Hi Guys, I hope someone can assist me me. I have a HP Probook G2. It came in for not charging. When charger plugged in power light on the charge port was flickering as well as the caps lock light. Not a pattern, but inconsistent. I found a faulty mosfet on the power input which I replaced. Problem I have is that it does not start up without a battery unless I use a 18.5v charger. It does however start with the 19.5v with the battery installed, but the battery charge voltage is 2.58v. The required charger for this unit is a 19.5v of which I have tried several. The battery is bad and have ordered another. I have stable voltage on the 3.3v as well as the 5v now, after replacing the mosfet. Any ideas?
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Does this unit power up without a battery?
Use the original and recommended power adapter. The analog signal from the power adapter must be present to identify the power rating of this adapter. Confirm the power adapter connector.
Share the details of the charger ic. Check voltage of ACOK, REGN, acdrv if the charger ic is BQ type from Texas Instruments. -
No, The unit does not power up without the battery unless I use a 18.5v charger. I have tried with the orignal HP 19.5v charger which I have tested on another laptop and it is 100% working. What is strange, whith the 19.5v charger I get a voltage of 2.58 at the + pin on the batttery, but with the 18.5v charger is shows 11.8v. Charge voltage shoud be around 16v as it is a 4 cell 14.8v battery, or am I missing something?Comment
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Those are voltage measured on PU102Comment
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ACPRES 3.38v
ACDET 2.75v
ACDRV is 7.45v
Seems to be a BQ 736 Ti 471. A little difficult to read..Comment
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Measure ACN, ACP, ACDET and ACPRES on the charger ic with both adapters. There must be a difference.Comment
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What I am most worried about for now is the fact that the laptop will not switch on without the battery using the OEM power supply. Power light comes on for a few seconds then off. I thought it may be a BIOS issue, FLash a clean BIOS but with same result. Flashed original back.Comment
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If the laptop powers up with another power adapter then so should the OEM power adapter. After the OEM power adapter is used and led turns off, measure the above signals again. In the ‘off state'. It cannot be the bios if it works with the other power adapter.Comment
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Here's the thing...Any 18.5v charger switches it on OEM HP or comaptible...with or without battery. The 19.5v OEM charger does not switch it on without the battery. The spec as per HP for this laptop is 19.5v 2.31A. It is really strange, unless I have overlooked something basic.Comment
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What is the origin of the 19.5v OEM adapter? Supplied by HP with the laptop? It may be a fake otherwise. I know that I purchased one (intentionally) at the Wanchai computer plaza in HK because I am cheap. Vendor stated it was a fake but for $30 worth the risk and has worked for years to date.
Do monitor the adapter analog signal present on the very thin needle pin inside the round connector. Is it mating to the logic board ok? Check this voltage against the other adapters.Comment
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Hp OEM, it came with the laptop. I have a few here... There is only one brand of compatible PSU's that I would consider using, and they are from Astrum. They are expensive, but they work. Same with their laptop batteries. Charge port is perfect. No issues there. Like I said. Everything is stable with a 18.5v, but it is not supposed to be that way. Call me OCD, but right is right...I will work on the charging section when the replacement battery comes. My immediate issue is the startup with correct charger without battery.Comment
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Share the markings of dc-in mosfets or post a clear photo of that area. measure voltage on Source/gate/drain of dc-in mosfets.Check AD_ID voltage status with both adapters.Comment
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