HP 510 SFF power problem

November 7, 2010 at 13:00:04
Specs: Windows XP, 2,4Ghz/1G
I have an HP 510 SFF desktop pc which just powered off when i was using it. i immediately noticed that the two gree light in from of the pc is on and stays on, not even the hard drive light was fluctuating the ways it used to normally. i pressed the power button to turn off the system, and turned it back on the two green lignt was green and on like before. I opened i the cpu and also noticed that the power fan and the processor fan is spinning constantly with the two front light green. i don't know what is the problem. I am suspecting the PSU,but don't have spare.\r\n
How do i trouble shoot this PSU?

See More: HP 510 SFF power problem

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#1
November 7, 2010 at 15:59:53
If it powered off and stayed off, that can commonly be caused by either

A power supply problem...
- common - a defective power supply
or
- common with SFF computers and brand name computers in general - you have installed a video card in a mboard slot that the existing power supply has not got enough capacity to handle.

Defective or overloaded power supplies often mis-behave for quite a while before the computer won't boot at all every time you try. Did you have intermittent symptoms before this ?

If you have installed a video card in a slot , you could try removing it and connecting the monitor to the onboard video port, but the PS may already be fried if it was overloaded when the video card was installed.

Have you installed a video card in a mboard slot ?
If so, which video chipset does it have ?

OR - your cpu has overheated - eventually the mboard will shut down, and it will NOT start up until the cpu has cooled to below some temp. In that case you just WAIT until the computer has cooled some, then it will probably start up.
When was the last time you checked to see whether there was too much dust and lint on the cpu fan and heat sink inside the case ?
.......

If your SFF mboard has a regular sized main power connector (20 or 24 pin) , it is a simple matter to try any ATX PS that has a 24 pin main connector and the proper second mboard and drive power connectors with your system - I'm assuming yours is 24 pin.
However, I found recently while t-shooting a SFF computer I suspected the PS had failed on that some SFF mboards including some of HPs have a MINI main power connector. I tried to find a mini 24 pin (male) to standard 24 pin (female) wiring adapter on the web - no such luck.

SFF PSs are almost always proprietary (oddball small sized enclosures ) and nearly always el-cheapo PSs made by minor brands.
El-cheapo PSs in general often fail because defective electrolytic capacitors were installed on their boards - they work fine for years, then the fluid inside the caps breaks down, the caps bulge on the top, they often leak fluid, and they can even EXPLODE.
My advice is, you need to open up the power supply box and look for such defective capacitors - if any are found, the PS is definitely in the process of failing. It isn't worth replacing the caps if there is a lot more than one made by the same company marking as as the one(s) that failed - you need to replace all of them made by that brand - and even if you replace all of the same brand, the PS may already be damaged such that it still cannot work properly, if your PS is not booting the computer all the way, every time you try now.
........

The following applies to mboards, but PSs can have defective capacitors too...

Some mboards develop this problem - electrolytic capacitors were installed on them that were not properly made, and they fail eventually - the mboard manufacturer didn't know they were improperly made at the time the mboard was made.

Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .

This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
http://members.datafast.net.au/~dft...

What to look for, mboard symptoms, example pictures:
http://www.badcaps.net/pages.php?vid=5
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
http://www.badcaps.net/

Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.:
http://www.halfdone.com/Personal/Jo...

.......

If your PS DOES have one or more bad capacitors, then you definitely need to replace it !

If you have installed a video card in a mboard slot....

Your power supply must have at least the minimum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD ! )
If that info is not in the ad for the video card, you can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements. Some power supplies have two or more +12v ratings - in that case, add those ratings to determine the total +12v current capacity.

If you're a gamer...
In most if not all cases, the max capacity rating of the PS is an intermittent rating. It's recommended that you do not load your PS to any more that 80% of that rating if you are going to be using something that puts a constant load on it, such as playing a recent game for hours on end. In that case, you multiply the min capacity stated for the system with the particular video chipset on the card by 1.25 to find the min. capacity of the PS you should get.
.....

If you use the HP part number that's on the PS to search the web with, you can often find a replacement PS that will fit inside the case that has a higher capacity than one it had. However, when I looked there were none that had a capacity higher than 300 or 350 watts.
......

As I said above - I tried to find a mini 24 pin (male) to standard 24 pin (female) wiring adapter on the web - no such luck.

