I have an 820-4924 that was liquid damaged the computer will run both off the charger and the battery just fine. When you plug in the charger with the battery plugged in it will never give a green light. with the battery unplugged it will randomly get a green light after a few times of unplugging and re-plugging. with the battery in dc in is at 2.2 volts on the fuse. with the battery out dc in ranges from 3v to .3v then will just spike to 16.5 after the green light comes on. if the battery is connected after the green light is on the charger the battery will charge just fine till full and will stay charging unless unplugged. then after re-plugging it in it will again fail to get a green light. I have no clue where to start with this because of the seemingly complete randomness.
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820-4924 wont charge battery intermittent green light
- Thread starter Gannons3
- Start date
PPBUS_G3H is created by Q7130 sending pulses of the charger voltage through. Some 16v, some 0v. Some 16v, some 0v. It is supposed to average out to 12.56v through L7130.
If Q7130's top transistor shorts and gets stuck, it will not switch. PPBUS_G3H will permanently be 16v. The battery does not like 16v. Sending 16v to the battery will cause it to go poof. To prevent this from happening, the system shuts down the charger when it senses the battery plugged in and being given 16v.
So,
1) What voltage is PPBUS_G3H when battery is not connected?
2) IF and only IF PPBUS_G3H is 12.56v or 12.23v, does it work with a KNOWN GOOD battery?
If Q7130's top transistor shorts and gets stuck, it will not switch. PPBUS_G3H will permanently be 16v. The battery does not like 16v. Sending 16v to the battery will cause it to go poof. To prevent this from happening, the system shuts down the charger when it senses the battery plugged in and being given 16v.
So,
1) What voltage is PPBUS_G3H when battery is not connected?
2) IF and only IF PPBUS_G3H is 12.56v or 12.23v, does it work with a KNOWN GOOD battery?
My best guess there is the battery is pulling down the SMC data line or is bad. Try another battery. U7100 communicates with U5000 on the same data line it uses to communicate with the battery. If it is pulled down, U5000 will not be able to tell U7100 to up the PPBUS_G3H voltage to 12.56v from 12.23v.
USe diode mode on the meter and measure both R5381 and R5380 with red probe on ground, black probe on pin 2 of the resistor. What do you get for each? 12.23v at any time means something going on with this data line.
That sounds fine. Are you getting 12.56v on PPBUS_G3H after replacing the ISL6259?
If R7010 is hot enough to burn you then the most likely case is that PP3V42_G3H is missing as this is part of the circuit for the PP3V42_G3H power supply. PP3V42_G3H is the first rail that must show up before PPBUS_G3H is present. So my first question would be, do you have a short to ground where D7010 is? Our focus should shift to solving a potential PP3V42_G3H issue before going back to the PPBUS_G3H issue.
.141 in diode mode is not a short on PPBUS_G3H, but rather exactly as it should be.
.141 in diode mode is not a short on PPBUS_G3H, but rather exactly as it should be.
If you had 12.23v before replacing the ISL and have half a volt after then it is clear that something happened there. Either bad ISL or bad soldering. The original issue was bad communication between the SMC and the battery. This is caused by bad pullup resistors, bad SMC, or something on the line shorting that data line to ground.
Now there are an entire whole host of other issues that I can't begin to imagine over text vs. seeing it.
PP3V42_G3H should be 3.42v, not 3v.
From what you have said the second time you soldered the ISL6259 something had to have gone wrong enough to pull down PP3V42_G3H and cause PPBUS_G3H to disappear entirely.
Now there are an entire whole host of other issues that I can't begin to imagine over text vs. seeing it.
PP3V42_G3H should be 3.42v, not 3v.
From what you have said the second time you soldered the ISL6259 something had to have gone wrong enough to pull down PP3V42_G3H and cause PPBUS_G3H to disappear entirely.