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Thread Tools | Display Modes |
04-15-2020, 02:06 AM
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Boardkiller
Join Date: Feb 2014
City & State: slovakia
My Country: slovakia
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 1,972
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Lenovo E520 - Low 3., and 5V ALW
Hello have this Lenovo E520 that have low 3.3 and 5V ALW voltages. i read 0.36V and 0.67V
cannot find datasheet of this ic BD95280MUV-GP, but everything looks good. no short, REG voltages OK, EN voltages OK, no heating. It looks like something tells this oc to make that low voltages. Have anybody some hint what can make this ic make low voltages on this rails? |
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04-15-2020, 02:08 AM
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#2 |
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Boardkiller
Join Date: Feb 2014
City & State: slovakia
My Country: slovakia
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 1,972
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Re: Lenovo E520 - Low 3., and 5V ALW
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04-15-2020, 02:18 AM
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#3 |
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Boardkiller
Join Date: Feb 2014
City & State: slovakia
My Country: slovakia
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 1,972
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Re: Lenovo E520 - Low 3., and 5V ALW
Pin 16 and 18 have no voltage
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04-15-2020, 04:59 AM
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#4 |
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Boardkiller
Join Date: Feb 2014
City & State: slovakia
My Country: slovakia
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 1,972
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Re: Lenovo E520 - Low 3., and 5V ALW
sry bad reading. have no REG1 and REG2
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04-15-2020, 05:10 AM
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#5 |
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Boardkiller
Join Date: Feb 2014
City & State: slovakia
My Country: slovakia
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 1,972
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Re: Lenovo E520 - Low 3., and 5V ALW
replaced ic and all works
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04-15-2020, 05:20 AM
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#6 |
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Moderator
Join Date: Jan 2018
City & State: York
My Country: UK
I'm a: Knowledge Seeker
Posts: 4,596
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Re: Lenovo E520 - Low 3., and 5V ALW
You must have had internal short or something.
Vo1 (27 pin) This is the output discharge pin, and output voltage feedback pin for frequency setting. When the voltage is beyond 4.4V from the external power supply during operation, it supplies REG1. |
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