tml 19 Posted October 10, 2013 Share Posted October 10, 2013 Hi, While attaching some wires to P3.3 and P3.4 I must have done some circuit short (but I barely believe it as I was watchful), the USB hub's green LED (LED102) turned off and now every time I attach the USB plug the TPS2041B (U403) gets hot (after approximately 3 seconds - then I have to unplug so not to burn that stuff). I can see the Bus 001 Device 009: ID 0451:2046 Texas Instruments, Inc. TUSB2046 Hub in the system once connected, that's all. Looking at the schematics at http://www.ti.com/lit/ug/slau533/slau533.pdf page 55 does not tell me much what might be broken, do you have any idea? Didn't check if the F5529 works at all yet. Best Regards, tml Quote Link to post Share on other sites
chibiace 46 Posted October 10, 2013 Share Posted October 10, 2013 got a multimeter? might be an idea to check all the resistors/diodes/caps. Quote Link to post Share on other sites
tml 19 Posted October 11, 2013 Author Share Posted October 11, 2013 got a multimeter? might be an idea to check all the resistors/diodes/caps. Hi, The circuit short is somewhere on the microcontroller part. Once I removed the 3v3 jumper forwarding voltage to MSP430F5529 the EZ-FET started to work, the TPS2041B (U403) stopped overheating. There is a full connection between 3V3 and GND on the microcontroller part. That means I just destroyed my LP and I only have it as EZ-FETLite :-( Right now I can see no easy way to identify which component causes the problem rather than demounting one after another. Regards, tml Quote Link to post Share on other sites
chibiace 46 Posted October 11, 2013 Share Posted October 11, 2013 multimeter would likely be able to find the short. what did you connect to the board, which pins, what would it have likely touched? Quote Link to post Share on other sites
cde 334 Posted October 11, 2013 Share Posted October 11, 2013 If you know its the 3.3v rail, that really narrows it down. C19-20, C29-31, R27, C17, R14-16, R31-32, C23-24, C14, and the f5529 itself Quote Link to post Share on other sites
tml 19 Posted October 15, 2013 Author Share Posted October 15, 2013 If you know its the 3.3v rail, that really narrows it down. C19-20, C29-31, R27, C17, R14-16, R31-32, C23-24, C14, and the f5529 itself Thanks! Unfortunately to be able to find the damaged one I have to start desoldering the components one by one. Quote Link to post Share on other sites
Fred 453 Posted October 15, 2013 Share Posted October 15, 2013 Either tracking down and fixing the problem interests you enough to go to that effort, or it doesn't. If it does, then you'll learn something about hardware defects. If not, then at least you've only written off part of a fairly cheap board. Quote Link to post Share on other sites
abecedarian 330 Posted October 15, 2013 Share Posted October 15, 2013 Either tracking down and fixing the problem interests you enough to go to that effort, or it doesn't. If it does, then you'll learn something about hardware defects. If not, then at least you've only written off part of a fairly cheap board. And when you find out which component failed, you might learn what caused its failure. Quote Link to post Share on other sites
tml 19 Posted October 16, 2013 Author Share Posted October 16, 2013 I desoldered the F5529 as first guess which eliminated the short circuit. I must have accidentally dropped the breadboard pin-wire onto MCU's pins which caused the MCU damage. Quote Link to post Share on other sites
ILAMtitan 86 Posted October 24, 2013 Share Posted October 24, 2013 Regrettably the MSP430's are not tolerant to voltages above VCCmax (about 3.6V). I accidently powered a prototype board with three MSP430F6779s (they are about $14 a piece) with 6V, and fried them all. A costly and time consuming mistake to fix. Quote Link to post Share on other sites
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