On 05/08/2012 11:58 PM, Bob Camp wrote: > Hi > > The first thing to check is the soldering job on the DB-9 connector. Second thing to check is the RS-232 level translator IC. (RS-232 in should create TTL etc) Does not explain why the OCXO remains stuck as if it was untrained. I suspect that the CPU never starts or hangs early. Cheers, Magnus