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Softorck Ensemble II: 1.8vdc and 150mA at the output of the 7805
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Hi everybody,
after ten years my softorck ensemble has encountered and hardware failure. It tunes regularly but hears nothing and at the output of the 7805 regulator I see just 1.8vdc and a much more current drain than usual (around 150mA). U7 becomes hot! I replaced R14 and U7 but it has still the same issue. Removing also the ATtiny makes no change. Do you have any idea on what it could be? 73, Franco iz2oos |
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I guess U8 FST3253 at the antenna input has become defective. Impedance across C37 is only 2ohms. C37 was fine. Removing U8 there very low current drain as it should be and at the output of the 7805 I see now 5vdc as should be.
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Il sabato 29 agosto 2020, 14:00:41 CEST, Iz Oos via groups.io <iz2oos@...> ha scritto:
Hi everybody, after ten years my softorck ensemble has encountered and hardware failure. It tunes regularly but hears nothing and at the output of the 7805 regulator I see just 1.8vdc and a much more current drain than usual (around 150mA). U7 becomes hot! I replaced R14 and U7 but it has still the same issue. Removing also the ATtiny makes no change. Do you have any idea on what it could be? 73, Franco iz2oos |
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Repaired! It was U8 FST3253, the two pins that are connected to the isolating transformer at the antenna input! The nice thing of the Softrock is that it can be relatively easy to detect an issue and repair at component level myself with a few bucks. I agree that Softrocks cannot be compared to the big three radios as somebody say, luckily!
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73 Franco iz2oos Il domenica 30 agosto 2020, 00:33:06 CEST, Iz Oos <iz2oos@...> ha scritto:
I guess U8 FST3253 at the antenna input has become defective. Impedance across C37 is only 2ohms. C37 was fine. Removing U8 there very low current drain as it should be and at the output of the 7805 I see now 5vdc as should be. Il sabato 29 agosto 2020, 14:00:41 CEST, Iz Oos via groups.io <iz2oos@...> ha scritto: Hi everybody, after ten years my softorck ensemble has encountered and hardware failure. It tunes regularly but hears nothing and at the output of the 7805 regulator I see just 1.8vdc and a much more current drain than usual (around 150mA). U7 becomes hot! I replaced R14 and U7 but it has still the same issue. Removing also the ATtiny makes no change. Do you have any idea on what it could be? 73, Franco iz2oos |
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