If you want to make sure there's nothing wrong with the mboard and other components, BEFORE you get another PS, if your mboard DOES have the MINI main power connector socket - in my case it was 24 pin and shorter and narrower than a regular 20 pin one - you will probably need to do what I did....

(this is tedious but the result works fine...)

- if you have, in another computer you own, or have a spare one, or can borrow, a standard sized ATX 24 pin PS (20+4)....

- buy a standard 24 pin (female) to 24 pin (male) wiring adapter with standard sized connectors at a local place ( that you normally use to EXTEND the wiring of a PS that has a 24 pin main connector (or more commonly a 20 pin and a 4 pin connector in the same wiring bundle) for use in a 24 pin mboard socket mboard (23 or 24 positions wired up on the both ends))
- chop off the wires of that wiring adapter close to the 24 pin MALE connector (you don't need the MALE connector)
- chop off the MINI 24 pin connector's wires on the failing PS as far as you can from the connector
- bare the 23 or 24 or so wires for at least 1/2" both on the MINI 24 pin (MALE) connector's wiring and the standard sized 24 pin connector (FEMALE)
- if there are two wires at some positions in the MINI connector's wiring, ignore the smaller wire - it doesn't need to be connected to a standard PS
- you do NOT need to connect the white wire if that's present on the standard connector's wiring

- cut some 1" or so lengths of shrink tubing (2 - 3 times the diameter of the insulation on the wires) and slip them on all wires on one side -

- solder the pairs of wire ends together, using electrical solder , one by one, making sure the wires go to the same place in the connectors on both ends.

- use pliers to flatten any sharp places that you can feel on the soldered splices

- place the shrink tubing pieces over the soldered splices, one by one, centered - shrink it with a hair dryer set to max or with a heat gun (e.g. for stripping paint) set to a lower setting - be careful not to melt the tubing or the wire insulation - go slowly

Plug the (male) MINI 24 pin connector into the mboard, and the 24 (or 20 + 4) pin connector(s) into the 24 pin female connector of the wiring adapter, and plug the drive power connectors into the drives.

The mboard should then boot fine if there's nothing wrong.
........
Side notes -

A few months ago I repaired a Shuttle SFF computer . The computer had been failing to boot the computer intermittently, and when it did boot, it shut off the mboard when booting normally if the specific video drivers had been loaded in Windows, yet it worked fine, when it booted, if the specific video drivers were not installed, and in Safe modes and in Enable mode when they had been installed.

It has a propeitary small sized PS, but the mboard and other components are EASILY tested with a standard sized ATX PS because all their SFF mboards have a standard sized 24 pin main power connector.
In that case, I replaced two failed capacitors on the mboard, the ONLY ones of that brand, and the system has been working fine since.


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#2
November 7, 2010 at 18:25:42
I took a quick look on the web.
I don't know which HP part number your 510 PS has, but apparently it is definitely a really cheap el-cheapo, for the 510 series, 20 pin main connector, the only capacity I found is 250 watts.

a really cheap el-cheapo = it's cheap to buy, but it's a lot more likely it will malfunction

250 watts capacity - going by previous searching I have done , there very few video chipsets that require merely a 250 watt PS capacity, minimum.
(If you want to know which ones I found, I made list somewhere that I could dig up, when I was considering getting another PS for the Shuttle SFF computer)
I DO NOT recommend you install a video card in a slot on this computer, unless you CONFIRM that the video chipset requires merely a 250 watt PS capacity, minimum.

If you want to find out whether the mboard and components are okay before you buy a PS, then if your mboard has the MINI 20 pin main power connector, you're going to have to do similar to what I did, only you need a standard 20 pin female to 24 pin male wiring adapter (for using a PS with only a 20 pin connector with a 24 pin mboard socket) , or a 20 pin female to 20 pin male (extension) wiring adapter (you need the 20 pin female wiring connector) .


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#3
November 8, 2010 at 21:26:51
this is a general power problem, and i assum you don't understand the problem am explaining

The PSU has 14 pin not 20 or 24. any more help pls


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#4
November 9, 2010 at 06:02:21
Failing power supplies often partially work, fans and hard drives may spin, leds may come on, yet you may get no video and the mboard will not boot all the way.
Open up the box the power supply is in.
If it has defective capacitors you must replace the power supply.

