Green-wire safety ground in the mains power cord is important for safety when using mains-powered electrical gear (including test equipment).
However, the green-wire safety ground should have nothing to do with the stability and functionality of your tesIs your scope not even able to trigger on its own test signal? (assuming it has a test signal since you did not identify the model).
No - it is Hitachi V-1050, it has a test output, cannot sync on it, ie no stable signal
it sounds more like the trigger circuit of the scope is broken
bummer
Sometimes I can get it to sync on a signal from the sig gen but it looks like a sweep function. For example one cycle will be on the left side and 5 cycles on the right.
Also assuming you are properly connecting the output of the function generator to the input of the scope.
With a BNC to BNC cable. If I play around with the controls a lot, sometimes I can get it to lock onto a square wave for awhile
You also did not mention how you are connecting this gear to your mains power source.
My wall outlet is 2 prong. I have an 3 prong extension cord going to the desk. I had to break off the ground plug so it would plug into the wall. I have a 3 prong outlet box plugged into the extension cord and the equipment plugged into the power strip.
For example: if you were using a modern, grounded power strip to power the signal generator and scope, that would connect the green-wire power grounds together, even if the power strip itself were NOT grounded because of the deficiencies of your mains wiring.
huh? my 3 prong power strip is connected to my wall via a 2 prong plug
I am sure now the scope is no good, I have 3 sources, 1. the built in 2. the Wavetek 145 3. a voltage ref with a square wave
time to dry off the tears and start saving for a new one
![Tongue :P](https://www.eevblog.com/forum/Smileys/default/tongue.gif)
glad to know it is not my wires