plenty of information on using scopes on the internet, I won’t go into depth because although its a useful tool - it really is a straight forward and easy one, I’ll cover a section on using a scope in the repair section.