Pavilion 520n No Power - PLEASE HELP!

d

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Was working fine last night, woke up this morning & my pc was off so I
attempted to power on as usual except when I pushed the power button,
nothing happened. I even held it in for a few seconds & still nothing.
I did notice in the back right next to where the power cable plugs into
the pc that a green light was lit so there's power going to the pc, I
just can't turn the thing on with the power button. I then opened the
box & cleaned everything with a can of air but still....NOTHING. Does
anyone have any significant suggestions? Thanks in advance.
 

d

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What I've done so far: I left the unit unplugged all day..used a brand
new power cable & plugged back into a different outlet (no surge
protector), reseated the memory, the video card, reseated the power
button wiring where it attaches to the board. Took the cmos battery out
then replaced back into compartment. Flipped the red voltage switch
then back to american voltage. Still no power, I DID however notice
both fans turned when I pushed the power button but ONLY once after a
re-attachment of the power cable. To see the fans move, you have to
disconnect the power cable then re-connect & the fans will turn once
when pushing the power button. I still have a green led light on the
power compartment on the back. But no powering up from the front. Most
of you mentioned replacing the power supply box...it didn't look
simple...is the wiring the same for all power boxes? In other words,
will I have the same amount of wires running to my drives & board etc.?
Thanks again in advance!


Ben Myers wrote:
> How about unplugging it from the wall current for a while? Sometimes the cheap
> power supplies get a little constipated, and unplugging them flushes them out.
> If that fails, it's time to try another power supply first, then see if the
> motherboard is hosed, etc... Ben Myers
>
> On 1 Sep 2005 10:26:18 -0700, "D" <MuzicNme@aol.com> wrote:
>
> >Was working fine last night, woke up this morning & my pc was off so I
> >attempted to power on as usual except when I pushed the power button,
> >nothing happened. I even held it in for a few seconds & still nothing.
> >I did notice in the back right next to where the power cable plugs into
> >the pc that a green light was lit so there's power going to the pc, I
> >just can't turn the thing on with the power button. I then opened the
> >box & cleaned everything with a can of air but still....NOTHING. Does
> >anyone have any significant suggestions? Thanks in advance.
> >
 
G

Guest

Guest
Archived from groups: comp.sys.hp.hardware (More info?)

How about unplugging it from the wall current for a while? Sometimes the cheap
power supplies get a little constipated, and unplugging them flushes them out.
If that fails, it's time to try another power supply first, then see if the
motherboard is hosed, etc... Ben Myers

On 1 Sep 2005 10:26:18 -0700, "D" <MuzicNme@aol.com> wrote:

>Was working fine last night, woke up this morning & my pc was off so I
>attempted to power on as usual except when I pushed the power button,
>nothing happened. I even held it in for a few seconds & still nothing.
>I did notice in the back right next to where the power cable plugs into
>the pc that a green light was lit so there's power going to the pc, I
>just can't turn the thing on with the power button. I then opened the
>box & cleaned everything with a can of air but still....NOTHING. Does
>anyone have any significant suggestions? Thanks in advance.
>
 
G

Guest

Guest
Archived from groups: comp.sys.hp.hardware (More info?)

Ouch! "Flipped the red voltage switch then back to american voltage." Where is
this system? It was sold in the US and Canada, according to the HP web site.
Does this mean that you plugged the computer into the wall with the voltage
switch set to 220v? I am not sure what are the effects of running 110v into a
power supply set to accept 220v. Surely less serious than the other way around.

The 520n has an Intel 810 chipset and it runs a fast Celeron chip, so any ATX
power supply will do for the purpose of testing. First, disconnect the power
cables and data cables from all peripherals. The attach the replacement power
supply to the ATX connector on the motherboard. See if it powers up. If it
does, the odds are real good that the original power supply is the culprit.

You may find that the HP power supply has different physical dimensions than one
of the standard sizes. It may also have a connector to the motherboard to
control the fan iside the power supply. This is somewhat non-standard, too.

.... Ben Myers

On 1 Sep 2005 19:30:53 -0700, "D" <MuzicNme@aol.com> wrote:

>What I've done so far: I left the unit unplugged all day..used a brand
>new power cable & plugged back into a different outlet (no surge
>protector), reseated the memory, the video card, reseated the power
>button wiring where it attaches to the board. Took the cmos battery out
>then replaced back into compartment. Flipped the red voltage switch
>then back to american voltage. Still no power, I DID however notice
>both fans turned when I pushed the power button but ONLY once after a
>re-attachment of the power cable. To see the fans move, you have to
>disconnect the power cable then re-connect & the fans will turn once
>when pushing the power button. I still have a green led light on the
>power compartment on the back. But no powering up from the front. Most
>of you mentioned replacing the power supply box...it didn't look
>simple...is the wiring the same for all power boxes? In other words,
>will I have the same amount of wires running to my drives & board etc.?
>Thanks again in advance!
>
>
>Ben Myers wrote:
>> How about unplugging it from the wall current for a while? Sometimes the cheap
>> power supplies get a little constipated, and unplugging them flushes them out.
>> If that fails, it's time to try another power supply first, then see if the
>> motherboard is hosed, etc... Ben Myers
>>
>> On 1 Sep 2005 10:26:18 -0700, "D" <MuzicNme@aol.com> wrote:
>>
>> >Was working fine last night, woke up this morning & my pc was off so I
>> >attempted to power on as usual except when I pushed the power button,
>> >nothing happened. I even held it in for a few seconds & still nothing.
>> >I did notice in the back right next to where the power cable plugs into
>> >the pc that a green light was lit so there's power going to the pc, I
>> >just can't turn the thing on with the power button. I then opened the
>> >box & cleaned everything with a can of air but still....NOTHING. Does
>> >anyone have any significant suggestions? Thanks in advance.
>> >
>
 

d

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The red voltage switch located here:

http://h10025.www1.hp.com/ewfrf-JAVA/Doc/images/c00367399.jpg

This is just what I did: With the power cord removed, flip the red
voltage selector switch (figure 1) to the opposite position (usually
located under or beside the power cable plug on the rear of the
computer). Wait about five seconds, and then switch the red voltage
selector switch back to its original location.