Otherwise , there is no way of finding out whether your power supply is the problem that's better than trying a known good power supply.

According to what I found on the web, your power supply has a 20 pin main power connector - a double row, 10 each side. If the mboard has a regular sized 20 pin main power connector, if you don't want to take a chance buying a power supply until you're sure you need one, you can try connecting any regular ATX power supply to the mboard that has the right connectors for the drives (you may need two SATA power connectors) and the mboard (the 20 pin one, and possibly a smaller one or ones, 4 pin or 8 pin, or a pair of 4 pin).
......

The replacement power supplies I found cost only $50 or less , plus shipping. That's extremely cheap for a 250 watt SFF power supply, and HP would have paid even less. Power supplies that are that cheap are much more likely to malfunction.
........

If you have no video, you can't go into the bios Setup to see if the +3.3v, +5v, and +12v voltage readings are within 10% of nominal, or if any are zero.

You can buy a cheap, or more expensive, power supply tester device - but if your PS / mboard has the MINI main connectors, that won't plug into those. They indicate whether the +3.3v, +5v, and +12v voltages the PS is putting out are okay - if any voltages are not within 10% or zero, they will indicate that, and that indicates the PS is no good, but even if the voltages are okay, there can be other things wrong with the PS.
Example power supply testers
http://about.pricegrabber.com/searc...
Local places that have lots of computer parts often have one or more of those.

A standard sized 20 pin main connector socket on the mboard is a bit more than
1 11/16" long, 3/8" wide.
A MINI 20 pin main connector socket is shorter and narrower

You could use a voltage meter to test the voltages at the main connector - the main connector must be plugged into the mboard and the computer running - but you would need to know which voltages are where, and even if those are all okay, there can be something else wrong with the PS.

For more info, search the web using something such as: test computer power supply
and look at the "hits" .


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#5
November 9, 2010 at 07:59:15
POC. my power supply does not hav 20pin PSU socket it has 14, compared to ATX that has 24 check here for details

http://pinouts.ru/Power/compaq_pdp_...


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#6
November 9, 2010 at 09:31:22
Did you actually look inside the computer case at what the PS has, and/or use the HP part number on the PS to look it up ?

All HP computers have a Model number and a Product number on a label that's on the outside of the case somewhere.
What is it's Product number (a.k.a. Part number) ??

In any case, open up the box the power supply is in.
If it has defective capacitors you must replace the power supply.


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#7
November 9, 2010 at 11:06:54
The model of the PSU = HP-U176WF3

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#8
November 9, 2010 at 11:24:52
I suspect you have mis-quoted the computer model .

You probably have an older model than I looked for the power supply for.

When I search with HP-U176WF3 I find it's a.k.a. HP part numbers 274427-001 or 243891-002

When I searh the HP parts site withy 274427-001, it's mostly for the
Compaq Evo D510 Small Form Factor
series

All HP (and Compaq) computers have a Model number and a Product number on a label that's on the outside of the case somewhere.
What is it's Product number (a.k.a. Part number) ??

Article -
HP Compaq Evo d510 PDP117P 175-Watt PFC Power supply unit repair
http://webdevsys.com/d510psu.htm

same power supply


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#9
November 9, 2010 at 19:26:23
when i power it on, the two small led in front of the system is on and green, the PSU fan and the cpu fan are constantly spinning after power on, nothing displays on my monitor even when i remove all components like memory, ram, processor,no beep or anything happens except that the two small led in front of the system is on and green, the PSU fan and the cpu fan are constantly spinning after power on,

what step by step diagnosis can you provide me with now?


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#10
November 9, 2010 at 22:43:57
What is the computer's Product number (a.k.a. Part number) ??

You've already mentioned most of if not all of that - we've heard it all before - and I've already told you that failing power supplies often partially work, fans and hard drives may spin, leds may come on, yet you may get no video and the mboard will not boot all the way.

Open up the PS's box.
If it has defective capacitors (see response 1) , the PS is no good for sure - replace the PS. You may need to cut some wire ties in order to be able to see the tops of all the caps - one of more may even have exploded - in that case, the capacitor's "can" may not be there - there may be merely a pair of wires sticking out of the board, still soldered in, where the cap is supposed to be.
You may also see some other things are physically damaged.
If it smells like something has burnt inside of it, e.g. like the smell of burnt plastic, something has probably fried. (New power supplies may have a smell like that for a while but that goes away within a month or two.)
It's fan blade should move in jumps, but it should easily turn . If it is difficult to spin, or won't spin, the PS is probably damaged from overheating. Use something thin to try spinning it.

