6i25+7i77 CR16 staying red

Hi there,
First of all, happy new year !

I need some help on this issue, I can't figure what i'm doing wrong.
I've bought some years ago (2-3 ?) a 6i25+7i77 plug and go kit form mesa but never used it.
Now the time as I've build the mecanical side.

Issue is:
This damn CR16 is showing red.

What I've checked so far:
Made my own cable to use P2 internal connector, tested it with multimeter, is ok.
TB1: 5V is ok, computer psu is providing it to TB1. W5 has changed.
TB2: 24Vdc is ok, provided by an other psu. W1 is in default position Vin is th same as VField, checked at 24V.
Differential encoders is working.

Short story:
Was running Lcnc 2.7 on wheezy, discovering it has ended LTS, decided to upgrade to buster, so I've upgraded to Lcnc 2.9.0pre and had to build it (was my first time maybe I've done something wrong)
Running 7i77x2r.bit (not sur if needed for using P2 on 6i25 ?)
Did try 7i77x2.bit with no change.

Interesting facts (or maybe useless):
With no 7i77 connected to the 6i25, PnCconf is still showing TB7 TB8 with "internal data form 5i25", and in fact everything.
Starting PncConf is throwing an error with hostmot2 firmware not present on hard disk.
CR1-3-6-7 are yellow CR15 off, and of course CR16 red.
Starting Lcnc doesn't change CR15-16.
If i'm starting Lcnc with wrong bitfile/conf file, it show error as expected as it can't find related pins.

I can't find my db25 cable to see if it will change something.

Could it be my build of linuxcnc ?

Any help will be appreciated as I'm struggling with this one.

Are W4 and W12 in the left hand position?

Did you reload the firmware after updating to 7i77x2r?

(yes, the 7i77x2r firmware is needed if running a 7I77 on a
flat cable connected to P2 at least if you dont want to renumber
all the sserial and encoder channels)

The red LED could also indicate a real time issue, does LinuxCNC run at all?
Are any .7I77. pins present?

W4 and W12 are default, I've juste checked it's in left hand position.
Yes did reload and even power cycle just to be sure.
Not sure about this, LinuxCNC is starting, I can see starting logo and then the frist page of axis. No error message. But I'm not sure if realtime is starting or not.

Maybe not, I've started LinuxCNC form terminal and I've got this :

That looks like the analog section was found but the field I/O was not
This could be a 6I25 , cable or 7I77 issue.

You might check that the drive configuration string is OK and that your flat cable is
OK as well. If those things are OK the best thing is to request a RMA and have the
complete card set evaluated.

Damn !
I run halrun and I got the same things: only 7i77 analog part.
I've already checked my flat cable, it should be ok.
I will find DB25 cable and try with it, it should be somewhere...
It has worked when I got the cards, I remember to see CR15 blinking in green.
At least it should tell if it's 6i25 or 7i77.

What do you mean by "drive configuration string" ?

I meant driver configuration string

Last news:
I've found this DB25 cable, so I've tried it: reloaded 7i77x2 firmware, plugged everything and .. same story.
Refuting a dead 7i77, I had a spare HDD; installed wheezy with linuxcnc 2.7 with no luck.
I even tried to power the 7i77 by the 6i25, it didn't change anything.
I guess it's really dead.

Beside a RMA form Mesa can something can be done ? I expect shipping cost from France to USA is quite high... maybe buying a new one will be cheaper.

Can somebody explain to me what is this driver configuration string thing ?

And more important: what can be the cause to a dead I/O field ?
I don't want this to happen again and want to find why.

Things I could have done wrong, but I have no memory of this:
-Reverse polarity on I/O field (very unlikely, should I see some smoke if this happen ?)
-Wrong custom flat cable, most likely reversing connector or cutting the wrong side since it's 25 to 24.
-Messing with jumpers to power 7i77; W1 on 6i25 and W2 on 7i77.
-I'm powering I/O field directly with a +24Vdc power supply with no relay like described in the manuel. Slew rate to high ? I guess I could check it with a scope just to be sure.

Anyway thanks for helping me.

Did you try both 6I25 connectors in case there's a bad I/O bit?
If the 7I77 is bad, we can ship you a replacement.

We have occasionally seen ( in maybe 2 or 3 out of 1000s of cards)
DSPICs that forget their programming and that may be whats
happened here.

Yes I've tried both P2 and P3 connectors.
P2 connector with provided cable, tested with 7i77x2 firmware.
P3 with a custom made, tested with 7i77x2r firmware. (tested only on debian 10, but I don't think it's matter anymore)

I have a JTAG-usb and PICkit3-usb if it can help.

You could try reprogramming the DSPIC that would at least determine if the DSPIC forgot its programming or there is another issue. If you cannot get it running, send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. and we will assign an RMA# and send you a replacement card

7I77 Digital side DSPIC firmware:

freeby.mesanet.com/7I77DS14H1.HEX