How to fix a Dell CX305N Power Supply
September 25, 2008 by Jeremy Brock
Lately I’ve been seeing a lot of bad Dell CX305N-00 305W power supplies manufactured by Celetronix failing due to leaking capacitors. The story is always the same, “I turned the computer off, now it won’t turn on and the power button is blinking amber”. Normally this is a quick fix but Dell is using BTX power supplies which are costly and hard to find, a replacement from Dell can cost upwards of $90.
To preface, I’m an advocate for replacing bad power supplies however for $2+shipping in parts you can save yourself ~$80. Okay, time to break out the screw driver and soldering iron, as always I’m not responsible for any damage or data loss caused by this project. Test the power supply with a volt meter or power supply tester before putting it back in service.
Before removing the capacitor make note of which side has a dash or solid line, this indicates the negative side. After removing the capacitor locate the uF and volt values on the side of the capacitor, these are used to match the capacitor on DigiKey or Mouser, look for low ESR/impedance capacitors. If necessary sacrifice length to for a smaller diameter. When installing the replacement match up the negative side before soldering, DON’T solder the capacitor in backwards as this will shorten its life span. If you see other capacitors from the same manufacture you may wish to preventatively swap them out even if they don’t look bad.
Tools needed:
- Philips Screw Driver
- Soldering Iron
- Solder Sucker
- Xacto Knife
- Solder
- Multi-Meter or 24 Pin Power Supply Tester
Parts Needed:
- Replacement capacitors, available from digikey or mouser. I use Nichicon's HE Series
- 1000uF 10V - UHE1A102MPD
- 5600uF 6.3V - UHE0J562MHD
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Step 1: Remove the top and bottom screws at the rear (4 total) of the power supply. |
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Step 2: Gently slide the cover off. There is a fan connector which needs to be disconnected towards the end. |
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Step 3: Locate the bad capacitors. Look for either leakage or bulging on the top and bottom seals of the capacitors. |
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Top: 1000uf 10v Capacitor is bulging. Capacitance should read 1.00 Bottom: 5600uf 6.3v Capacitor is leaking Capacitance should read 5.60 Both capacitors aren't holding enough charge |
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Step 4: Remove the bottom four screws and if necessary unscrew the remaining connectors. Use an Xacto knife to cut glue surrounding the faulty capacitor(s). Replace the faulty capacitor(s) and reassemble the power supply. Remember to reconnect the fan. |
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Step 5: Connect the power supply to a wall outlet, if there is no smoke or pops your good. Next short the two pins (green & black wires) in the picture with a paperclip, the power supply should turn on. You can test the 3.3v, 5.0v, and 12v rails with a multi-meter or buy an inexpensive 24pin power supply tester. Testers can be purchased for less than $20 |
I've had the Power supply completely fail on two Dell Dimension 5150 computers and work only intermittently on a third. I spent several weeks trying to purchase a power supply from Dell, but they kept delaying and delaying...
Then I found this webpage. I don't have the skills to replace these capacitors but a local electronics shop did. They repaired the first one (which now works great) and are working on the second.
Thank you, thank you, thank you...
Thank you for posting this repair. I elected to buy a new power supply, found one on line for $39.00. I will repair the old one for a spare. The amber light of death on my Dell E510 came on after 2-1/2 years of service.
I bought a new power supply for my e-510 also,Im keeping the old for a spare. But I cant remember where all the wires go?? P-5 or p-3 ? and p-9 p-8 and p-7?any help you can give?? written or visual??
thanks to this site i managed to repair the bad cap for 56p and now my dell is up and running again
I repaired my power supply for $3.89, both capacitors were bad. If I can steer any business your way I will certainly do it, too bad Dell can't be honest and admit the problem with this power supply. Thanks for your website.
lol yes a Dell..... E510.. Well I just took the battery out and i shut it down like normal, then i unplug it. To turn it back on i just plug it in and the power light flashes for 2 seconds then turns green then goes off for another second , then comes back on works every time but i have E-Set security so if i don't reset the time and date it don't work so good .. I perches this computer for my Mom and well I need it working seeing how I paid Dell just under 800.00 dollars for it :( and if I have to call Dell's help line again well .. We all know how that can be ! and Best buy was no help , it was just by chance I found a link here from Google and after seeing how well the directions are lade out - Thank you for that !- I feel this is something I can do ! But lol I have one Question for you and from seeing you know what you are talking about , can you tell me if these capacitors will work , this is what I was told I should get from others, They are called AVRF Capacitors and Here is a link http://www.alliedelec.com/search/productdetail.aspx?SKU=8621261#tab=Overview I trust this company and they are local to me ! Your help and expertise is Greatly appreciated !!!! Thank you Mr. Brock ! Brian
I stumbled upon this site while searching for a replacement power supply. The instructions were spot on. I now have a working power supply for about $4. Thanks!!!!
It worked perfectly. The only difficulty was locating the capacitor pins on the bottom of the board and overcoming my poor soldering skills.
I looked for a solution to this for over a year. Thanks Jeremy.
