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. APO/FPO, Afghanistan, Alaska/Hawaii, Albania, Algeria, American Samoa, Andorra, Angola, Anguilla, Antigua and Barbuda, Argentina, Armenia, Aruba, Azerbaijan Republic, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belize, Benin, Bermuda, Bhutan, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, British Virgin Islands, Brunei Darussalam, Burkina Faso, Burundi, Cambodia, Cameroon, Cape Verde Islands, Cayman Islands, Central African Republic, Chad, Channel Islands, Chile, Colombia, Comoros, Cook Islands, Costa Rica, Cyprus, Côte d'Ivoire (Ivory Coast), Democratic Republic of the Congo, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Eritrea, Ethiopia, Falkland Islands (Islas Malvinas), Fiji, French Guiana, French Polynesia, Gabon Republic, Gambia, Georgia, Germany, Ghana, Gibraltar, Greenland, Grenada, Guadeloupe, Guam, Guatemala, Guernsey, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, India, Iraq, Isle of Man, Isle of Wight, Jamaica, Jersey, Jordan, Kazakhstan, Kenya, Kiribati, Kyrgyzstan, Laos, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Luxembourg, Macau, Macedonia, Madagascar, Malawi, Maldives, Mali, Malta, Marshall Islands, Martinique, Mauritania, Mauritius, Mayotte, Micronesia, Moldova, Monaco, Montenegro, Montserrat, Morocco, Mozambique, Namibia, Nauru, Nepal, Netherlands Antilles, New Caledonia, Nicaragua, Niger, Nigeria, Niue, Oman, Pakistan, Palau, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Puerto Rico, Republic of the Congo, Reunion, Russian Federation, Rwanda, Saint Helena, Saint Kitts-Nevis, Saint Lucia, Saint Pierre and Miquelon, Saint Vincent and the Grenadines, San Marino, Scilly Isles, Senegal, Serbia, Seychelles, Sierra Leone, Solomon Islands, Somalia, South Africa, Sri Lanka, Suriname, Svalbard and Jan Mayen, Swaziland, Taiwan, Tajikistan, Tanzania, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkmenistan, Turks and Caicos Islands, Tuvalu, US Protectorates, Uganda, Ukraine, Uzbekistan, Vanuatu, Vatican City State, Venezuela, Vietnam, Virgin Islands (U.S.Good day folks.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |