Allen Bradley 5/04 fault 1747-L542

Hello everyone,

I am having issues with a 5/04, it started a few weeks ago, if the CPU is powered off then it has issues rebooting, I have found a few things on one of Mickey's post HERE

Can you reload the firmware to the CPU? or is it more issues then just that...

If you cycle power it will work good (proper boot-up) one out of 20, the other 19 times all leds (all but the run) flash a few times then turn solid and stay solid for about minute then flash again, you can cycle power a few more times then it will boot up good and will run fine.

Anyone know of anything that can be done? I hate just tossing it out.

Thanks
Mark

Power Supply?

Hi Mickey,

I tried 2 power supplies and 2 racks, same with all...

I think you may be correct but something to do with the power supply on the CPU (unless thats what you are talking about)

Maybe the capacitor on the CPU?? but just guessing

EDIT: I also tried other swaping... changed the battery and reset the CPU

geniusintraining said:

all leds (all but the run) flash a few times then turn solid and stay solid for about minute then flash again

Click to expand...

The flashing is normal during boot.

The hardware manual is here:
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1747-um011_-en-p.pdf

The 5/04 troubleshooting starts on page 149. What are the last errors stored in the processor status after you reboot and everything starts up?

Publication 1747-UM011G-EN-P said:

If the status indicators
indicate:

• Power Status indicator is on
• FLT status indicator is on
• Status of all other status indicators do no matter

The following
error exists:

• A fatal error has ocurred

Probable Cause:

• Excessive noise or a faulty processor.

Recommended Action:

• Cycle power to obtain flashing FLT status indicator and default program
• Examine the error code following the power cycle. Take appropriate action
• Reload the program.
• Contact your local Rockwell Automation representative if the error persists.

Click to expand...

Check the Rack.....We had a Plc that would do something similar...we changed the power supply.... but still continues... problem was resolved by trial & error.... and we found that when we replaced the RACK... it worked fine...

porky said:

problem was resolved by trial & error...

Click to expand...

We use the term 'Poke & Hope' for this type of troubleshooting.

monkeyhead said:

The flashing is normal during boot.

Click to expand...

Thanks monkeyhead... but all leds flashing at the same time is not, normal boot up has the flt then the DH+ then etc... but on this one all LEDs (but the run) flash at the same time, then stay on.

If I get a chance I will get it to boot then see what the last error was/is

Thanks porky, but I tried that also...

GIT I had abad backplane that caused me alot of trouble. The processor would look like it was OK then when you went to communicate with it nothing. I see you have been there already. You should be able to flash this unit up to the FRN 10 If it has a white label. If you don't have the flash file call your local rep he maybe able to help you out. I had to spend 150 just to bring up my 5/05.

It is very possible that there is something wrong with the processor. If you have tried all of those steps and it still doesn't work, then that might be where your problem lies. I always thought that you would get a cpu fault if anything was wrong with the processor, but we had a processor go bad and not fault which caused lots of problems and damage. I suggest sending it to AB for testing.