I am having a hard time finding which pins are connected to the caps :( Once I figure it out I will take a picture. Has anyone found an easy way to locate the bottom pins? Thanks.
Hello Jeremy,
Thank you so much for this post. It's great to find out that the blinking amber light is not an uncommon problem and that there is an easy fix like this.
It seems like most, if not all, people who tried this method have been successful. However, after going through the exercise and replacing a 1000uf 10V capacitor that was bulging at the top, my computer still would not start. What is different from before is that it doesn't show a blinking amber light, but a solid green light with 1-2-3 number lights on right above the power button. When the power button is pressed, there is 2 consecutive beeping sound and the power seems to come on (the power supply fan is operating and the CPU chip gets warm, but it wouldn't show anything on the screen and does not proceed any further to boot.
Have you encountered this problem before, or are you familiar with this?
Any input would be greatly appreciated. In the mean time, I will do my best to research on this on my own.
Thanks!
At first I found the same 2 blown as shown in step 3. After ordering the replacements from Digi-Key, I saw another one that is blown. In the step 3 photo, it is at the 12 o'clock position above the 5600uf 6.3v Capacitor, and the 3 o'clock position from the 1000uf 10v Capacitor (where they would intersect, betwwen the 2 red arrows). Does anyone know what the replacement description from Digi-Key would be? Sorry, I can solder, but I don't know about electronics. Any help would be appreciated. Thank you.
That capacitor at the 3 o'clock from the 5600uf is a 3300uf 16v.
While replacing the 1000uf & 5600uf, I discovered that the 3 o'clock cap had a leak, but when I removed it I discovered that it was different. Since I don't have a 3300uf 16v cap on hand, I'll have to replace it later. Anyway, I replaced the other two (1000uf & 5600uf) and the power supply came up normal and the PC works. I plan to change the 3300uf as soon as I can get one delivered.
Actually, it should be the capacitor at 12 o'clock from the 5600uf. It is between the heat sinks, just barely visable above the lower heat sink (about an inch or two above it - in Step 3 picture). What is it's value? Thanks.
I have a Dell 5150 and the BALOD. It would work if I reset the CMOS though. Anyway I had a look at the inside of the PUS and there is yellow goo liberally distributed around a lot of the components inside. It's hard to say which cap needs replacing!
Don't worry about the goo. Look at the tops of the capacitors to see which ones are bulging and have a yellowish residue on the top. Those are the ones that you need to replace. On my power supply, they were: 1000uf 10v, 5600uf 6.3v, and 3300uf 16v caps.
Started having the BALOD on my 3 yr. old Dell a couple of weeks ago. Was able to start by repeatly hitting button and unplugging & plugging power cord. Was able to keep it on if I left it on standby. After doing a lot of research on Dell's web site & Wikipedia (See capacitor plauge)found your post on Google. As other posters said it was spot on. Took my PSU apart & found the exact 2 caps that you pointed out bulging & leaking. Wasn't able to get them locally, ordered them from Digikey. They arrived in 2 days. Made the repair for a couple of bucks & it's been working great ever since. Can't thank you enough. You're the best.
after reading your advise, bought the failed capacitor (only the 1000 uF was bulgind), and after putting everything back, it was MAGIC. The computer came ALIVE. Thanks a lot for sharing your knowledge. You have save me money, you have educated me, you have save part of the landfill where the power supply was going to end up, and you help reduced carbon footprint by eliminating another unnecessary power supply purchase.
Thank you, Thank you, Thank you,
Marco
Thanks Guys! BALOD solved with 1.70 spent at the Shack!
Hello Jeremy,
Excellent steps and fabulous idea, most people just throw away damaged PSU!
Is it possible to use another brand of PSU such as HP 340W for a Dell Dimension PC??!!
Regards,
Machine had been running well for 3 weeks after replacing motherboard (power hit.) Now it just flashes amber with no POST. I have tried cpu and power supply swaps(I have another Dell) and same symptom. I have removed every board & memory. I don't think it can be the powersupply, I'm guessing mother board again. Anything else I should try before fighting for a new motherboard? Symptom when I replaced motherboard was no POST and SOLID amber light.
I apologize, usually I read all postings before I post. New battery fixed the problem. Weird.
Jeremy,
I followed your repair tips and fixed my power supply.
The information you provided was spot on.
Thank you.
Jeremy,
Thanks alot for the info on this problem! I went down to Radio Shack and got a 1000uF capacitor for $2.50, replaced the popped one in my PS, and my Dell Dimension is back on the road!
Thanks again.
Is it normal to have white goop on top of the caps and other componets in the PS? The two small blue and purple caps are both glued together with whatever this stuff is. Any ideas how to proceed since I can't tell the condition. I did notice that there are a couple of very pitted soider connections on bottom of the CB.
Hi Jeremy,
Thank you for the excellent post. The caps in your pics look identical to the caps in my PSU. I'm just wondering that whether the +11.2 V is acceptable for the 12 V nominal output? In the literature it says that that the tolerance for this is 5% and therefore the range is 11.4 - 12.6 V. Thank you for your concern.
