[wajai1986]

My C4 Mux (Chinese clone) was working fine before, but suddenly stop getting power from car when connected with cable, when I try insert new battery in it, it can boot up.

I am sure the power from the vehicle is working, because i borrowed a C3 from a friend to diagnostic the vehicle after the C4 is not working.
And I have tried with another OBD2 cable between the car and MUX, but same result, the Mux would not boot up.
I thought the Mux was totally dead, but when I get home, I tried to put in some battery to the C4 Mux, then the Mux boot up without problem, but I have not try if the Mux could communicate with the vehicle through the obd2 cable.

Does any body know what's wrong with it & how to fix it?

[baner]

My C4 Mux (Chinese clone) was working fine before, but suddenly stop getting power from car when connected with cable, when I try insert new battery in it, it can boot up.

I am sure the power from the vehicle is working, because i borrowed a C3 from a friend to diagnostic the vehicle after the C4 is not working.
And I have tried with another OBD2 cable between the car and MUX, but same result, the Mux would not boot up.
I thought the Mux was totally dead, but when I get home, I tried to put in some battery to the C4 Mux, then the Mux boot up without problem, but I have not try if the Mux could communicate with the vehicle through the obd2 cable.

Does any body know what's wrong with it & how to fix it?

Seems that one of green fuses on front connector pcb is gone.

It can be repaired, no probs (if all other is OK with that SDC).

Regards!

[Albert J]

Does any body know what's wrong with it & how to fix it?
[/quote]



Seems that one of green fuses on front connector pcb is gone.

It can be repaired, no probs (if all other is OK with that SDC).

Regards!
[/quote]

Would it be possible to show a picture of a C4 board, and point out the fuse on it?
I have a C4 in a very similar condition, maybe it can be resurected.....

Thanks AJ.

[wajai1986]

My C4 Mux (Chinese clone) was working fine before, but suddenly stop getting power from car when connected with cable, when I try insert new battery in it, it can boot up.

I am sure the power from the vehicle is working, because i borrowed a C3 from a friend to diagnostic the vehicle after the C4 is not working.
And I have tried with another OBD2 cable between the car and MUX, but same result, the Mux would not boot up.
I thought the Mux was totally dead, but when I get home, I tried to put in some battery to the C4 Mux, then the Mux boot up without problem, but I have not try if the Mux could communicate with the vehicle through the obd2 cable.

Does any body know what's wrong with it & how to fix it?

Seems that one of green fuses on front connector pcb is gone.

It can be repaired, no probs (if all other is OK with that SDC).

Regards!

Thank you for your advise.

I checked those fuse resistance with Multimeter , they are faulty

[Albert J]

[/quote]


Seems that one of green fuses on front connector pcb is gone.

It can be repaired, no probs (if all other is OK with that SDC).

Regards!
[/quote]

Thank you for your advise.

I checked those fuse resistance with Multimeter , they are faulty
[/quote]

Great picture, thank You for that "baner"
Opened up one of my defective SDConnect units, and sure enough, was able to replace those fuses, within minutes. I used 1.5A self resetting fuses. Working great again. Thanks for the picture and solution. AJ

[Albert J]

Seems that one of green fuses on front connector pcb is gone.

It can be repaired, no probs (if all other is OK with that SDC).

Regards!
[/quote]

Thank you for your advise.

I checked those fuse resistance with Multimeter , they are faulty
[/quote]

Great picture, thank You for that "baner"
Opened up one of my defective SDConnect units, and sure enough, was able to replace those fuses, within minutes. I used 1.5A self resetting fuses. Working great again. Thanks for the picture and solution. AJ
[/quote]


Life was great for a while. Now another malfunction came up.
The MUX is indicating 0.0V from the car on it's own display, but clearly it's powered up from the car.
Obviously there is NO communication between the C4 mux and PC Software since it's indicating 0.0V Picture included.

Does anyone know what goes bad on this C4 Mux power supply boards, that is doesn't register the input voltage of 13.5V ???

Thanks for the help. AJ

[Marcos]

POST SELFTEST ???

[Albert J]

POST SELFTEST ???

Done a couple of SelfTests, neither one of them finished completely, so I could't take a screenshot. But it certainly done the SelfTest on the internal Battery power.
That was obvious. The 13.5V input Volts are not getting to the mainboard.
Measured both new fuses and they are both passing power, but one or the other little BS component is hanging me up. Frustrating all the inferior components.

[Marcos]

If your cable is fine (please test it), the next step would be to check harder the PCB where the round connector is installed. There are not so many components on it which can be easily checked without desoldering them . Also, look carefully at those linear connectors who are making the transfer from one PCB to the other. Some of them are poorly soldered.

[Albert J]

If your cable is fine (please test it), the next step would be to check harder the PCB where the round connector is installed. There are not so many components on it which can be easily checked without desoldering them . Also, look carefully at those linear connectors who are making the transfer from one PCB to the other. Some of them are poorly soldered.

Hi, thanks for the response, I have a couple of cables here, neither one of them have any use on them, and they both behave the same way.
One of the power supply boards passes no voltage at all from the vehicle,[0.0V], the other one shows 7.8V . I did not have any time today to inspect the boards for connection issues, and bad solder spots. Hope I get around to do that tomorrow, I'll post it.

I went through the board and improved on 2-3 solder-spots, and what I found was that as long as the board is cool it will report 13.5Volts from the car. But once it warms up it drops that voltage to 7.5V. That is telling me theat one or the other resistor is getting ready to go bad and this is how it behaves before it completely does.
Did not spot any solder issues on the main board which has the connection pins what looks like an IDE hard drive pin set.