On Tue, 29 Nov 2011 17:13:34 +0000 Bob Bishop <[email protected]> wrote:
> On 29 Nov 2011, at 16:38, Attila Kinali wrote: > > > On Mon, 21 Nov 2011 15:46:56 +0100 > > Attila Kinali <[email protected]> wrote: > > > >> As the usual approach to fix such transients would be to solder > >> a few capacitors at the right places, i'd like to first debug > >> which power rail is the one affected. Hence i'd like to ask > >> whether there are any schematics of the power supply and power > >> supervision circuitry available before i start reverse engineering > >> the board. > > 1. Make sure your power supply is up to the job, could be the voltage is > drooping when the transmitter powers up. It's a 25W supply, and yes, i checked that already. The voltage drop only affects the CPU as the other components in the box are happily working, even after the system crashed. > 2. Check all RF terminations in case of leaks. Pig tails going to antenna connectors? I doubt that they can leak much. And the i-dont-remember-the-names-of-those-ultra-small-coax-connectors are way too small to radiate enough power to affect electronics at that distance, especially with the pigtails connected. The WLAN board itself is well shielded. > 3. Apply ferrite rings to all non-RF cables, as close to the box as possible. The only non-RF cable in there is the 5V power going to a fan. Which is still inside the case. Just for reference, i'm an electrical engineer designing boards in the same ballpark as the net5501 for a living. I know what i'm doing and how to debug problems. My comment that it's most likely an issue with the on board power supply (ie the DC/DC converters) isn't just a baseless assumption. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
