Need Help!- 2T-3T I/O Problem

[tder1]

Hi There. Have no Output at Pin 37 on M2 Plug to Start Machine Hydraulics. Traced back and replaced first I.C. in Line but doesn't work. Anybody know which I.C.'s control Outputs? Bit in Diagnostics is working properly. Have about 20 of these Controls and no Schematics. Thanks in advance.

[guhl]

Make the photo of I/O card and put it out in your post or give the link
Photo should be in good quality so that we could make out the names of ICs

[Al_The_Man]

What was the output IC number that you replaced? What pin # was M2(37) connected to?
It may be a case of tracing the IC input back to the prior IC in line.
Al.

[jdeere4250]

I dont think I have board scematic. But the Maint. Man. says check. diag. 115/051 bits three, name of sig. is M18. on IC loc. G2-2 pin 5. I would say that if you have the diag changing state and the output is low , then reed relay problem. What EXACT cnc model ? 2or 3 a/b/c .... M or T ? I will dig some more for you.

[tder1]

Thanks. Mainboard A16B -1000-0010/08F 2T and 3T take the same Board. It came out of a 3TA but I'm diagnosing it in a 2TA. Star JNC-10
Diag. 51 bit3 changes high but nothing out of Connector M2 Pin 37.
OPON, Relay 17 to turn on Hydraulic Pump Motor Starter.
I traced and changed first I.C. SN75463P but don't know, can't determine, next in line? I'm sure it's not a Machine Side Problem, Relay ect. Replaced the Board with another and the Machine Started. Pics attached. Let me know if you need more info.

[guhl]

To satisfy yourself, with SN75463P problem or not, make the links between same input pins of different ICs SN75463P. For instance, as another IC choose the cool pump line. It's the most safe way (cool pump).
If it doesn't help, pay attention on SN74LS374, to which connection traced from SN75463P

[tder1]

Hi Guys, I replaced the SN74LS374. Didn't help. Not sure where to go from here. Will be difficult for me trace it further. Any suggestions?