Happy Weekend ! Here is obd2shop.co.uk customer share with us :
How to do if your multiplexer is dead, not powering up via any adapter cable when using MB SD connect c4 testing
Please Kindly Notice:
TRY AT YOUR OEWN RISK!
First open the MB SD C4 main unit. Slide PCB out a little bit, from the connector side, so you can see the units buttons wiring. Carefully pry the lock out & up, after that you can pull the wiring and PCB out.
Then Open 4 Main PCB screws, Carefully wiggle the PCB off from another, it might be pretty tight, so carefully, side from side!
Disconnect the LAN cable, carefully, pretty easy to break the small clip.
Then you can disconnect the Connector PCB, very carefully, might be really thight! Again slowly from both sides. You now have access to the small Fuses.
You can use multi-meter to see if they work, usually the LAN connector side 5A is burnt. So desolder the broken one, install new & enjoy your powering up mux again!
This repairing above requires experienced and professional techniques; or you are suggested to buy a cheap clone MB SD Connect C4 of high quality to replace it. Google to get the good one. I helped to put the first site here for you (no affiliation to the vendor)
Hope it would help you!
Check more information about MB SD C4 please click:
http://www.obd2shop.co.uk/wholesale/mb-sd-connect-compact-4-star-diagnosis-newest-arrival.html
Engineers highly recommend you the combination tool
MB SD C4 Plus DELL D630 laptop ready to use