I need some help on measuring supply voltage to ic's.
I obtain the data sheets and know which pins are what.
Do i measure across the ic pin4 (-) to pin8 (+)
or ground to pin8 (+).

 

Which part is this in reference to? The supply pins are not always the same...

Measure ground versus the supply pins...

 

If I'm having problems, I usually measure right at the IC pins (both+ and -). I've seen problems where a broken PC trace removed ground from the IC.

 

Thank you for the responses.
I thought it would not matter which way, but billb3857 makes sense.

There are about 20 IC's on this metal detector unit.
All require 10v except 2 (7v and 5 v) according to data sheets
All read 9.9volts, except for 6 IC's
These 6 if done across IC, read 2.2volts
if done from ground to (+) pin, read 7.78volts

And oddly, if these 6 are measured from ground to the (-) pin
read 7.78volts.
All the rest measure- 0.0 volt

So, it looks like I have some tracing to do