# [SOLVED] Dell Dimension C521 will not start up



## sleighedalive

My son's computer was working fine one day, he tried to turn it on the next day and it would turn on.

There is nothing on the monitor at all, the fans constantly run, the light on the power switch is a solid amber and none of the diagnostic lights are illuminated. Also nothing connected to any of the USB's has any power.

I have checked the voltages on the power supply connector and all appear to be OK.

Any idea anyone?


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## Doby

*Re: Dell Dimension C521 will not start up*

If your sure the psu is good its most likely a motherboard gone bad


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## sleighedalive

*Re: Dell Dimension C521 will not start up*

There is a label on the side of the Power Supply that lists the following voltages: +5V
+5V (FP)
+12V
-12V
+3.3V

So with the mains lead connected i switched on the computer and i measured the following voltages on the connecter leading from the Power Supply whilst it was plugged into the Mother Board.

All Red wires measured 5V
The Violet wire measured 5.1V ( which i'm assuming is the 5V (FP) )
The White wires measured +12V
The Blue wires measured -12V
The Orange wires measured 3.3V
There is also a Grey and Green wire on the connector, i'm not sure what they are for but my guess is they are associated with the power on switch.

So yes i am fairly confident that the Power Supply is good is there any checks i can do to confirm its the Mother Board. Would it be possible to repair. Is there a common fault. I have access to common components like Resistors and Capacitors and i am pretty good with a soldering iron. Any advice would be greatly appreciated.


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## Wrench97

*Re: Dell Dimension C521 will not start up*

When when you push the power button do the 4 Diag lights on the back do anything?
You could try a CMOS reset.
http://support.dell.com/support/edocs/systems/dimc521/en/SM_EN/syssetup.htm#wp1062024


Diag lights http://support.dell.com/support/edocs/systems/dimc521/en/SM_EN/tshoot.htm#wp1064555


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## sleighedalive

*Re: Dell Dimension C521 will not start up*

On this machine the diagnostic lights are on the front above the Power On switch and they do nothing at all.

With the power off i linked together both pins on the RTCRST jumper for 5 secs, removed the link and tried to reboot. No change.


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## Wrench97

*Re: Dell Dimension C521 will not start up*

No diagnostic lights and a good power supply is indicative of a bad motherboard, and Dell motherboards are proprietary meaning a standard ATX board won't line up in the case correctly.


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## sleighedalive

*Re: Dell Dimension C521 will not start up*

Whats the chance of it been the processor?

I'm a little bit worried about buying a new motherboard and plugging my existing processor into it. If its the processor that is faulty could it damage my new motherboard.


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## Wrench97

*Re: Dell Dimension C521 will not start up*

It's possible but unlikely to damage the board it usually works the other way around, the motherboard damages the cpu due to overvoltage.


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## sleighedalive

*Re: Dell Dimension C521 will not start up*

Think i might purchase a new mother board. Is there a step by step guide anywhere for replacing a motherboard and getting the pc up and running again.


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## Wrench97

*Re: Dell Dimension C521 will not start up*

Yes > http://techreport.com/articles.x/13671

But be aware with a Dell you need to a Dell board because a standard atx motherboard won't fit properly.


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## sleighedalive

*Re: Dell Dimension C521 will not start up*

Fitted new Motherboard and computer now working ok. Thanks for everyones help.


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## Wrench97

*Re: Dell Dimension C521 will not start up*

Good to hear.


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## Doby

*Re: Dell Dimension C521 will not start up*

Glad your all fixed


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## Bloomington

I am also facing the same problem, I checked the power supply other parts and looks like all are working fine. I am looking for buying the new mother can you please let me know where did you buy your mother board? Thank you.


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## sleighedalive

I bought my mother board from ebay seller dellkid1. It cost me £41 + £12 P+P.


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## Wrench97

There are a couple of different C521 Motherboards the UT266, HY175 and I think a YY821
here is the UT266> http://www.iso-technologies.com/shop/proddetail.php?prod=UT226


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## hlaplante

wrench97 said:


> There are a couple of different C521 Motherboards the UT266, HY175 and I think a YY821
> here is the UT266> http://www.iso-technologies.com/shop/proddetail.php?prod=UT226


can u buy it off that site because its only 89 bucks 

btw sorry its been a year since this has had a post but still i have the same problem and hope to figure this out and y it does it


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## Wrench97

Yes you can but it from them, make sure you have the UT266 board first.


