[time-nuts] Lpfrs-10 serial port failure

[HB9DRI, Alex Artieda]

Dear friendsIm totally new in this list, looking for a solution to a problem with my Lpfrs-01.I had this unit second hand, in optical an funtional pristine condition , take only 3min to lock. All looks good except I cannot connect to the serial port, the device specified TTL Rx and TX in the lable, no response at all when send M, when is connected to a USB uaart converter and I send M the TX line show a permanent 3.6vdc and a train of pulses show up in the oscilloscope, at the same time the DXine is clamp to 1.4vdc and nothinig appears, suspect the serial interface buffer is damage.I will apprecite some advice to repair the unit, I try tl fk d a diagram with no success, only few tier down photos, maybe some body can point me where I xan sfart looking, maybe a IC to replace.Any help is welcome.73 de Alex, HB9DRISent from my Galaxy