Agreed, the CPU is not working... check the 3.6864MHz crystal under the CPU. If it is possible to locate the reset signal...
On Wed, May 9, 2012 at 12:23 AM, <b...@lysator.liu.se> wrote: > Hi Bob, > > The DB-9 looks fine even with magnifying glass. > The good one has a MAX232EWE IC, the faulty has a TC232EOE. I see > RS232-level coming in at pin 13 and going inside the Tbolt at pin 12 (ttl > level).So there should be no problem there. > > Have also swapped PSU board, so the problem is inside the actual GPSDO > board. > > The 232 level IC is a dual channel RX/TX translator. Anyone know what the > second 232 port is used for? > > -- > > Björn > > > 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) > > > > Bob > > > > On May 8, 2012, at 5:52 PM, b...@lysator.liu.se wrote: > > > >> Hi group! > >> > >> Just got a few Thunderbolts. It is a few PN 39448-61 and one PN > >> 38223-61. > >> Date codes from 9932 to 0025. This is the "normal" version with a 24VDC > >> power board and Tbolt board integrated in a small AL box with red > >> markings. One of the receivers is having a problem. Measuring from the > >> outside there is: > >> > >> 1) Takes the same amount of power as the working units.(to the > >> resolution measured) > >> 2) Has 10MHz output. > >> 3) Has 4.9VDC on antenna center pin. > >> 4) -8.9VDC stable on rs232 Tx pin (pin2 in DB9) > >> 5) 10MHz is 0.7Hz off after many power on hours with known good antenna > >> 6) TP9 & TP10 (close to the GPS board power connector) has 4.9VDC > >> 7) Tboltmon will not talk to the board. > >> 8) There is no serial output at all from the Tbolt. > >> > >> Differences compared to a good Tbolt > >> > >> 1) Tboltmon will ofcause communicate. > >> 2) After locking 10MHz will be very close to nominal > >> 3) TP9 and TP10 shows a square wave (ca 7V pp, 9.795625000kHz) > >> > >> I have looked at Tom's page at > >> > >> http://www.leapsecond.com/tbolt-faq.htm > >> > >> Brooke's at > >> > >> http://www.prc68.com/I/ThunderBolt.shtml#IC > >> > >> and John's at > >> > >> http://www.ke5fx.com/tbolt.htm > >> > >> Are there other good Thunderbolt sites? > >> > >> Has anyone done debugging of faulty Tbolts? Comments on what might be > >> wrong with my faulty unit? (I am not that experienced in hardware > >> debugging...) > >> > >> -- > >> > >> Björn > >> > >> > >> > >> > >> > >> > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
