Mod Details
PremiumNo Difficulty
Mod ID1866
Creditevilution
For
Linkhttps://www.evilution.co.uk/mod/sam-unit-solder-repair.htm Copy to ClipboardLead-free solder is shit. Fact!
It was shit out onto our laps by the EU overlords because “lead bad”. What I think the real reason was that it limits the lifetime of electrical items so people have to buy more stuff when your old stuff fails.
Lead-free solder is horrible to work with. It requires more heat and doesn’t flow as well. It’s also more rigid which causes cracking and “whiskers”. Lead-free solder was so bad that medical, space and army electrical products don’t have to use lead-free solder. They can stick with the far superior 60:40 lead based solder. Have a look at the lead-free solder issues here.
SAM Unit Failures
All of the electrics will suffer but the biggest issue is the SAM unit. There are a lot of large solder joints on the PCBs. A cracked solder joint will affect voltage or data transmission and that will stop the car functioning correctly.
The other issue is that a replacement SAM is expensive and requires coding which is even more money.
Warning
If you have the balls to disconnect the SAM, open it up and resolder the solder joints, do it all in 1 go. Don’t do some now and some in a year when more solder joints fail. The reason is that the copper tracks work harden as you unfold the PCB. The more you fold/unfold it, the more chance you have of cracking a copper PCB track.
Before you get in there, make sure you have everything you need.
A soldering iron,
60:40 lead based solder,
Desoldering gun,
Or desoldering wick and flux.
Some people just reheat the lead free solder to fix the cracked joints. Don’t do this.
Desoldering
Do 1 connector at a time. Remove as much of the old lead-free solder as you can before resoldering the joints with lead based solder.