[TinCanAlley]

Originally Posted by Username1

The test point may contain information that can be interpeted 2 different ways. With a scope, you will see the entire wave, peak to peak. Your volt meter depending on design will read whatever it is designed to read, some will read and store peak, some will read average, and most will read some type of R.M.S. this is a area under the curve calculus derived average voltage. The schematic often details how all readings are taken, and in some cases even details the type and model instrument used, (or equiv.) is often written. Your RMS voltage will depend on the quality of your meter, and the old expensive ones did say what frequency you can use it and expect a certain level of accuracy. I don't know what new ones say in the instructions...

It is important to be sure your test equipment is reading correctly, or you will be chasing something that does not exist. A calibrated ebay piece of equipment means squat unless you do a little checking to be sure it really is what it is....

If tp5 is not reading correctly, your problem may be right there, everything very near that point needs to be checked.

Funny thing about man made stuff.... Sometimes one model of something all have the same problem. So don't overlook something just because you got a replacement somewhere.... Go by what good troubleshooting skills are taking you towards.

The scope was calibrated by Teletek using N.I.S.T. standards and certified by them. I have a certificate of calibration. I also get a free calibration within one year, but they're up north and I don't know how practical it would be shipping to and from.

Okay, so how about this. I have tested it on DC and it reads correctly. For AC, can I check an outlet? I have a meter that plugs into the outlet and shows the voltage. It has an outlet to plug things in and measure wattage, etc. Can I use the scope to see if it reads the same AC voltage as the meter? Would also be interesting to see how noisy the AC line is.