EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: Jane on May 05, 2018, 08:17:52 pm
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I bought a Flir thermal camera and still learn how to use it.
I would like to use it for reparing electronic devices. Recently I tried to repair a mobile( old Nokia 6303) that had a short circuit( when connected to a power supply it drew some current).
So I used a camera and found out CPU had the highest temperature among all other items. I thought that CPU is the culprit.
But generally CPU is powered from PMIC( Power managment IC).
Does it mean that PMIC( Power managment IC) supplies higher current because CPU is faulty (shorted)
or PMIC( Power managment IC) is faulty but designed for a higher current so the temperature is lower than CPU?
Where would you search the short first? Would you replace PMIC( Power managment IC) first or CPU? Or any cappacitor?
Thanks for your suggestions
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What do you mean by drew some current? 1A?
I had a UAV with a shorted capacitor https://youtu.be/Bg7WEXm5usg (https://youtu.be/Bg7WEXm5usg)
Within ms it reach more than 150 °C
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It drew quite a low current but it did. And as a result the mobile could not start. So I need to find a short and I do not have a better idea than using FLIR. The CPU temperature was about 45C but it was the highest temperature there.
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If you expect the normal operating temperature of the CPU to be much lower than 45C, then the CPU is probably a culprit. You can try measuring the voltage and resistance on the power pins of the CPU to make sure it is being supplied the right voltage and that it's not shorted through the CPU. If voltages aren't correct, then there's probably a problem with the PSU and/or PMIC as well, and it wouldn't rule out the CPU being damaged. You have to use the other tools at your disposal, not just the thermal camera. Use all the info available and make some inferences as to which components are damaged.