Sorry. Should have changed subject line before. Just changed it. The EEV blog link shows the transistors but it's too fuzzy to read SMT part markings. If I can get a code I'll try and look it up online. Thank you. Chris > On Aug 4, 2017, at 5:27 PM, Chris Waldrup <kd4pbj@gmail.com> wrote: > > Thanks guys. > I've opened up my T bolt and noticed a SOT23 packaged part has the top blown off. > The PPS BNC jack has U19 beside it. > The next part is blown. Could someone take a closeup of the five parts around U19? > The intact parts are marked: > 5Dz > 1AM > and two 2Az parts. > > > Chris > >> On Aug 4, 2017, at 4:13 PM, Arthur Dent <golgarfrincham@gmail.com> wrote: >> >> Actually that isn't my photo I linked to but one I just Googled. That is >> probably a board revision most people don't have but it was the first one >> I saw so I used it just to show that the GPS receiver is part of the >> only circuit board and not another easily replaceable board like in some >> other units. >> >> I just took a couple of photos of the later revision of the board for >> anyone interested in seeing what might be fried. In the photo of the >> top of the board the signal comes into a filter then to a 25db amp >> marked AM50002 by Macom. Above the filter near the input is where the >> decoupled +5VDC for the antenna is connected. If you are only reading >> 0.5VDC, if your're lucky it might only be the amp is fried and that >> could be an easy fix. If the 5VDC is ok with the amp input pin lifted, >> it might be the only problem. I wouldn't bet on it though. The 4031 I >> believe is a 1575.42 SAW filter >> >> The photo of the bottom of the receiver area shows a Sawtek filter and >> other parts. At the bottom of the photo is C460, a feedthrough capacitor >> and that might be where the receiver output is but where my Tbolts are >> working I don't feel the need to look into whether you could connect >> the output of a seperate GPS receiver there to make it work. >> >> I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz >> connections to SMA connectors on the back so I can test other oscillators >> or GPSDOs that don't have an easy way to monitor of graph the stability >> of those units and using Lady Heather gives me a good way to compare the >> graphs to ones I'm used to. You might possibly be able to replace the >> built-in receiver but it might be easier to buy a working Thunderbolt. >> >> >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20top%201_zpslgxunnyw.jpg >> >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20bottom%201_zpschvruppt.jpg >> _______________________________________________ >> 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.

Part is MMBT3904 > On Aug 4, 2017, at 5:39 PM, Chris Waldrup <kd4pbj@gmail.com> wrote: > > Sorry. Should have changed subject line before. Just changed it. > > The EEV blog link shows the transistors but it's too fuzzy to read SMT part markings. If I can get a code I'll try and look it up online. > > Thank you. > > Chris > >> On Aug 4, 2017, at 5:27 PM, Chris Waldrup <kd4pbj@gmail.com> wrote: >> >> Thanks guys. >> I've opened up my T bolt and noticed a SOT23 packaged part has the top blown off. >> The PPS BNC jack has U19 beside it. >> The next part is blown. Could someone take a closeup of the five parts around U19? >> The intact parts are marked: >> 5Dz >> 1AM >> and two 2Az parts. >> >> >> Chris >> >>> On Aug 4, 2017, at 4:13 PM, Arthur Dent <golgarfrincham@gmail.com> wrote: >>> >>> Actually that isn't my photo I linked to but one I just Googled. That is >>> probably a board revision most people don't have but it was the first one >>> I saw so I used it just to show that the GPS receiver is part of the >>> only circuit board and not another easily replaceable board like in some >>> other units. >>> >>> I just took a couple of photos of the later revision of the board for >>> anyone interested in seeing what might be fried. In the photo of the >>> top of the board the signal comes into a filter then to a 25db amp >>> marked AM50002 by Macom. Above the filter near the input is where the >>> decoupled +5VDC for the antenna is connected. If you are only reading >>> 0.5VDC, if your're lucky it might only be the amp is fried and that >>> could be an easy fix. If the 5VDC is ok with the amp input pin lifted, >>> it might be the only problem. I wouldn't bet on it though. The 4031 I >>> believe is a 1575.42 SAW filter >>> >>> The photo of the bottom of the receiver area shows a Sawtek filter and >>> other parts. At the bottom of the photo is C460, a feedthrough capacitor >>> and that might be where the receiver output is but where my Tbolts are >>> working I don't feel the need to look into whether you could connect >>> the output of a seperate GPS receiver there to make it work. >>> >>> I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz >>> connections to SMA connectors on the back so I can test other oscillators >>> or GPSDOs that don't have an easy way to monitor of graph the stability >>> of those units and using Lady Heather gives me a good way to compare the >>> graphs to ones I'm used to. You might possibly be able to replace the >>> built-in receiver but it might be easier to buy a working Thunderbolt. >>> >>> >>> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20top%201_zpslgxunnyw.jpg >>> >>> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20bottom%201_zpschvruppt.jpg >>> _______________________________________________ >>> 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.