The analog I/O card in <T> of Q core was to be replaced. After the card was inserted and processor was reboot, the processor booted uptil A6 (rather than A7 which shows OK status). The jumper connections were checked and found to be okay. However, an anomaly was observed in the three pair of LEDs marked as CR25,CR26 and CR27 located at the bottom left corner of the circuit board. Two of the three pairs of LEDs were on(blinking), while in CR25, one of the two was off.

Does anybody know what do these three pair of LEDs indicate? or has anyone experienced same kind of problem while replacing analog I/O cards in any of the cores?

 

Which card in <T> are you referring to? Did you have to change any EEPROMS? If so, make certain that they are the correct ones. Also ensure that all connectors are in securely. Basics, i know, but this has been the most common causes of failing to attain A7 here.

Also, why was you changing the card in the first instance? Was the core at A7 prior to changing the card?

 

That was TCQA card in <T> core. Thanks for the reply. The problem was with EEPROM.

Referring to my first post, could you help me with one thing? The three pairs of LEDS on the TCQA card that work for diagnostic purposes, two of them were lit. In the third pair, one was lit, the other wasn't. What would that be referring to? Any idea?

 

Anyone has any info to share??

 

The search function of control.com is second to none on the World Wide Web for any similar application. There are several previous posts about the LEDs (LED bar graphs) of Mark V cards. The prevailing line of thought has been that the Mark V development engineers used the LED bargraphs for troubleshooting purposes during the development and refinement of the Mark V. As such, the indications of the LEDs changed almost with every PROM revision, and there seemed to be no internal GE standard that directed the development engineers to return the LED indications to any kind of standard indication.

From my experience, all the LED bargraphs should flash with the same frequency, and the LED bargraphs on similar cards in various cores should all flash the same sequence. If the TCQA in <T> flashes a different sequence than the other TCQA cards in <R> and <S>, then that card will probably be annunciating some Diag. Alarms and may be exhibiting undesired behavior. But, that seems to be about all we can determine from the LEDs: That if one card is flashing a different sequence than other similar cards in other cores, it will also likely be annunciating Diag. Alarms to alert the user to some problem.

If you haven't tried the control.com search function, you have been missing something. It handles multiple word search strings, which most other application search functions can't handle at all, or very poorly. As with searching the Internet with any search engine, you may have to try many different words and combinations of words to find exactly what you're looking for. Unfortunately, several people can observe exactly the same incident or occurrence and most will all describe it differently or ascribe it to different causes; that's just the nature of people and it does make searching more difficult. But, I usually find some very interesting information searching this way; sometimes, even if I find what I'm looking for on the first try, I'll try other combinations of words and terms and almost always find more or even better information.

 

Thanks!