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LED Pins are shorted to ground

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bbrotherone

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CHARGED.PNGCHARGING.PNG

Hello.

As you can see the attached files, two pins on LEDs are shorted to ground. It is PCB Soldering problem happened. It seems to destroy or fool the circuit.
While charging, Only Red LED lights on(this is expected result) and I did not want any current flow across R1 into ground(Blue line). Voltage drop across the LED is shown to 5V because it is shorted to GND.

When charged, Only greed LED is supposed to be on, not Red LED.
Even charged over 10 hours, only RED LED stays on. Green LED is never turned on(this is the problem to solve....).
Could you analyze this problem and share your idea?

V1 : Power from the USB
V2 : Voltage at STAT pin from charge controller based on the states.
 

What are you talking about? Charging? What charging? All I see is two voltage sources.

Your red LED has no current limiting resistor. It is connected from a 5 volt supply to ground. Assuming it doesn’t get destroyed from overcurrent, why would you ever expect it to turn off?

As far as why your green LED doesn’t come on, either it’s damaged or wired incorrectly.
 

What are you talking about? Charging? What charging? All I see is two voltage sources.

Your red LED has no current limiting resistor. It is connected from a 5 volt supply to ground. Assuming it doesnÂ’t get destroyed from overcurrent, why would you ever expect it to turn off?

As far as why your green LED doesnÂ’t come on, either itÂ’s damaged or wired incorrectly.


Sorry, I shouldve explained in detail.
V1 is the power from USB charger.
Mcp73831 charging control IC controls the STAT pins depends on the charging process.
V2 voltage source is the STAT pin at MCP73831.
While charing, Vstat is 0.6v and when charged, Vstat becomes 4.7v.
 

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  • 2708629D-7F3C-4B7D-9DAA-8853CB2890D3.jpg
    2708629D-7F3C-4B7D-9DAA-8853CB2890D3.jpg
    155.6 KB · Views: 149

What a mess!!

First of all, you’re going to draw over 50mA from V2 when it’s high, exceeding its limit. And, again, why would you expect an LED that’s connected directly across 5V to to turn off? Have you measured voltages in your actual circuit?

What is the point of R1 other than wasting 43 mA?
 

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