Verify that the red voltage selector switch is switched to 115V for
North America or to the proper voltage used in the country/region.

I pretty much followed all these directions to no avail.
http://h10025.www1.hp.com/ewfrf/wc/document?dlc=en&lc=en&product=70999&lang=en&cc=us&docname=bph06788

I will try another power supply & test. I have a spare that I can try &
I have a spare from a compaq.
 

d

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No I haven't added any new accessories...I did install an ati all in
wonder vid card about 2 years ago but everything ran excellent until
now. Here's the good news.... I'm getting somewhere...I unplugged all
the drive connections just to see if there was a short somewhere but
still no power SO...I borrowed a power supply box from a compaq, hooked
up the main power connection on the MB & low & behold..the thing
powered right up. Am I to assume it's indeed the power supply? If so I
need to buy one that fits my unit because the compaq supply was too
large in physical size. Thanks.
 
G

Guest

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Archived from groups: comp.sys.hp.hardware (More info?)

Whew! OK. Without the power connected... Ben

On 2 Sep 2005 08:23:35 -0700, "D" <MuzicNme@aol.com> wrote:

>The red voltage switch located here:
>
>http://h10025.www1.hp.com/ewfrf-JAVA/Doc/images/c00367399.jpg
>
>This is just what I did: With the power cord removed, flip the red
>voltage selector switch (figure 1) to the opposite position (usually
>located under or beside the power cable plug on the rear of the
>computer). Wait about five seconds, and then switch the red voltage
>selector switch back to its original location.
>
>Verify that the red voltage selector switch is switched to 115V for
>North America or to the proper voltage used in the country/region.
>
>I pretty much followed all these directions to no avail.
>http://h10025.www1.hp.com/ewfrf/wc/document?dlc=en&lc=en&product=70999&lang=en&cc=us&docname=bph06788
>
>I will try another power supply & test. I have a spare that I can try &
>I have a spare from a compaq.
>
 
G

Guest

Guest
Archived from groups: comp.sys.hp.hardware (More info?)

On 1 Sep 2005 19:30:53 -0700, D <MuzicNme@aol.com> wrote:
> What I've done so far: I left the unit unplugged all day..used a brand
> new power cable & plugged back into a different outlet (no surge
> protector), reseated the memory, the video card, reseated the power
> button wiring where it attaches to the board. Took the cmos battery out
> then replaced back into compartment. Flipped the red voltage switch
> then back to american voltage. Still no power, I DID however notice
> both fans turned when I pushed the power button but ONLY once after a
> re-attachment of the power cable. To see the fans move, you have to
> disconnect the power cable then re-connect & the fans will turn once
> when pushing the power button. I still have a green led light on the
> power compartment on the back. But no powering up from the front. Most
> of you mentioned replacing the power supply box...it didn't look
> simple...is the wiring the same for all power boxes? In other words,
> will I have the same amount of wires running to my drives & board etc.?
> Thanks again in advance!

Have you changed any accessories. HP power supplies are overrated
(nowhere near their rated output).

I had a similar problem after installing a different video card on my HP
a530n (FX 5700LE in place of standard FX 5200XT). When I pressed the
power button, the light would come on for an instant and then go out,
until the plug was pulled and reinserted. Apparently my HP 250w power
supply could not even handle 125w. I installed an Antec SmartPower 350
and all was well, even after using eVGA's trade up policy to upgrade the
FX 5700LE to 6800 (much faster video).
 
G

Guest

Guest
Archived from groups: comp.sys.hp.hardware (More info?)

I'd say you are getting somewhere. Now, just to be sure, attach the power and
data cables to hard drive(s), CD or DVD drive(s), floppy drive, and test again.
If the system runs like it did before, the old power supply has failed, so
replace it... Ben Myers

On 2 Sep 2005 18:01:12 -0700, "D" <MuzicNme@aol.com> wrote:

>No I haven't added any new accessories...I did install an ati all in
>wonder vid card about 2 years ago but everything ran excellent until
>now. Here's the good news.... I'm getting somewhere...I unplugged all
>the drive connections just to see if there was a short somewhere but
>still no power SO...I borrowed a power supply box from a compaq, hooked
>up the main power connection on the MB & low & behold..the thing
>powered right up. Am I to assume it's indeed the power supply? If so I
>need to buy one that fits my unit because the compaq supply was too
>large in physical size. Thanks.
>
 

d

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Looks like it was indeed the power supply, things have been running
smooth for the past few days. PC is quieter also. Thanks to all for the
tips.
 

jawarren00

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Oct 28, 2012
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these units are very subject to power supply failure. the power supply is only 145W.

always remember that modern electronics aren't ever completely shut off. they use what is called a
soft off, where even though you power off, the system still is drawing some power. the only way to completely shut off the system is to disconnect the power from the outlet.

there are several replacement power supplys for this unit. it is mATX power supply, and can be upgraded
to about 250W. I have the same model, and replaced the power supply for about $50 about 5 years ago. you can get the original wattage, but i dont suggest it because it is too small to drive all of the components in the system.

 

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