I need yours expertise to fix this
Im using Chinese 7 Ebook reader since 4 months. Yesterday I charged it and forgot to stop charging until 12 hr. after 12 hr. I removed it from the charger. Till then, it cant be turned on (no power at all, its dead). One or two times it came up but after 1min got down again. However, now it doent come up at all.
I removed the battery and kept 1or 2hr and tried to ON, but its still dead. Then I check the board. I found the power section is controlled by a little chip called PT1502 (data sheet attached herewith). According to it, as far as I could understand, when power button is pressed 3v-5v signal should come to the PT1502 in order to turn on the CPU. However, when I check, I found voltage on the above pin is around 2.51v. can this be a reason ??? I identified this voltage come to PT1502 through a SMD type FET (number is not printed). When switch is off, 4.07V come to the switch, but its dropped 2.51 when button is pressed. Can this happened due to a short-circuit on the FET or PT1502? Please give me a hint to respire this .
Im using Chinese 7 Ebook reader since 4 months. Yesterday I charged it and forgot to stop charging until 12 hr. after 12 hr. I removed it from the charger. Till then, it cant be turned on (no power at all, its dead). One or two times it came up but after 1min got down again. However, now it doent come up at all.
I removed the battery and kept 1or 2hr and tried to ON, but its still dead. Then I check the board. I found the power section is controlled by a little chip called PT1502 (data sheet attached herewith). According to it, as far as I could understand, when power button is pressed 3v-5v signal should come to the PT1502 in order to turn on the CPU. However, when I check, I found voltage on the above pin is around 2.51v. can this be a reason ??? I identified this voltage come to PT1502 through a SMD type FET (number is not printed). When switch is off, 4.07V come to the switch, but its dropped 2.51 when button is pressed. Can this happened due to a short-circuit on the FET or PT1502? Please give me a hint to respire this .
- Device: 7 e book reader (Chinese, brought from ebay)
- Li-iron cell : 3.7V 2000mAh ( Tested, its fully charged )
- please see the all attached files.
- Have you used PT1502 ?
- CPU : RK2738 Rockchip
- PCB: HTC-E001N

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