In August 2007 I bought my first modern laptop, an HP dv6000m with specs about like this:
- Genuine Windows Vista Home Premium
- Intel(R) Core(TM) 2 Duo T5600(1.83GHz/2MB L2Cache)
- 15.4" WXGA BrightView Widescreen (1280x800)
- Intel(R) Graphics Media Accelerator 950 - Core
- 2GB DDR2 System Memory
- 200GB 5400RPM SATA Hard Drive
- LightScribe Super Multi 8X DVD+/-RW w/Double Layer
- Intel(R) PRO/Wireless 3945ABG Network Connection
- 6 Cell Lithium Ion Battery
There are ALOT of similar HP laptops that I believe suffer from the AC Power Adapter issue that I'm about to describe below (in fact I believe that any HP laptop from this era could be subject to this problem, it's just hard to say).
The tricky part about this problem is that its symptoms do not reasonably lead even a savvy user, like me, to the direct cause. The first day I started using my laptop I noticed a strange non-constant background buzzing sound that seemed to be coming from the speakers. (I will clarify that everyone's idea of a buzz is different and that the sound I'm describing could be called a whine, squeal, or squeek as well). The difference with this sound was that it was not coming from the OS. After turning the volume all the way down in the operating system, the high pitched buzz remained. The buzz was also present in the Line/Mic in signals as well as the Headphone output.
Naturally, this was annoying. But it's not the kind of issue that you send your laptop back to the manufacturer for (and wait 8 weeks in the interim). All in all, it wasn't THAT loud and if you had music or other audio playing it was essentially inaudable. I searched around on the internet in '07 and '08 and found that numerous other people were experiencing similar issues with their recent model HP laptops. It just didn't add up; how could HP not realize that their laptops, or a percentage of them at least, were buzzing whenever they were on?
For the next two years, I accepted the noise and largely forgot about it. It wasn't until about a month ago (July 2010) when the same issue began to manifest itself in another way. Ever since the thermal sensors went out on my IBM Intellistation desktop, my 1080p 23" monitor had been sitting dormant in my room getting no use, so I decided to start using my laptop to drive the display. When I plugged the external monitor in to the laptop (VGA cable) I instantly saw tons of horizontal scanlines jumping all over the display. After a few moments of study and careful listening, I noticed that the scanlines seemed to correlate and move in relation to the high pitch buzz which was still present. Both Windows 7 and Ubuntu 10.4 behaved identically in this regard.
Again, I took to the internet to see if anyone else had ever experienced such a thing before. Sure enough tons of the same people with the buzzing sound issue had the flickering external monitor issue as well, go figure. Fortunately by this time, someone had devised an inconvenient work around: drive the display on battery power. Once the laptop was unplugged from the wall, the flickering and scanlines instantly went away! What a miracle, I could finally use my screen, but it wasn't convenient and desktop-like as I had hoped. The laptop constantly had to be charged, and I couldn't just leave it on for extended periods of time. There had to be a better way, but at this point, I was happy enough and decided to give it a rest
As they say, luck finds you in the most mysterious ways…Not more than 2 weeks after my battery workaround discovery, did I notice that my official OEM HP branded AC Power Adapter [link broken] had been apparently chewed through. While I cannot confirm how it happened I will say that the frayed adapter was toast (and I was without a laptop for a week). If you clicked that link in the last sentence, you'll see that HP wants the outrageous price of $59.49USD + S&h (and that's even with a $10.50 instant rebate!). Now as a reasonable individual I happen to know that the fine folks over in the People's Republic of China produce notebook power adapters for every laptop ever made and they DON'T over charge for them (fancy that…).
A quick jaunt over to Amazon found me this little puppy: NEW AC Adapter/Power Supply+Cord for HP Pavilion DV2000 dv1000 dv4000 dv5000 dv6000 dv8000 ze2000. As you can see, the total price including shipping comes in at around $10USD.
When it finally arrived in my mailbox (2 days earlier than quoted even!) it was a blessing in disguise. After plugging it in to power the laptop, I noticed that magically, some how, both the audio buzz AND the monitor flicker were no more! The problem all along was HP shipping (some of?) their laptops with defective power adapters.
Upon making this realization, I figured it would be worthwhile to share it with the world, so here it is: The power adapter makes a difference! I'll say that again: the power adapter makes a difference! Ironically, in this case, the knock-off power adapter performed more reliably than the OEM one ever did. Which just goes to show you, you don't always get what you pay for.
When it comes to electronics accessories, it is my personal belief, that there is nothing more overpriced and overrated than name brand cables and adapters. For cables, if they're digital signals (USB, 1394, HDMI) and shielded, they're good enough. I've personally bought two $7USD 6' HDMI cables which work flawlessly. I don't even know if you can get ANY HDMI cable at radioshack or the like for under $10, especially not a six footer.
I'm not sure what the moral of the story is, but its a mix between manufacturers cheaping out on OEM parts, lack of effective support and recall for widespread problems, and realizing that a power adapter issue can even cause the kinds of symptoms described above…ultimately however: keep your eyes open, and when troubleshooting always start from the ground up!