CPU Not Going to Run Mode.

[Clay B. 1]

Have a bit of a puzzle here and am wondering if anybody else has seen this. I have a DL340 CPU in a Texas Insturment 10 slot base 305 series. The problem is that sometimes when you power the system down for any length of time the PLC will not go into run mode when power returns. At this time you can not go online with the CPU either. After awhile the CPU "magically" goes into run and everything is fine. Has anybody seen this before and if you have what did you find to be the issue.

[rlp122 4]

My guess would be that the base power supply is weak. This is pretty common on 305 bases that are over 12-15 years old. You can get a new base from Automationdirect.com.