[911pchelp]

Friday it took several tries before PC turned on (no problems previously - no hardware changes had been made). I turn PC off each night - I am only one who uses it - PC is at home.

Saturday PC wouldn't power on for many tries ... finally did - ran with no problem from 2 PM to 2 AM.

Sunday PC wouldn't EVER power on. Tried periodically thru the day.

(PC: Dell Insperion 545 desktop with 6 GB RAM, 350 GB HDD, 1 TB Ext USB, Win 7 ... 3 yrs old).)

Pwr Btn has a light (probably an LED) in it which lights when the btn is depressed, but the light indicating HDD activity never comes on (no fan turns on either).

Would a bad Pwr Supply cause this? What about the Bios//DateTime battery?

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Hello 911pchelp

A bad power supply is the most likely cause of the issue, this includes the PSU itself having failed or a bad connection, one thing that does help point more to a bad PSU is error beeps or the lack of any being heard, if the computer normally emits a single BIOS beep when the computer completes POST but you are not hearing one now it suggests that either the MB or PSU has failed but with the recent trouble that you have had starting the PC up at all it points more toward the PSU.

Just a FYI: If your system normally beeps and the issue was related to other hardware such as the Ram or video you would get certain error beeps when POST fails due to the bad device.

Couple of questions, are you ok with working inside the computer and is your computer the standard tower 545 type or the smaller 545S, the latter is important to know because if the PSU needs to be replaced the PSUs are different sizes/shapes.

A bad CMOS battery is unlikely to prevent a computer from booting (I have not heard of it) and you would normally receive a "checksum error" message on boot and the RTC (real time clock) would display an incorrect time and date.

[phillpower2]

Hello 911pchelp

A bad power supply is the most likely cause of the issue, this includes the PSU itself having failed or a bad connection, one thing that does help point more to a bad PSU is error beeps or the lack of any being heard, if the computer normally emits a single BIOS beep when the computer completes POST but you are not hearing one now it suggests that either the MB or PSU has failed but with the recent trouble that you have had starting the PC up at all it points more toward the PSU.

Just a FYI: If your system normally beeps and the issue was related to other hardware such as the Ram or video you would get certain error beeps when POST fails due to the bad device.

Couple of questions, are you ok with working inside the computer and is your computer the standard tower 545 type or the smaller 545S, the latter is important to know because if the PSU needs to be replaced the PSUs are different sizes/shapes.

A bad CMOS battery is unlikely to prevent a computer from booting (I have not heard of it) and you would normally receive a "checksum error" message on boot and the RTC (real time clock) would display an incorrect time and date.

[911pchelp]

Thanks for the response, PhillPower2 ... fortunately I have a 'little used' laptop to process emails and forum updates.

I don't have a prb working inside computer (assembled custom units a few years ago but used new, working parts ... so not familiar with hardware troubleshooting). Am a previous programmer but not a hardware tech.

It's a standard 545 tower - added a 2nd HDD years ago but no changes in last 12 months.

Was afraid prb might be a bad PSU (just seemed quick ... only 2 days 'notice') - when pwr on prb first appeared and was finally able to boot, had no prbs rest of day.

Can you recommend a good tutorial to determine if it's really a bad PSU? (I have a digital VOM if that helps)

[phillpower2]

You are welcome 911pchelp

Good news that you know your way around the inside of the case as it will save you time and money

Some tutorials for you below;
Demo video
Some diagnostic guidance http://www.aitechsol...chwtrblsht.html
Pinouts http://www.smpspower...rs-pinouts.html

The problem with testing a PSU without the workshop equipment that simulates the computer operating under load is that it is only conclusive if the PSU will not activate at all and so confirms that the PSU is 100% bad.

Do you normally get a single beep when the computer completes POST.
Does the present PSU have an LED on it and if so does it illuminate green when the mains power is turned on at the wall socket, if it does it may point to a bad power button or connection from the front of the case.

Hope this helps.

[911pchelp]

Thanks for the tutorial pointers.

