Patrick Great job on the pix. Very helpful. Interesting in many ways the 4040 appears newer in design then the 4050. What is different is that in the 4050 the Cs tube multipkliers and such are in a magnetic shield. But the RF sections appear very similar. Noted the ugly cap and you may have more evil ones to deal with. Or damage to the board. In the 4050s the supply was a big 28V linear lambda. Here I see its a switcher. Again seems newer in design. Note on the eevblog that the 28V supply generates a 32V supply. Thats critical to operation. In the 4050 its a small multi transistor converter. DC/DC boost on top of the 28V supply. That may be hiding under the bottom cover on the module with some 8 screws. The caps inside made a mess of the inverter as they leaked their contents on the board and it dissolved all traces of the traces. Even under a microscope and various lighting it was difficult to reconstruct the design. Unfortunately on that same board were two other control systems and they were damaged. However cleaning all the damage out and rebuilding the traces did allow the control circuits to work. The converter was not recoverable. Solution install, a 32V supply. Especially since I have no intent to run it on batteries. When I had most of it figured out, like you I simply used external supplies and that showed the unit was operable. Will be good to see what more you find. Regards Paul WB8TSL
On Mon, Sep 28, 2020 at 4:25 PM Patrick Tanner <[email protected]> wrote: > Have made some progress. > Looks like bad caps. Capacitor "CA" is especially naughty. > > https://photos.app.goo.gl/Ye91Fv4Nmuj4xb7n8 > > Pics and measured supply data: > https://photos.app.goo.gl/dNWKyysC1QykCLWc8 > > > https://drive.google.com/file/d/1t1xjyNTbdwY_j7pg5rt_94GTY68R3ZbS/view?usp=drivesdk > > Thanks to Ed Palmer for the excellent thread over at eevblog detailing > this. > > Patrick > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
