HP 6730s notebook won't power up

[geob]

I have an HP 6730s notebook that has decided not to power up most of the time. This behavior has been going on for about two weeks. More precisely, the system will not power up if:

1. AC adapter connected to laptop, no battery in place, amber light flashes - either slowly or quickly.

or,

2. Fully-charged battery is installed, no AC connected, blue light goes on, amber may or may not flash.

or,

3. Either power source is connected, switch set to on, power up begins, hard disk light is amber, shuts down within 30 seconds.

From the power management guide:

● Turquoise: A battery is close to full charge capacity.

● Blinking amber: A battery that is the only available power

source has reached a low battery level. When the battery

reaches a critical

Yet the AC adapter is new 90 Watt. Battery is new OEM 8-cell Li-ion. Battery passes HP Battery Check and is reported fully-charged.

When these symptoms began the system also began displaying the message "Invalid serial number" during POST. The reference I think is to the system board serial number not the machine serial number.

I've spent over 10 hours researching this error to no avail. My leaning is toward replacing the system board but I'd really like to get confirmation that this is the only way to resolve the issue.

Any ideas?

Many thanks.

George

[allen2]

The invalid serial number might happen in at least two cases:

- if the bios battery is dying

- if a bad bios flash happened

So i'd try replacing the bios battery, and also do if needed a bios reset and then loading setup default should solve the problem.

[geob]

Thanks for the suggestion.

I've looked at the possibility the issue is related to BIOS and the RTC battery. I'd already re-flashed the BIOS with no change. BIOS also reported correct time and date so it's unlikely to be the battery. Besides, I'd have to get nearly as far as pulling the system board to replace the thing. If I do replace the board I'll replace the battery then. But the power up problems I don't think are related to the RTC battery. My best guess so far is that the system board has some failed components in its voltage detection circuitry. But I'd sure like it to be something I could fix without the expense of replacing the board. It seems like replacing the engine in my car because the air filter is clogged.

George

[Tripredacus]

I had a similar problem with a friend's notebook. We had taken it apart and tested it out and found that the DC connector on the power board was not showing the correct reading. After purchasing a new one (and getting someone to replace the part) we tested again and the power levels were correct, however the problem was not solved. We found that the problem existed even further into the circuit as well, but the choice of buying a new board vs risking component replacement came down to price vs risk and neither was worth it.

You problem may or may not be the same, but it could be as easy as replacing the DC connector. They can be had fairly cheap on eBay, however you'll also need to be comfortable working with lead-free soldering, which requires a lot more heat than your standard stuff you'd buy at a Radio Shack.

[geob]

Interesting idea, but my soldering skills are rusty, lead or not. Do I give my age when I say I built a Heathkit FM tuner?

I think I'll go for the system board replacement. I've pulled boards before so this should be no problem. As long as it makes the problem go away I'll be a happy camper.

Thanks again for the suggestions.

George