--===============1547053856== Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by pch.mit.edu id o283tRFQ002051 Also you can use a DVM on OSC2/CLKO and see if it is some average dc volt= age. if about 50% VCC then oscillator is working. Depending on loading of meter it might be less. But some dc voltage. Ray On Sun, 7 Mar 2010 19:30:35 -0800 (PST), yamanoor sairam wrote: >=A0Dear All, >=A0I developed a basic board to help people learn PIC microcontroller >=A0programming. The board is based on the PIC 16F877A microcontroller >=A0and I have enclosed a picture of the board at the following page: >=A0http://mechatronicscraze.wordpress.com/2010/02/08/the-board-has- >=A0been-populated-and-it-is-ready/ >=A0The board was tested and the results were successful. I ordered for >=A0another set of 10 boards and populated four of them. I faced a >=A0weird problem with three boards. I identified that in one of the >=A0boards, the board didn't work because of a low quality tact switch >=A0that kept my MCLR pin low. I avoided soldering the tact switches in >=A0the other two boards. In both these boards, I see that the MCLR pin >=A0is high and the voltage is 5V between pin 11 and 12 of 16F877A. >=A0However, both the boards were not functional. On replacement of the >=A0crystals and capacitors, one of the board has started functioning. >=A0The other board is not functional even after replacing three sets >=A0of capacitors and crystals of both XT and HS frequencies. I have >=A0taken care that I have set the correct fuse bit before I build my >=A0program. (XT or HS at address 2007 and low voltage programming was >=A0disabled) >=A0The problem is that I don't have an access to oscilloscope and I am >=A0not able to identify the problem behind the board. I am very sure >=A0that someone might have faced this problem. I would be glad if >=A0anyone could offer me assistance for the same. > >=A0Sairam --===============1547053856== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: 7bit -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --===============1547053856==--