开云体育

PS-7 Troubleshooting Tips

bill KE7KK All Messages By This Member #82044 开云体育 Hi Drakey's I purchased an estate sale PS-7 that has no 13.8 v output. Both fuses are good, 120v on both fan plugs, no obvious burt components, transformer "thud" felt? when powered on by the TR-7 . Any hints on were to start or common failures ? Tnx Bill KE7KK??
Gary Follett All Messages By This Member #82046 开云体育 I don’t think I have ever seen. PS-7 with zero output… First check the voltages across the two big electrolytic cans. This voltage should be about 18 volts or so. The most likely candidate for failure in this supply is the 723 regulator. These have not been made for many years but are plentiful on eBay. Gary W0DVN toggle quoted message Show quoted text On Jan 18, 2025, at 2:52?PM, bill KE7KK via groups.io <Wkipping@...> wrote: Hi Drakey's I purchased an estate sale PS-7 that has no 13.8 v output. Both fuses are good, 120v on both fan plugs, no obvious burt components, transformer "thud" felt? when powered on by the TR-7 . Any hints on were to start or common failures ? Tnx Bill KE7KK??
Evan All Messages By This Member #82049 Possibly dirty pots (I know it sounds strange but caused my PS-7 to fault) or something in the sensing circuitry for the crowbar. On Saturday, January 18, 2025 at 03:52:43 PM EST, bill KE7KK via groups.io <wkipping@...> wrote: Hi Drakey's I purchased an estate sale PS-7 that has no 13.8 v output. Both fuses are good, 120v on both fan plugs, no obvious burt components, transformer "thud" felt? when powered on by the TR-7 . Any hints on were to start or common failures ? Tnx Bill KE7KK??
George Rybicki All Messages By This Member #82058 Mine had a bad zener diode.
bill KE7KK All Messages By This Member #82066 开云体育 Well by bad on this one, was powering the PS-7 on a Varic, works fine direct to 120v mains ! Dah Bill KE7KK

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