Standard Vdc output w/BSOD?

Terrible question, but necessary since I'm not an AC/DCexpert. Would a laptop power adapterconnected to a laptop that would only boot to the BSOD, not to Windows 7, be expected to produce a lower voltage output thannormal (15.1 Vdc vs the listed 18.5 Vdc)?Or should a power adapters always produce the same Vdc outputregardless of whether the laptop boots to Windows, BSOD or even had the OS installed at all?

Adapter Specifications:
65W/50-60 Hz
Input: 100-240V~1.7A
Output: 18.5V/3.5A

*The laptop's PSU/rechargeable battery had also been removed atthe time of the Vdc reading, if that makes any difference.
**I believe the exact BSOD error was 'A problem has been detected and Windows has been shut down to prevent damage to your computer...'
Apologies and thanks in advance for any and all input and assistance!

essiesc said:

Terrible question, but necessary since I'm not an AC/DCexpert. Would a laptop power adapterconnected to a laptop that would only boot to the BSOD, not to Windows 7, be expected to produce a lower voltage output thannormal (15.1 Vdc vs the listed 18.5 Vdc)?

Not at all.

A power adapter is just that. It has no knowledge of what it is connected to. It doesn't even know it is connected to a computer, let alone what it is doing. The only thing that matters is the load. The higher the load, the lower the output voltage. Of course with a regulated adapter the difference will be very small.

The difference between a computer in a BSOD or operating normally in an idle state is just a different state of the software. Both are low power states with low power load. I wouldn't expect any significant difference in power requirements or differences in voltage. If the computer were in active operation the power requirements would be higher with a correspondingly lower voltage. But with a regulated adapter, not much.

LMiller7 said:

Not at all.

A power adapter is just that. It has no knowledge of what it is connected to. It doesn't even know it is connected to a computer, let alone what it is doing. The only thing that matters is the load. The higher the load, the lower the output voltage. Of course with a regulated adapter the difference will be very small.

The difference between a computer in a BSOD or operating normally in an idle state is just a different state of the software. Both are low power states with low power load. I wouldn't expect any significant difference in power requirements or differences in voltage. If the computer were in active operation the power requirements would be higher with a correspondingly lower voltage. But with a regulated adapter, not much.

Hm. So could you tell me if the following statements would be correct? I don't think this is a normal situation, and I was in the room when this testing took place, and have photos taken with calibrated test equipment as well, I'm just having a bit of trouble putting the entire picture together. Again, my apologies for my ignorance.

A) An unregulated power supply should be matched as closely as possible to the voltage and current requirements of the device it is powering; also the output voltage of the PSU should decrease as the output current increases, and vice versa.

B) The adapter in question must be unregulated given the fairly significant difference in the output reading (18.5 vs 15.1). Unless a defect in the adapter could cause a difference of that size?

C) The laptop in question had the same test performed a second time, except the second time, the Operating System had been restored, and Windows booted normally (no BSOD).

In idle state, the adapter produced a result as expected, 18.5 Vdc, but it also had the battery pack installed, and multiple programs running.

Since the adapter should not have a large difference between a BSOD and an idle Windows 7 OS, would I then be able to rule out whether the defect was in the adapter if I tested the Vdc with and without the battery in the laptop? Or would a lower reading without the (fully charged) battery not be a good indicator?

Thank you again for your assistance, I very much appreciate it!

fireberd said:

I think you are relating voltage to other system problems or non problems. Since the system works OK after reinstall the BSOD was a problem with the software and not the power.

Whether the 3V drop is expected? I would not think it was unless an excessive amount of current was being drawn from the PC/Battery.

Bottom line if it works, do not try to "fix it".

(I am an electronics and computer tech - also a guitar amp tech).

I think you're misunderstanding this issue. While the system "works" after reinstall, the adapter continues to malfunction, and heat to the point of boiling/burning.

Thought it might be a battery issue, but purchased a brand new, brand manufactured battery and same problem occurs. Can't exactly pinpoint which software causes the most overheating, seems to be an issue with this particular laptop, and internet seems to be a factor, according to HP message boards, but speaking to another electrical engineer from Honeywell yesterday, I think the adapter could definitely be defective.

(I am also in tech, EMC, NASA, etc, just haven't worked on the electric or AC/DC side before. Thanks very much for your comments, I very much appreciate it.)