I checked the jack and it appears to be fine: it looks fine visually and doesn't read a short between the power pins and the sense pin.Īt this stage, I asked the guy to try and source the original adapter, since I'm pretty sure he has a busted cable which no longer provides the sense pin, so the laptop just ran on battery until it completely died and then refused to charge. Although this one looks like it has 2K and a zener to at least protect the EC in this instance. Sometimes the jacks collapse and you end up getting 19V straight up the AD_ID pin into the EC. Safety measure as the cells are deemed faulty at that point.Īlso check DC Jack for damage, as there is a AD_ID sense pin going to the EC. I'm not sure what gets the battery to "output" again, because even after charging the cells themselves to around 11.3v, I get nothing on the red/black wires and as previously established, if I simply apply 12v to the battery terminal, nothing happens, probably because of lack of communication between the battery and the board.If the cells in the battery are completely discharged though, the controllers will refuse to charge them at all. The chip itself is probably not faulty, but simply refusing to turn on because of the ID pin in the charger. Looking on page 7 of the schematic, in the right pane, if I understand correctly, +3V_RTC is basically +3VPCU through D9, however +3VPCU comes from PU4 (page 29), but this is not happening. There's no coin cell on this board, which is typical of laptops with non-user-removable batteries. Presumably, this is from the coin cell battery so check if it's present Looking at this one, you have 3V_RTC on pin 7 which should enable it. Some battery controllers will disable the output pins until a logic line is grounded or has volts applied to it. I tried it with the bench supply most of the time, but also found an adapter from another HP laptop which fits the connector, however it could be there's some form of communication going on between the adapter and the board via that pin, so despite the adapter being and HP and matching the connector, it's STILL not enough ! What do you guys think ? Thank you. It could be because of the sense pin and the laptop is working fine, but simply refuses to charge, so it ran on whatever trickle of a charge it had left in it from when I powered its cells up. Is it the chip itself, or something else ? One time however, I noticed the light was staying on more than usual - the laptop was on and was displaying a picture ! It stood there for a good 30 seconds before shutting off on its own as if it was running on whatever charge it had left in the battery ! What's going on ? So, PU4 DOES work.but only when it feels like it and I have no idea what could be causing it. The same happens with my bench power supply (ignoring the "sense" pin): it doesn't draw any power at all on the DC jack. Ironically, SOMETIMES, God knows when and how, when I reconnect the battery, the orange light comes on ! Even more annoying, now all of a sudden I (obviously) DO get 3.3v (+3VPCU) on its coil (PL10), since I have a light ! It doesn't stay on forever though and it makes no difference if I plug in the charger NOW. This should be of no importance at this stage, since it should run without the battery, HOWEVER: Still, it wouldn't go through the connector, so the management chip in the pack is probably keeping it off. I took it one step further and peeled away the plastic film on the battery to expose the cells directly and NOW I was able to feed power into it directly, being careful not to pump too much current into it. I unplugged the connector and tried charging it on my bench supply but couldn't: it was taking no power through the connector. Interesting to note: the battery was completely flat. It's responsible for ALL power rails in the system and since none are coming on and I couldn't find any shorts, I'd blame it. Long story short, I think the problem is PU4, which is a BD99990Gu - an IC I couldn't find any info on. Other than that though, no other voltage comes on. I took some measurements and I do get 19v from the adapter coming into the board, so our main power rail +VIN is present. I took the cover off and noticed someone had been inside before, as two caps are missing (PC20 and PC29) which are just power-input filter caps, so it SHOULD work without those too. The laptop doesn't do anything: totally dead. I found the schematic AND boardview right here on our forum - big shout-out to SMDFlea for providing them ! It's been a while since I've worked on a laptop, but this one belongs to a very important person - my boss ! - so I'd be great if I could get this one going, but the signs are not good so far.
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