where is line voltage measured for "170 -phase loss L1-L2" error

machine saw overvoltage, now throws this error. all the voltages around the transformers seem ok, i tested optocouplers IC47, 48, and 49 on IO board per this info: Haas Mills > Alarm 17 Phase loss

im looking for the phase detection header but cant find it on my I-O board

bump. got the rebuilt drive back and getting same error

I haven't traced it on mine, but there probably isn't a phase header, it probably goes straight to the mocon. That test as referenced isn't really enough. You would be better off testing voltage at pin 4 of each IC, ( http://www.vishay.com/docs/83717/4n35x.pdf ) to see if it is pulled down. The one that reads high probably needs to be replaced. You could also check voltage between 1 and 2, should be somewhere around 1-2V. Don't shock yourself or get unhandy with the test leads. Also, it wouldn't hurt to trace down the wires and check the resistors that lead to these isolators, one of them could be bad.

I'd be tempted to just replace them all, its not that hard if you know how. What you do is, get a nice knippers like a CHP-170, and snip every pin so you can unsolder them out individually. Then get some good wire braid and flux, and suck the holes dry. If you have a .030 drill it helps as not all the holes will clean out perfectly.

thanks ill dig into it

ok heres what i have for AC V measurements on optocouplers. hard to tell from that crappy phone pic which is rotated but the writing starts on the upper right there (4N36/ISOCOM/1441L). from the polarity marking on the chip it looks like pins in the pic are

1 6
2 5
3 4


http://i.imgur.com/PN1Ie0w.png

hard to measure accurately with stray voltage, im guessing 32V and 15V are the only real measurements in that pic.

looks like to me IC47 and 48 are not getting signal at all and the resistors before them are cooked? which resistors would those be?

it seems that IC49 is getting a signal on the diode side but i test all 3 chips with my fluke and the diodes fail so all 3 chips are bad?

heres the DC volts (to ground)to pin 1 of each opto (unit powered up):

IC47:82V
IC48:0.2V
IC49:35V

DC voltage between pins 1 and 2 of each opto:
IC47:0.8V
IC48:<0.1V
IC49:-1.5V (negative polarity=blown?)

DC voltage to ground, pin 4 of each opto:
IC47:0.3V
IC48:<0.1V
IC49:<0.1V

You probably should read the voltage in AC mode as well, and measure the output between pins 4 and 5, rather than ground. Anyway though, why not just take it off and fix it? I'd trace the pins leading from 1 and 2 to find the filter circuit and replace those parts as well. Probably $20 in parts from mouser, and is probably a voltage divider, cap, and possibly diodes to rectify it. Or, send it to me, or buy one on ebay, or send it to one of the people that fix these on ebay.

If you do this yourself...

Check the pull up resistors that connect to pin 5, and check continuity from pin 5 to the wire harness.

Check resistance from pin 4 to ground.

Check all components in the voltage divider circuit, and continuity to incoming power.

pm sent friesen, thanks for the advice

All measurements should be DC. I doubt the isolators are being modulated.
Measure across pins 1&2, it should be between 0.9 and 1.7 volts, 1.3 volts nominal, (red lead on pin 1) when the output is activated (voltage across pins 5&4 is a couple volts at most).
What ground are you using? Chassis ground may not be the same as the DC ground.
Voltages you gave between pins 1&2 are too low according to the specification sheet. It could be the driving circuit or possibly these couplers are only active when phase loss occurs. Without more of the circuit it is hard to tell.
Pin 4 at ground - appears that the emitters of the 4n35x are grounded and the collectors pull to ground with signal.