I've already told you in response 4 how you go about testing.

You can't use a power supply tester device because they are made to be used with standard 20 or 24 pin main power connectors.

Your only option is to use a voltmeter to test whether the proper voltages are there at the main connector, when the plug is plugged in and the computer is running. (see the pinouts link you provided) - some wiring connections are merely for signals - all the positions voltages are specified for should have the right voltage, within 10%, but even if they all do, there may be something else wrong with the PS .


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#11
November 10, 2010 at 04:08:54
let me first read the voltages, i'll let you know the values i get

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#12
November 10, 2010 at 07:52:51
What is the computer's Product number (a.k.a. Part number) ??

Have you opened up the PS's box yet ?
If you haven't, do that first, and examine it to see if it has any of the problems I told you of !
.......

You measure them with one lead on a ground connection - to one of the positions in the plug that has a ground wire preferably. You can usually get the tip of the meter lead probe in beside the metal end on the wire from the top of the plugged in main connector, and get a good connection.
.....

There is also the option, if you have or can borrow a regular ATX PS, of making yourself a custom wiring adapter (20 pin female to 14 pin male) that adapts the wiring of a standard 20 pin connector to suit your 14 pin one, since you have the info available about what voltage or signal is present at what position in your plug, and you can look up that info for a standard 20 pin one, but you would have to chop off the wiring of your main plug from the PS to do that.


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#13
November 10, 2010 at 22:57:48
i read the voltages with the PSU connected to the board and the system power button pressed, here is the result. I connected the ( - ) probe of Multimeter to the casing of the CPU and use the ( + ) probe to do the readings.

pin - voltages
1 = +3
2 = -12
3 = +1
4 = +2.4
5 = +5
6 = 0
7 = +12
8 = +3
9 = +3
10 = 0
11 = +5
12 = 0
13 = +5
14 = 0

compared to these values what does these reading indicate?


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#14
November 11, 2010 at 08:53:20
You should quote all the voltages that are not 0 to one decimal place, e.g. 3.3 v, 12.0 v

According to the link about the 14 pin connector you pointed to -

Pin Pin
Name Description
1 brown +3,3volts
2 blue -12v
3 violet fan off special pin
4 white power on-standby
5 green +5volts aux
6 white and red fan cmd special pin ( 3.3V RS- )
7 orange +12volts
8 brown +3,3volts
9 pink +3,3volts aux ( 3.3v RS+ )
10 black ground
11 red +5volts
12 black ground
13 red +5volts
14 black ground

Pins 3, 4, and 6 are for signals - what you read from those varies depending on circumstances - I have no idea what you should read from pins 3 and 6 if everything's ok.

Standard ATX PSs have two wires for signals in the main connector that are critical - PS_ON or Power on, and Power good a.k.a. Power OK or PS OK. Your wiring doesn't seem to have the latter.

A standard trick for testing a standard ATX PS is to try shorting the PS_ON or Power On wire to any Ground wire in the plug (e.g. you short it when there is no AC power connected to it, with a suitably bent metal paper clip), then the PS should switch fully on, and you should get +5v at the Power Good wire - but you don't appear to have a Power good signal wire, and the power on signal on your connector may be for something different.

(You can also try that when the PS is not plugged into the main connector on the mboard, but the ATX PS must have at least a minimal load on it in order for it to start up - e.g. at least a hard drive must be connected to it.)
.......

UPDATE - below the pinouts at the link you provided are these notes:

If you are converting from an ATX Power Supply Pin 6 and 3 are not needed.

Note:

Power-On on Compaq REQUIRES high signal to switch on!

Connecting directly power-on with power-on on standard ATX that start on low (connect to ground) won't be enough to start Compaq motherboard.
...........


All your other readings other than those are what they should be, or probably within 10% of nominal,
BUT, as I have said, even if all the voltages are okay, other things can be wrong with the PS.

Have you opened up the PS's box yet ?
If you haven't, DO THAT !

