JONATHAN MORE

Quickstart Board Issue - gets too hot - how to fix

Discussion created by JONATHAN MORE on Apr 13, 2011
Latest reply on May 2, 2011 by Clay Cowgill

The first cut (Assembled / BOM per Rev C schematics) Quickstart boards get hotter than expected. The reason is a BOM error where a 10 ohm resistor was used instead of what I imagine was supposed to be 10K ohms. See attached images for the location of R199.

 

To determine if your board has this issue, measure R199. If it is 10 ohms, replace it with something in the 10K - 50K range. However, notice that it is a 0201 part, so find someone with a Metcal, good eyes, and steady hands.

 

Schematics affected: SPF-26565_C.pdf (shows R199 as 10 ohms). Assy numbers affected not known.

 

Freescale has been informed of this issue.

 

Attached also is image (R199_fix2.jpg) of a way to fix without specialized tools. Remove R199 by scraping it off with a soldering iron. Then attach a 10K 0603 or even an 0805 resistor from the polyfuse to the FET as shown. The value shown in the picture is 3322 or 33.2K - anything from 10K to 50K should be fine.

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