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I have a "330v200" CCTV camera that died some while ago and now that I disassembled it, I discovered that the S4 diode blew up and another component is shorting out. However, I can't find a schematic for this board and am not sure which components these are.

CCTV camera board Above photo from the internet

Damaged CCTV camera board Above photo from my board

Any help is greatly appreciated.

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    \$\begingroup\$ Looks like an inductor. In that case, it should measure as "shorted" with a multimeter. \$\endgroup\$
    – Klas-Kenny
    Mar 29, 2022 at 13:29
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    \$\begingroup\$ The component you marked as shorted looks like a ferrite bead, so it would be expected to be a short when OK and open when faulty. \$\endgroup\$
    – Justme
    Mar 29, 2022 at 13:29
  • \$\begingroup\$ Thanks to both! I'll put that component back on the board. About the capacitor, it's measuring open line, should that be OK? If not, any suggested replacement? \$\endgroup\$
    – Fusseldieb
    Mar 29, 2022 at 13:32
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    \$\begingroup\$ Guessing wildly, the SOT 23-6 to the left could be switch regulator and the diode is either used as fast switching or as reverse protection. It can stand 40V reverse so it would have meant some unrealistically big voltage getting applied. More likely there was a short somewhere and then both the regulator and the diode tossed in the towel. \$\endgroup\$
    – Lundin
    Mar 29, 2022 at 13:42

1 Answer 1

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The left component could be a fuse, a ferrite or a chip inductor - in either of these cases it should short. The right one I think is a standard schottky diode like SD103AWS. That diode blowing up is not the cause of your board damage, just a symptom.

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  • \$\begingroup\$ Thank you for the answer! This definitively helped! I'll leave the inductor alone. However, the capacitor in the middle is measuring open and even on capacitance mode its measuring 0.00uF, with both components left and right removed. This doesn't seem ok, or is it? \$\endgroup\$
    – Fusseldieb
    Mar 29, 2022 at 13:42
  • \$\begingroup\$ For the short, I think it being a CCTV camera and it being exposed to long wires, a spike from a nearby strike or something might have been sufficient to kill it. \$\endgroup\$
    – Fusseldieb
    Mar 29, 2022 at 13:43
  • \$\begingroup\$ @Fusseldieb You need to remove it from the board before measuring capacitance. However, it could also be a very small one and then it depends on how good a tool you have to measure it. \$\endgroup\$
    – Lundin
    Mar 29, 2022 at 13:44
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    \$\begingroup\$ I didn't dig that far, but thanks for the tips. I replaced the S4 diode with a SS14 and turned the camera on, which made the capacitor in the middle go really hot. Then I replaced that capacitor with a random 22uF one that I found (was in a 12V board!) and tried again. After that replacement, it started working again. Thank you for your time! \$\endgroup\$
    – Fusseldieb
    Mar 29, 2022 at 16:24
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    \$\begingroup\$ That capacitor that became really hot after the diode replacement was probably the reason the diode blew (overcurrent). Or maybe not. But most importantly it works again :) \$\endgroup\$
    – Fusseldieb
    Mar 29, 2022 at 16:27

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