Bismar
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- Nov 9, 2008
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Originally Posted by Bismar /img/forum/go_quote.gif I reflowed U2U and U3U still ~4.5 volts on the 3.3v test point. Is it possible i may have damaged one of the SMD's? And if so, how do i test if they are dead? |
Originally Posted by amb /img/forum/go_quote.gif Nothing will cause the voltage regulator to output more voltage than what it's supposed to output, unless its ground reference pin is not making contact to circuit ground, or there is a short circuit from its input to output (which could be an internal short due to a blown regulator, or a solder bridge somewhere, or a PCB defect). You said that you/ve reflowed the regulator's joints, so you've probably eliminated the first possibility. That leaves the others. Have you measured the resistance between pins 1 and 5 of the voltage regulator chip? |
Originally Posted by amb /img/forum/go_quote.gif I would try removing U3U and see if the short persists on the board, or if it's within the chip. |