Is it possible to somehow verify that the U551 chip is the one causing problems?

Many many thanks, mate. It helps me a lot. Finally able to fix the issue. now it is working fine. Again thanks. 73 S21APJ

Many schematics can be found on Hugen's github repo - some as *.png or *.jpg, but you should be able to convert them to *.pdf yourself: https://github.com/hugen79/NanoVNA-H/tree/master/doc HTH Martin

Thanks, I did some more checks: power supplies on the pins of the various devices were ok, clocks were also present (except the 32 kHz, I guess it's used maybe only for the RTC during power down?) but

So I have SAA-2n that was working have maybe turned it on a few times at most... Went to test my new ant and cable today and the screen would touch to have menu come on but that was it... the test was

Without screen it works, with screen cleaned and reassembled, it doesn't work

Thank you very much for your generous offer, but im thousand miles away from state.

YES

Thanks, I am encouraged to give it a try. I already have the hot air gun and am getting fairly good with it. One day when I am feeling brave I may give it a shot. I don't have anything to lose, as I c

I am not a fan of the Si5351. It was intended to be used for digital clock generation for processors and peripherals, not for RF signal generation where reasonable signal quality is needed. Its only a

Folks, A few of you have been looking for various test equipment manuals. Please refer to this site: http://www.ko4bb.com/getsimple/index.php Enjoy and have a Happy New Year!! ... Larry

Could you show a picture with your final arrangement?