Polarity reversed to Ktag... can you fix it?

[Makx]

Hello all, good morning.

Completely pissed, I attached the red to black and black to red... what do you want me to say more.... then I turned on the power supply :/

the tool now works for the readings at the desk that I tried but does not power the ecu. I can do the reading just powering the ecu from the power supply.

Wonder if anyone can help me locate the components that you are burnt.

It seems to me that before combine is ******* the red led of the instrument will power up with only the 12V power supply, without connecting to usb, but I'm not sure of this recollection.

In the little experience I have, I believe I have identified a resistance leg R 178 10K.
I left it mounted and jumpered with a equivalent but still I do not see the red led turn on.

What's worse is the strong probability that it was also the R 180, that sort of viewfinder, one with the screen-printed since I don't find continuity with any scale of impedance between the center and the outer ring; in this I have continuity with no impedance between the inner rings.

can you tell me how should I check this or give me some way to "bypassarla".

Any tip is more than welcome.
Thanks

[ugoboss]

I can't help you for the resistors, but I can confirm that the red led turns on when foods the ktag with the 12v and not when the attacks to the usb port of the pc.

[alex210392]

Hello all, good morning.

Completely pissed, I attached the red to black and black to red... what do you want me to say more.... then I turned on the power supply :/

the tool now works for the readings at the desk that I tried but does not power the ecu. I can do the reading just powering the ecu from the power supply.

Wonder if anyone can help me locate the components that you are burnt.

It seems to me that before combine is ******* the red led of the instrument will power up with only the 12V power supply, without connecting to usb, but I'm not sure of this recollection.

In the little experience I have, I believe I have identified a resistance leg R 178 10K.
I left it mounted and jumpered with a equivalent but still I do not see the red led turn on.

What's worse is the strong probability that it was also the R 180, that sort of viewfinder, one with the screen-printed since I don't find continuity with any scale of impedance between the center and the outer ring; in this I have continuity with no impedance between the inner rings.

can you tell me how should I check this or give me some way to "bypassarla".

Any tip is more than welcome.
Thanks

I see diodes in the vicinity of the entrance (from the image so it seems to me, to see) also check those, bring them as a protection reverse polarity (see hard drive computer) just replace them and everything returns to work

[Makx]

Thank you for the precious tips. also the certainty that the red led should light up is very helpful.
The diodes I checked are mounted on the card, and I have the impression that (unfortunately) are not skipped.. this is a marked B4 (equivalent ss0540) and read ET GP 518 (but I'm not finding any matches for this code).. I will make other tests on these to see if I turn on the led but I'm still looking for a datasheet and not do other damage bypassandoli before taking them off.
meanwhile, thanks, and I update if I have news

[alex210392]

Thank you for the precious tips. also the certainty that the red led should light up is very helpful.
The diodes I checked are mounted on the card, and I have the impression that (unfortunately) are not skipped.. this is a marked B4 (equivalent ss0540) and read ET GP 518 (but I'm not finding any matches for this code).. I will make other tests on these to see if I turn on the led but I'm still looking for a datasheet and not do other damage bypassandoli before taking them off.
meanwhile, thanks, and I update if I have news

Check that there is voltage on the diodes, could also be Zener diodes, you can try to dissaldarli in order to understand if they are there for protection of reverse polarity or to straighten the input voltage, if you have them for the first cause must operate dissaldandoli if the second cause does not change anything