First time 7i43 failure

Hi.
Yesterday I connected for the first time my new 7i43 to PC and it was a failure.
The 7i43 should work with a 7i47 and a 7i44.
First of all I configure all the jumpers:

W1-UP
W2-UP (5v tollerant seems a good idea)
W3-UP

W4-DOWN (EPP)
W5-DOWN (EPP)

W6-UP (USB powered)
W7-UP

Before power up the pc I connected the internal parallel port with a IDC flat cable to the 7i43. Never connected something on P3 and P4.
Started Linux and before start halrun I conneted the usb cable (new one) to a PC USB port and then the 7i43.
After that something blown up, red flash and smoke between USB connector and W6 jumper (component with P2R2 label, silkscreen says L3).
Immediatly I disconnected the usb cable.

I did some tests:
1) With PC poweroff, connecting IDC cable (EPP) and usb cable, the PC does not start
2) With Linux up and running, IDC cable disconnected (EPP) and USB connected to 7i43, the power led slightly blink (other two are off) and if I read voltage on P1 connector I get 2.1 V.
3) With PC poweroff, connecting IDC cable and 5v (from PC power supply) on P1 connector, USB disconnected, the PC does not start
2) With Linux up and running, IDC cable disconnected and 5v (from PC power supply) on P1 connector, USB disconnected, the three leds are bright.

It seems the combination IDC cable and power do some short circuit.
The IDC cable is a good quality cable and the orientation to pin 1 is OK.

I did also some tests configuring LinuxCNC using parport and the parport port seems working well, I can read some signal (example ESTOP) change on parport using AXIS.

Now I think the problem i the 7i43, I ordered a new one from a european reseller but I am afraid something can go wrong again.

Any idea? Advice?

Probably a disagreement on the function of pin 26 of the flat cable
The 7I43 connects this to +5V. Most MB headers have this pin open or
its a key (pin missing). If its grounded on the MB there will be trouble

You are right.
I have a GA-J1900N-D3V and the manual say pin 26 of lpt port is grounded.



Do you think I burned definitely the 7i43 or I can try to repair it?

I will cut the wire of pin 26 from the flat cable.

Probably just fried L3 (USB VCC noise filter)
Q1 might have been damaged but probably not

I confirm now it works using 25 pin flat cable (pin 26 excluded) and 5v in P1.

...
[ 296.981190] hm2/hm2_7i43.0: IO Pin 047 (P3-47): IOPort
[ 296.981292] hm2/hm2_7i43.0: registered
[ 296.981298] hm2_7i43.0: board at (ioaddr=0x0378, ioaddr_hi=0x0778, epp_wide ON) found


USB power is gone.
Where can I look for L3 characteristics and buy another?

Maybe I can not worry about USB power and not repair it? In this case I will use power on P1.

L3 is 2.2 uH 450 mA 1210 case

Do you have the vendor partnumber?

PCW wrote:

Probably a disagreement on the function of pin 26 of the flat cable
The 7I43 connects this to +5V. Most MB headers have this pin open or
its a key (pin missing). If its grounded on the MB there will be trouble

I ran in to the same problem. Motherboard died so replaced with a spare (GA-P35-DS3P) which only has internal parallel header. Made a 26 to 26 pin cable and could not get LinuxCNC to start. Saw this post and cut pin 26 cable and now works.