Slc 5/05

I've got a 5/05 (1747-L551 Series C) that has a solid fault light and no communications. I have done a lot of digging here and on Rockwell's KB, seems like the likely culprit is corrupt firmware. I found a post from Ken Roach that indicated the firmware is able to be upgraded, he even was kind enough to post the part number for the upgrade kit. My question is, how do I upgrade firmware on a processor I can't communicate with? Hopefully I am missing something painfully obvious. Thanks guys

first thing I would do is to power down the plc, remove the battery, and short the capacitor for 30 seconds in order to set the unit back to factory defaults.

then power the unit on.
you may be able to communicate with the plc and force ownership so you can download the program.

I did that on a slc 5/03 several years ago and it's still running.

james

I’m assuming that you have tried both the Ethernet and DF1 (serial) port? If not try getting in via the DF1 port. It defaults to 19.2kbaud, 8,n,1. If you can’t get in through it then default the processor and see if again you can get into it. If you can’t communicate with it after defaulting you might have a hard fault that you can’t recover from (you can’t upgrade the firmware (that I know of) without the communications ports).

I agree with the others default it first.

https://www.google.com/url?sa=t&rct...Ig8UD8wE25lV_b8aQ&sig2=6yCiqQxXrEIBQdczba-ICA

Sorry guys, I should have put that piece of info in my original post. I did short VBB to GND to reset to factory. No good on DF1 using either auto configure or entering settings manually. No response on Ethernet by any means either. I figured that no communications meant no way to fix the firmware, but there a lot of tricks some of you guys know. I did find a tech bulletin on KB (#60708) that indicated this could be caused by faulty SRAM in certain series of processors made in certain time frames.

Just a quick mention, I have found that shorting the VB and ground works every time, but.... sometimes it takes longer than 30 seconds. I would do it for more like a minute or two just to ensure that it is indeed defaulted.
Its hard to conceive that after this procedure the unit is not visible through the DF1 driver and a serial connection, unless its totally toasted! I have never seen this personally that I could not establish the serial DF1 connection after defaulting.
One other thing, how is your serial connection set up?? serial to USB or with a dedicated serial port? Sometimes if you are using serial to USB there a few tricks to make that work in itself.

One thing to look at when the SLC is powered up, is the RS232 port light blinking? Also did you have a problem with the power supply when this happened that it blew the fuse. If the RS232 port light is not blinking try another power supply.

Thanks for the ideas guys. I learned the hard way once before that if Rockwell says to do something for "x" time, better triple it just to be safe. Held the pins shorted for over 5 minutes several times. I dusted off my old D630 this morning, it has an old school serial port. Still no luck. Threw it in another rack, no blinking on the 232 indicator, still no comm of any kind. Looks like I have a genuine brick on my hands, but again, thanks to all for the brainstorming.