Dell Laptop AC Adapter Repair

It's not entirely unusual for switch mode supplies to 'hiss'.

There's likely nothing wrong with it at all. The noise is likely due to poor varnishing of a transformer btw but it doesn't affect operation.

Graham

Hello Graham,

The supply of our new Dell printer hissed since the first day. The problem is that the hissing continues all the way up to tens of MHz :-(

Of course, out here one has to check for other sources when hearing a hiss: Rattle snakes. Then there is the occasional pet that gets out, like a 15ft python here in Sacramento which is appropriately named "Miss Hiss". She ventured out into a warehouse next door twice. Since she wasn't volunteering to slither back home it took five guys to carry her.

Regards, Joerg

Have one Dell Laptop AC Adapter that is emitting hissing sound. A physical checkout does not reveal any burnt parts.

Model:PA-1900-05D PA-9 Family Manufacturer: LiteOn Input: 100-240V 50-60Hz 1.5A Output: 20VDC 4.5A Marking "CN-06G356-71615-432-061F Rev L04"

You don't mention whether the PSU is otherwise serviceable.

nothing is written on the casing on serviceable. but it is expensive RM160 (US$43)

=E4=B8=83=E5=B0=91=E7=88=B7SeventhPrince

He meant does it work aside from making the noise or is it dead?

Ebay....

jak

Are you aware that Dell had a recall on certain AC adapters. My daughter got a free replacement from them. Bob

I got 2 replacements. I think they were both the 70 watt adaptors though. Both were replaced with 90 watt adaptors.

Personally I wouldn't recommend trying to fix it (& I've been in electronics for 25+ years). They can be bought cheaply around Asia if necessary - I forgot to bring my adaptor with my notebook to Singapore recently, so picked up another adaptor in Sim Lim Square for under US$60 I think.

Dave

Methinks you got ripped off; most adaptors go for far less; check out Jameco (most of them are less than $30).

Blimey ! Yes.

We can get simple oem 'wall warts' for as little as $2.50. OK it's not a switcher and not say 30W but I'll guess they don't cost any more than say $6 to make.

Btw - the cable modem that came from my cable company was proudly emplazoned with the brand name *OEM* !

I guess they read the parts list, saw OEM power adaptor and assumed they had to 'brand' it as such ? I ought to post a pic in abse

Graham

switcher

These are 90 watts, and run on everything from 100V to 250V on even rubbish ship generator power. And are in a pretty small form-factor.

Dave

call tghe toll free tech support. report the problem.

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Have one Dell Laptop AC Adapter that is emitting hissing sound. A physical checkout does not reveal any burnt parts.

Model:PA-1900-05D PA-9 Family Manufacturer: LiteOn Input: 100-240V 50-60Hz 1.5A Output: 20VDC 4.5A Marking "CN-06G356-71615-432-061F Rev L04"

Any schematics that are available?

All advise is welcome. Thanks ???SeventhPrince

It's a switchmode power supply so normal troubleshooting techniques apply. Check for high ESR electrolytic capacitors, bad connections, shorted components, etc.

See the SMPS repair guide at the sites below, or as someone else said, order a replacement.

WARNING: Line powered switchmode power supplies can be deadly, make sure you understand the safety issues.

--- sam | Sci.Electronics.Repair FAQ:

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Several ppl have reported various Dell wall-warts and lump-in-a-cords that 'hiss'.

The noise can be caused by poorly assembled magnetics. It's not a 'fault' as such and Dell won't replace it.

Graham

Dell recalled a bunch of wall warts. Don't know the wart number, but it fit my CPiA-400. mike

Interesting.

You got a replacement just because it hissed ? If so, Dell have changed their policy.

Graham

You're inferring. What I said was that they recalled some wall warts. I never mentioned hissing. Mine had no symptoms at all. mike