Hi, I checked the output across OSC2 and GND, it was 1.6V. Sairam ________________________________ From: Ray To: Microcontroller discussion list - Public. Sent: Mon, March 8, 2010 9:25:15 AM Subject: Re: PIC 16F877A Microcontroller problem Also you can use a DVM on OSC2/CLKO and see if it is some average dc voltage. 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: > Dear All, > I developed a basic board to help people learn PIC microcontroller > programming. The board is based on the PIC 16F877A microcontroller > and I have enclosed a picture of the board at the following page: > http://mechatronicscraze.wordpress.com/2010/02/08/the-board-has- > been-populated-and-it-is-ready/ > The board was tested and the results were successful. I ordered for > another set of 10 boards and populated four of them. I faced a > weird problem with three boards. I identified that in one of the > boards, the board didn't work because of a low quality tact switch > that kept my MCLR pin low. I avoided soldering the tact switches in > the other two boards. In both these boards, I see that the MCLR pin > is high and the voltage is 5V between pin 11 and 12 of 16F877A. > However, both the boards were not functional. On replacement of the > crystals and capacitors, one of the board has started functioning. > The other board is not functional even after replacing three sets > of capacitors and crystals of both XT and HS frequencies. I have > taken care that I have set the correct fuse bit before I build my > program. (XT or HS at address 2007 and low voltage programming was > disabled) > The problem is that I don't have an access to oscilloscope and I am > not able to identify the problem behind the board. I am very sure > that someone might have faced this problem. I would be glad if > anyone could offer me assistance for the same. > > Sairam -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist