[time-nuts] Brandywine GPS-4
j.bastemeijer at tudelft.nl
Wed May 13 06:57:00 UTC 2009
The serial connection is not the problem (unfortunately). It seems a
thermal problem.... When I switch on the unit it takes a couple of
minutes before the Error-LED starts flashing. Doing a "fast" power-cycle
immediately gives an error-warning (the red-LED start flashing almost
immediately after switch-on). When I let the unit cool down for some
time (say ten minutes) it takes a couple of minutes before the error-LED
What I will try next is use some cool-spray on the DC-DC converters and
see if that gives any change in the behaviour.
To my opninion everything inside gets quite warm... Maybe it is a bad
capacitor (high ESR).
Is there any other good source for technical information on these units
(schematics, service docs etc.)? Except for the manual wihich is on
73 Jeroen PE1RGE
Hal Murray wrote:
>> The unit used to work.... so dip-switch, cable etc. are OK. The thing
>> I suspect is indeed, some problem with the FLASH and/or EPROM.
>> However, I have no useful source of information about that.
> Did it work with the serial port connected to a PC like you are using now?
> Or did you just see the green LED go on?
> What happens if you try it without the serial connection? (There are some
> control signals on that connector that may not match normal RS-232 usage.)
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 355 bytes
Desc: not available
More information about the time-nuts