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## hlaplante

wrench97 said:


> Yes you can but it from them, make sure you have the UT266 board first.


damn my is a hy175 do they replace motherboards if u have a warrenty?


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## Wrench97

If it's still under the base warranty or if you have the extended warranty it will be covered.


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## hlaplante

wrench97 said:


> If it's still under the base warranty or if you have the extended warranty it will be covered.


Can you buy a new one or extend what i have? If so where can i get nor how


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## Wrench97

The warranty is from Dell usually unless you bought it from Best Buy or another retailer.


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## hlaplante

Yea i got it off of dell, how much is it and will they replace my pc 4 free?


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## Wrench97

You would have to buy the extended warranty at the time of purchase, they will repair not replace the pc in most cases.

How old is the PC?


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## hlaplante

wrench97 said:


> You would have to buy the extended warranty at the time of purchase, they will repair not replace the pc in most cases.
> 
> How old is the PC?


its expried already but its from 12/2006

Add on: i just saw this forum post on dells forum site about that they switched from a HY175 to a UT226 and everything works on it but the fan runs high and u cant flash BIOS without hang if you want the URL its:

http://en.community.dell.com/forums/t/19258360.aspx


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## Wrench97

Changing to the UT226 will also cause Windows to fail WGA, and you may or may not have to reactivate and make the phone call to MS and plead replacement costs because the HY175 is still available.
The UT is an older board so I suspect there are CPU compatibility issues with Dual Core processors.


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## hlaplante

wrench97 said:


> Changing to the UT226 will also cause Windows to fail WGA, and you may or may not have to reactivate and make the phone call to MS and plead replacement costs because the HY175 is still available.
> The UT is an older board so I suspect there are CPU compatibility issues with Dual Core processors.


Really on the dell parts site it doesnt show the hy175


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## Wrench97

Your not going to like the price> http://www.impactcomputers.com/hy175.html


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## hlaplante

wrench97 said:


> Your not going to like the price> http://www.impactcomputers.com/hy175.html


Lol i seen that place plus a uk place and the cheapest is on supply sale (on ipod touch ill get the URL soon)


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## hlaplante

sorry for double posting but i got the HY175 Motherboard's site its refurbished and its only $188.77 URL Here: http://www.wdpi.com/products/DELL/REF/HY175.html


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## Wrench97

It's not worth it, You could buy a new board and a case, then at least you would have an upgrade path for the future.


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## hlaplante

wrench97 said:


> It's not worth it, You could buy a new board and a case, then at least you would have an upgrade path for the future.


yea i would do that but.. i have a lot of stuff on my hdd and its from the dell company so if i can atless get on the same dell as mine and get all my stuff off of it then i could unless there is a way to make it so you can access your dell's hdd from another pc which doesn't work because i tryed it on my dad's pc? but yea if its easier for me and you just email me at holdenms <at> Gmail (dot) com (helps from spammers =P )


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## Wrench97

Use the hard drive with the new motherboard, they are one of the few standard components.


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## hlaplante

wrench97 said:


> Use the hard drive with the new motherboard, they are one of the few standard components.


alright i'll go with what you said then, i'm starting to build a standard custom built pc just really basic but fast pc


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## Wrench97

What ram is in your current board?
What Video card do you currently have or are you using the integrated?


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## hlaplante

Using intergraded video and i have ddr2 553 1gb ( 2 x 512 mb)


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## Wrench97

This will get you started, I would also change the power supply.
Link	Disc	Price
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128395 GA-MA785G-UD3H	$89.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231087 2x1Gig DDR2 800 $35.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119068 Cent 5 Case	$49.99

$175.97
http://www.newegg.com/Product/Product.aspx?Item=N82E16817703017 = $49.99


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## hlaplante

wrench97 said:


> This will get you started, I would also change the power supply.
> Link	Disc	Price
> http://www.newegg.com/Product/Product.aspx?Item=N82E16813128395 GA-MA785G-UD3H	$89.99
> http://www.newegg.com/Product/Product.aspx?Item=N82E16820231087 2x1Gig DDR2 800 $35.99
> http://www.newegg.com/Product/Product.aspx?Item=N82E16811119068 Cent 5 Case	$49.99
> 
> $175.97
> http://www.newegg.com/Product/Product.aspx?Item=N82E16817703017 = $49.99


this could fit my amd cpu how about the cpu heatsink or do i need to buy one

by the way thanks for the help but i got a cheaper case by coolmaster and getting a thermaltake or what ever they are for the psu but this way is gonna be cheaper than what i had serached


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## Wrench97

The existing heatsink should work.


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