Not charging, charged 1 time after replacing I/O board.

[Alku]

Hi,

A friends Macbook Pro got some wine on it and stopped working. I opened it up, cleaned everything and put it back together. It works now but doesnt charge (no charger light). I changed the I/O board and plugged it in. It charged now for a second (charger light went on) and then stopped. Plughed it in after some time again and it started charging. Charged full and then after unolugging it wouldnt start charging again... havent got it charging since then. I took it apart once more to ensure everything was fitted correctly. Also worth noticing that the I/O board was used not new. For me it seems like something burnt through at the I/O board after charging it... nothin visually seen. Anyone has some clue what could be the problem or what should i test next?

Thanks in advance,
Aleks

 

[real_mon2]

Review the bottom side markings of the enclosure. There should be an 'A***' number in this block of markings.

Which model do you have? If available, hunt for the 820-**** markings on the logic board but note that it will be somewhere on the black solder mask so a bit difficult to find.

This information will help to locate the schematics for this unit.

If the charger leg is not working, the fault may be related to the current sense circuits linked to the charger IC. This circuit consists of usually 3 resistors where the charger IC will monitor the voltage drop across a very low ohm resistor to gauge the current draw by the load (battery). If this current sense leg of resistors is broken (maybe a resistor is missing?) then the charger IC will assume that the voltage travels to the battery trace but then falls off due to lack of feedback from this current sense resistor so the load must be too high to support. Then the charging stops. This is only one scenario.

Would you have a multimeter? Hot air tools? Soldering iron? If possible, start a thread on the badcaps laptop forum and myself and other techs will try to assist you. Sounds like you have a magsafe interface and this is driven by the 3v42 power rail. The LED that is missing is based on a 1-wire protocol from Dallas / Maxim / Analog semiconductor. In your cleaning up of the wine, do use IPA (pharmacy grade) alcohol + cotton swabs to clean up all areas of the spill. Very important to avoid loss of PCB traces or worse. We recently saved a $3k macbook where there was a similar liquid spill but the owner was unable to clean all areas. There was an island of green corrosion that caused their charging to be intermittent.