Teensy 3.5 no port
- Thread starter seemikedrum
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I bought a cheap toaster oven, reflowed the board and it works! Kinda warped the pcb and the pins didn’t want to go back in the bread board, but it’s doing fine.
Last week Tues-Fri I was testing the circuit in my backyard. It experienced a fair amount of thermal stress swinging between 30-60 degrees F and when I brought it back inside Friday evening before it got really cold, it stopped working after being inside for about 30 mins. I spent probably 12-15 hours over the next two days trying to get it working again through troubleshooting and asking questions here.
Most people would throw it away and buy a new one (I did buy another, it will be here Wednesday), but I had a strong suspicion it had a cold solder joint that cracked.
Sunday my neighbors put a toaster oven on Facebook marketplace and I bought it this evening as a last ditch effort to use it as a reflow oven to hopefully melt everything and re-connect whatever cracked. It Worked!!!!
Last week Tues-Fri I was testing the circuit in my backyard. It experienced a fair amount of thermal stress swinging between 30-60 degrees F and when I brought it back inside Friday evening before it got really cold, it stopped working after being inside for about 30 mins. I spent probably 12-15 hours over the next two days trying to get it working again through troubleshooting and asking questions here.
Most people would throw it away and buy a new one (I did buy another, it will be here Wednesday), but I had a strong suspicion it had a cold solder joint that cracked.
Sunday my neighbors put a toaster oven on Facebook marketplace and I bought it this evening as a last ditch effort to use it as a reflow oven to hopefully melt everything and re-connect whatever cracked. It Worked!!!!
jim lee
Well-known member
Yeah, but for how long?
In a past life.. I used to make engine controls for drag racing boats. Early on in the development process, I'd bolted a known working "Launch controller" into a test boat and if failed miserably. It worked on the bench, failed in the boat. Took it back to the bench and, of course, it worked again. Not that it was getting wet or anything. The entire product was a solid block of epoxy. In the end I found that the reason it was failing was that the mount didn't fit very well to the block and the forces of mounting it was putting odd stresses on the block -> transmitting these directly to the chip -> to the silicon. Screw on the base, part fails, unbolt it, part woks. Redesigned the mount to use rubber grommets and never saw that problem again. (Did toss out the cracked one though.)
Coud be a temperature thing?, Mounting thing?
-jim lee
In a past life.. I used to make engine controls for drag racing boats. Early on in the development process, I'd bolted a known working "Launch controller" into a test boat and if failed miserably. It worked on the bench, failed in the boat. Took it back to the bench and, of course, it worked again. Not that it was getting wet or anything. The entire product was a solid block of epoxy. In the end I found that the reason it was failing was that the mount didn't fit very well to the block and the forces of mounting it was putting odd stresses on the block -> transmitting these directly to the chip -> to the silicon. Screw on the base, part fails, unbolt it, part woks. Redesigned the mount to use rubber grommets and never saw that problem again. (Did toss out the cracked one though.)
Coud be a temperature thing?, Mounting thing?
-jim lee
- Status