See response 10 and response 1 - check all the caps on the mboard too.
.....

Could there be something else wrong ?

Yes, but you haven't mentioned anything that leads me to believe that's a possibility, and failing power supplies are probably the most common reason a computer will not boot at all or will not boot fully.

If the connection of the power switch to the mboard is poor, or if the power switch is defective (extremely rare), then the PS may not start up properly. Make sure the connector for the power switch is not loose on the mboard pins for that. Briefly shorting the pins on the mboard for the power switch does the same thing as briefly pressing the button for the power switch.

A poor connection in it's slots of ram that worked fine previously can cause your symptoms.

A common thing that can happen with ram, even ram that worked fine previously, is the ram has, or has developed, a poor connection in it's slot(s).
This usually happens a long time after the ram was installed, but it can happen with new ram, or after moving the computer case from one place to another, and I've had even new modules that needed to have their contacts cleaned.

See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
http://www.computing.net/hardware/w...
......

If you have installed ram that was not installed in the mboard previously, not all ram is compatible with using it in your mboard, and in the worst cases of incompatibility, the mboard WILL NOT BOOT all the way when at least one incomaptible module is installed, and it often will not even produce an error beep.

It is easy to test for incompatible ram that has caused your mboard to fail to boot.
(This also works if your problem is caused by "bad" ram, but it's extremely unlikely it's "bad".)

Make sure you have a speaker or speakers or the equivalent connected to the mboard so you can hear mboard beeps (see your mboard manual if you need to).
Remove the AC power to the case/power supply.
Remove all the ram.
Restore AC power.
Try to boot.
If nothing else is wrong, you will get no video but you will hear a pattern of beeps that indicate no ram is installed, or a ram problem.
E.g. for an Award bios or a bios based on one, that's often a beep of about a half second, silence for a half second, a beep of about a half second, silence for a half second, continuously.
.....

Your mboard could have become defective - in that case, you will probably find it has failing or even missing electrolytic capacitors.


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#15
November 21, 2010 at 01:33:36
so what do i do to this mobo, change all capacitors?

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#16
November 21, 2010 at 10:03:34
It's a lot more likely
- for a power supply to be faulty than it is for the mboard to be faulty - say, 50 to 1.
- you have defective capacitors inside the power supply than you have them on the mboard, say, 20 to 1.

You haven't mentioned whether you have examined the capacitors in the power supply.

If you haven't already done so, see response 1, scroll down;. starting at
"The following applies to mboards, but PSs can have defective capacitors too...

If you don't see any failing - or missing - capacitors on the mboard, then it's extremely likely that there is nothing wrong with it.

Even if you don't see failing capacitors in the power supply, it's a lot more likely there's something wrong with the power supply.

If you DO see failing capacitors on the mboard, you should replace ALL of the ones that have the same brand marking, because they're just as likely to fail in the future if they haven't already. You will need a soldering iron with a lesser wattage rating - no more than about 25 watts, and electrical solder (e.g. 60% tin, 40% lead) - and some device to suck molten solder off with, and you may also need to drill out holes with a very small drill bit for holes you can't get the solder out of.
Personally I don't bother trying to replace failed capacitors on mboards unless there are only a few of them thsathave the same brand markingsas one or more that failed, and only if the mboard still allows the computer to work at least sometimes, because if it doesn't boot at all, it is a lot more likely it still won't boot after you have replaced the capacitors, due to something else being damaged.


If you need to replace many capacitors, it is probably going to cost you too much money to buy them locally.

Links on left to economical available premade or custom capacitor kits, and/or you can ship the mboard to him and he will replace the capacitors for a flat fee (including the capacitors) plus shipping (North America only).
http://www.badcaps.net/

If you're not in North America, there is a web site in Holland that does / has the same things.
.....

As I said above...

"There is also the option, if you have or can borrow a regular ATX PS, of making yourself a custom wiring adapter (20 pin female to 14 pin male) that adapts the wiring of a standard 20 pin connector to suit your 14 pin one, since you have the info available about what voltage or signal is present at what position in your plug, and you can look up that info for a standard 20 pin one, but you would have to chop off the wiring of your main plug from the PS to do that."

If you want to have the option of still being able to use the original PS after that, you could chop off the wires farther from the PS such that the wire ends can be soldered together again.


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