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Groups > comp.sys.laptops > #1521

Re: How to open a Dell Power Supply/Charger

From davy <davy.5i3f5b@no.email.invalid>
Newsgroups comp.sys.laptops
Subject Re: How to open a Dell Power Supply/Charger
Date 2012-08-29 14:15 -0500
Message-ID <davy.5i3f5b@no.email.invalid> (permalink)
Organization NNTPGW
References <Ki_Image.5i1h2h@no.email.invalid> <ci4r38tcmooktckgbvkclb6cm49lb88jim@4ax.com>

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To open molded cases I uses a Dremel mini tool with either a cut off
disc or s mini saw blade, works a treat, take it easy running along the
seam... expect plastic dust so watch your eyes.

I usually Araldite them together afterwards leaving them held in a clamp
for a few hours.

I don't know about Dell, but the things I've repaired are usually either
switched mode power supplies or the good ol' wall warts with a
transformer, some are heat molded and yet some may have screws in the
base, usually concealed.

The switch-mode variety is usually capacitors that need replacing,
you'll see them bulged at the top or leaking gunge, which must be
cleaned off as it's very corrosive...

or they are usually blown to bits making repair not possible. What
happens here, is the capacitors fail, thus the feedback loop from the
isolated side to the live switched side goes ballistic, so the poor
transistor switches ON harder and harder until it self-destructs causing
major damage... this loop maintains regulation by altering the switching
drive's mark space ratio.

Always use *low ESR 105 deg. C* type capacitors should this be the case,
don't be tempted to use standard 85 Deg. types in switch-mode power
supplies.

Another way to open them is to use a fine hack saw.

DO REMEMBER INSIDE THESE SWITCH-MODE SUPPLIES THERE ARE LETHAL
VOLTAGES[/B] UNLIKE THE TRANSFORMER VERSIONS (AC LINE VOLTAGE X 1.414)
SO IN THE UK  WHICH IS AROUND 240V AC X 1.414 = APPX. 340V DC!!!!! [B]SO
ENSURE IT IS UNPLUGGED FOR ABOUT 5 MINUTES.

davy

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Thread

How to open a Dell Power Supply/Charger Ki_Image <Ki_Image.5i1h2h@no.email.invalid> - 2012-08-28 20:46 -0500
  Re: How to open a Dell Power Supply/Charger mike <spamme9@gmail.com> - 2012-08-28 20:49 -0700
  Re: How to open a Dell Power Supply/Charger AaronL <135sdf6738@fakiemail.com> - 2012-08-28 21:01 -0700
    Re: How to open a Dell Power Supply/Charger richgr@panix.com (Rich Greenberg) - 2012-08-29 15:53 +0000
    Re: How to open a Dell Power Supply/Charger davy <davy.5i3f5b@no.email.invalid> - 2012-08-29 14:15 -0500
      Re: How to open a Dell Power Supply/Charger mike <spamme9@gmail.com> - 2012-08-30 03:25 -0700
        Re: How to open a Dell Power Supply/Charger Couturier946 <Couturier946.5ji0pp@no.email.invalid> - 2012-09-26 03:46 -0500
          Re: How to open a Dell Power Supply/Charger mike <spamme9@gmail.com> - 2012-09-26 10:05 -0700
      Re: How to open a Dell Power Supply/Charger Ki_Image <Ki_Image.5i3zpg@no.email.invalid> - 2012-08-30 00:54 -0500

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