HP laptop Adapter and Audio Buzz zzz

[bhvm]

Hola amigos!

I have this beast laptop listed here-

http://www.techshout.com/laptops/200...16tx-notebook/

http://www.laptopviews.com/hp-laptop...6tx-laptop-pc/

The Adapter is rated for 19v at 4.7A...Which brings it to 90W.
I've noticed a faint, high pitched whine/buzz from the adapter.
Since this is from day 1....and has worked wonderfully for 4 years...I see that its not some fault...But by design. However that buzz is enough to irritate my sensitive ears, esp at quiet nights.
Can any of you explain in detail whats causing this noise? and how could i be eliminated? DELL adapter does not make any such noise.

Noise is at peak with NO load....and comes down as load applied. Sometime i can spot a Rhythm too (some component might be pulling power in the rhythm)

One More thing...Some electrical noise seeps in to the earphone socket, and can be clearly heard with earphones on but not on speakers. Its not the same Noise as adapter, but lower in frequency. I buyed some high quality (sensitive) Intra-aurals from Sony, Which made this problem worse.

What can be done?

[sofTest]

Re: HP laptop Adapter and Audio Buzz zzz

The buzz from the adapter is probably coil whine.

About the earphone noise, it's hard to say. It might be interference from other circuitry seeping into the earphone one. You might want to try an external USB-based sound card.

[bhvm]

Re: HP laptop Adapter and Audio Buzz zzz

You may be right about the coil. But what can be done to eliminate the noise? Any shielding? Will a big cap on output help?
I'm not in mood to spend for new audio card..... Lets think something.

[bhvm]

Re: HP laptop Adapter and Audio Buzz zzz

Hello again,
I just Isolated the ground.
Simpley taped the top Prong on the plug.. and the noise went away!

Sometimes, My lap gives me a very small shock at the front speaker grill tough... Ohh!!

[delaware74b]

Re: HP laptop Adapter and Audio Buzz zzz

The small shock your received is from the ground being isolated. Most laptop chargers are SPMS(switch mode power supply) and generate a high voltage during normal operation. The fact that you got a shock indicates there may be a voltage leak in that power supply. My advice is to remove the tape off the grounding pin and repair or replace that supply.

[bhvm]

Re: HP laptop Adapter and Audio Buzz zzz

laptop adapters ARE SMPS.

Thanks for the suggestion.
I'll get it repaired.

Problem is, its pasted Fit... Opening it is more like breaking it!

[insomnia]

Re: HP laptop Adapter and Audio Buzz zzz

seen this problem alot with hp chargers best thing to do is replace it

[MapleS]

Re: HP laptop Adapter and Audio Buzz zzz

The small shock your received is from the ground being isolated. Most laptop chargers are SPMS(switch mode power supply) and generate a high voltage during normal operation. The fact that you got a shock indicates there may be a voltage leak in that power supply. My advice is to remove the tape off the grounding pin and repair or replace that supply.

yeah, its right.so you can do it at first.
The laptop electrical system has circuitry that senses when the power fluctuates, or is outside of the normal range, and then switches power to the battery. Not sure if you have the tools, but any multimeter will have the functionality to test the output of the powerbrick.

[yyonline]

Re: HP laptop Adapter and Audio Buzz zzz

If you do replace it, make sure to replace it with a genuine part. A lot of these generic replacement A/C adapters are downright dangerous, lacking safety certifications, forged certifications, missing protection circuitry, etc.

[bhvm]

Re: HP laptop Adapter and Audio Buzz zzz

Funny thing.
In my personal Experience that HP genuine stuff is low quality.

I.ve paid top dollar for my HP DV8000, But the battery went bam in 10 months. DVD RW left me in 18 months. The Cooling fan Died in 3 years. Just replacing these with 'gernic' components solved the frustration. (And HP never entertains their warranty as these are 'consumable items'

Have a nice day!

[yyonline]

Re: HP laptop Adapter and Audio Buzz zzz

Funny thing.
In my personal Experience that HP genuine stuff is low quality.

I.ve paid top dollar for my HP DV8000, But the battery went bam in 10 months. DVD RW left me in 18 months. The Cooling fan Died in 3 years. Just replacing these with 'gernic' components solved the frustration. (And HP never entertains their warranty as these are 'consumable items'

Have a nice day!

HP laptop power adapters are usually either Lite-On or Delta units, same as every other major manufacturer out there. Lite-On and Delta PSUs don't always use the best components out there, but the designs are such that they won't overheat and catch fire...the same can't be said about some of the generic power adapters I've seen out there. See: http://www.electricstuff.co.uk/acadapter.html for a dissection of a generic "for Dell" power adapter.

HP hardly makes any of the components in their laptops, they just screw them together. Likewise for their optical drives and fans... All the major laptop manufacturers source these components from the same sources as all the other major laptop manufacturers. So in theory, they should all have similar reliability.

Batteries are considered consumable items under any manufacturer's warranty, but the other devices should have been replaced, provided they died within the warranty period.

[MapleS]

Re: HP laptop Adapter and Audio Buzz zzz

The buzz from the laptop ac adapter is probably whine.

About the earphone noise, it's hard to say. It might be interference from other circuitry seeping into the earphone one. You might want to try an external USB-based sound card.

The laptop will only draw what it needs. If for some reason the laptop failed with a short it could draw a lot more power and do a lot more damage with the higher current supply. If that bothers you install a 2.5amp fast blow fuse inline with the positive lead.