I thought the POST was completed after the BIOS etc done and just before Windows began. Before the problem, the PC would 'single beep' about 2 seconds after the pwr button was pressed (then the RAM was checked - i.e. status bar 'filled').

The present PSU DOES have an green LED - and it IS lit when PC is plugged into wall. That's one reason I was leaning toward a bad switch. I don't suspect a bad connection because the button has an 'interior' light the comes on when the button is pressed and if the button is held down, the light blinks each second - but the HDD light is never activated (nor and fan). I guess maybe that does point to a bad PSU.

I purchased a new Antec PSU from local Walmart (at Walmart.com) last night in case (tho I know a little cheaper other places online but with WM can return the unit if not needed or doesn't fit).

After the holidays I'll concentrate on checking the present PSU and maybe replacing (tho replacement doesn't look too hard so maybe that will be my troubleshooting procedure).

Thanks again.

[phillpower2]

Excuse the title of the tutorial http://www.dummies.c...wer-supply.html

Also please see my canned text below regarding the PSU as it explains a little more of "how" the PSU appears to be working correctly but it is not;

As a PSU puts out various voltages +3.3V, +5V and +12V it may appear that the PSU is working correctly but it is not, any significant drop of any output can prevent the system from booting up, the other scenario is a significant increase in the output which can be worse as it can fry one or more major components such as the MB, CPU, Ram, add on video card etc.
Please be aware that there are no user replaceable parts in a PSU so a bad one should be disposed of in a responsible manner and any type of conclusive testing will need to be done by a suitably trained Tech who has the required testing equipment and the relevant knowledge as to how to use it.

Tip for when you swap the PSU out, before you disconnect any of the cables from the PSU to your hardware, put sticky tabs on them identifying what they connect to.

[911pchelp]

SHEEPISH - EMBARRASSED

The problem wasn't a bad PSU (at least not yet – Maybe in a few months).

I have 2 voltage strips ... the first for hardware necessary for the PC to run (CPU, etc.); the second for accessory hardware (e.g. scanner, wireless headphones, etc.).The second strip had inadvertently been turned off. I turned it on and decided to try powering on the PC – why I don't know. IT WORKED!

Can you think of a reason?

Thanks for all you did phillpower2 ... Sorry for the false alarm.

Bottom line, this problem is resolved.

[phillpower2]

Thanks for the update 911pchelp

We can all overlook the obvious sometimes and by posting this information here you could be saving others with a similar or the same issue a lot of time and headaches.

I hope that the issue is 100% resolved but let us know if you have any further problems.

One thing I would do if both power strips are plugged into the same double wall socket outlet is have the socket checked out in case of a loose wire in the socket itself.

[911pchelp]

The power strips are plugged serially ... 2nd into 1st and 1st into an APC USP. (And CPU plugged into 1st.)

I don't know why the 2nd power strip (and what's plugged into it) would cause power problems at the CPU ... but I won't look a gift horse - etc. It was an easy fix and I know what to make sure of, at the beginning, if something like this happens again.

[phillpower2]

[Adnan.Im]

Thanks for the response, PhillPower2 ... fortunately I have a 'little used' laptop to process emails and forum updates.

I don't have a prb working inside computer (assembled custom units a few years ago but used new, working parts ... so not familiar with hardware troubleshooting). Am a previous programmer but not a hardware tech.

It's a standard 545 tower - added a 2nd HDD years ago but no changes in last 12 months.

Was afraid prb might be a bad PSU (just seemed quick ... only 2 days 'notice') - when pwr on prb first appeared and was finally able to boot, had no prbs rest of day.

Can you recommend a good tutorial to determine if it's really a bad PSU? (I have a digital VOM if that helps)

Hey.. i have the same problem.. can u please tell how can i fix it?
 

[Plastic Nev]

Hi Adnan.Im.

 

Can you pleas start a new thread of your own as your problem may well be a different one, pleas explain every part of it in the new thread you create.

This thread being concluded may become ignored.

 

Nev.