SLFireBall
Hi Jeremy,
I replaced the 1000 uF cap and my Dell Dimension 5150 is running back. In fact I'm writing this comment using that computer. Thanks a lot for this very valuable advice. Now I'm checking one of my friend's dead Dell. Hope that I can bring it back to life too.
SLFireBall
You made me a hero. A friend's Dell had the exact problem you described. I followed your excellent step by step instructions. Placed the order with Digikey on Sunday. Had the two capacitors on Wednesday. Total cost including postage was $3.81. My friend and I both thank you.
Thanks, Jeremy. I spend just 2 Euro for capacitors and had my PS fixed. But i didn't use exact the same caps as i took out, 'cos i couldn't find them in any shop. BTW I live in Ireland. Anyway I found out that you can change values. For example in my case i had 1000uF 10v and 3300uF 16v and had to replace them 1000uF 16v and 4700uF 16v. But NOTE you can change uF value a small bit up and down, but voltage you can ONLY replace with same voltage or higher voltage, but never with lower. Now my PS work like it should. Thanks a lot again.
Hi Jeremy,
Would you advise me if I can use the old N230P (230W) PSU used in DELL Optiplex GX520I in my Dell Dimension 5150 or I should stick to the 305W PSU and not less or more W ???!
Sorry for keep asking, but I thought you maybe missed my question below your reply to my previous one.
Thanks in advance man.
Hay Jeremy, great work man.
Too bad I messed up; Kaboom on step 5 (too much soldering I guess).
Any way; I have an old DELL Optiplex GX520 with N230P (230W) PSU, do you think it will work for my Dimension 5150??! Or shall I bring a 500W PSU.
What are my options for replacing this PSU by buying another brand, (NOT Dell, cheaper one), what specification should I seek I don’t get this BTX or ATX stuff that was mentions.
Dose any PSU work?
Waiting for your answer Jeremy.
You can get a replacement PSU @:
http://www.newpowersupply.com/product-pr-811.html
Shipping is slow but the price is okay.
Thanks man for the link,
But I’m still wondering if i can use the old N230P (230W) PSU used in DELL Optiplex GX520I in my Dell Dimension 5150 or i should stick to the 305W PSU???!
Thanks man for the link,
But I’m still wondering if i can use the old N230P (230W) PSU used in DELL Optiplex GX520I in my Dell Dimension 5150 or i should stick to the 305W UPS???!
Hi, your steps are well describe. Before removing cover, i tried step 5...why i don't know!!! A low noise like a capacitor deflate came to my ear... i think my power supply it now die!!
I removed cover and i saw small capacitor describe in step 3 leaking, is value :78.9 uf.
Do you think my first step kill my power supply?
I doubt it, step 5 manualy starts the power supply even "if" a fault detected, try replacing the bad capacitor.
Hi Jeremy,
would you please tell me what to do in regards to the comment I posted on Fri, 05/29/2009 - 00:06.
it would be graet if you can help.
Answered
Thank you for the great info. Shame on Dell for not recalling these power supplies.
Thank you very much for your great tips!
I haven't tried to follow your steps yet , but , I have a question before starting.
The "Computer Parts stores" are advising me to replace the PSU and then buy a "UPS" ( as I understood it is a back-up power device that protects the PC from power problems i.e. shortage and excess, and it saves some power for few minutes, long enough to shout down the PC properly in case of Power outage while using the it )
we have some power problems in my area (shortage and outage)
is it true that such power problem is the main cause of the PSU and Capacitance failure and DO I REALY NEED to protect my PC from frequent Power outage (1-2 times a week ) by buying such device (it is pretty costly).
By the way, I have a 10.000 VA Voltage Regulator connected to protect all electric equipments in the house in case of power shortage.
I'm running out of time please please please advise me ASAP!!!
Regards,
Capacitors have a liquid solution inside them, when the solution dries up it turns into a gas and escapes through the vent release on top of the capacitor, this causes bulging / leaking. Capacitors have a rated lifetime (usually around 10K hrs) after which the capacitor "may" fail. If you want to keep the capacitors running as long as possible, make sure the power supply fan is working (to keep the capacitors cool) and unplug the computer when it’s not in use. Over voltage can cause capacitors to fail however the voltage regulator should prevent that, I don’t think a UPS would do much good from a preventative stand point. I generally find it to be a non-issue as this problem presents itself after 1 1/2 – 2 yrs, most people keep their computers for 3yrs, so you’ll likely replace the computer by the time the power supply needs to be replaced again.
Many UPS’s claim to be Voltage Regulators, if the voltage drops below 83V it switches to battery, and if it goes above 135V it switches to battery, this isn’t “real” protection as it doesn’t isolate the line, provide a clean sine wave, or account for small voltage changes. If you’re going to purchase a UPS I’d do it solely as a power backup, not for prevention/protection. Your 10K VA Voltage Regulator should be isolating your electronics and providing a clean 110V.
Jeremy you are a GENIUS, I can’t thank you enough for your assistance!!
Just wanted to post a quick thank-you!! I just followed your excellent and detailed instructions and the Dell Dimension E510 is as good as new!
hi, two small yello caps sitting right beside the two big ones are blowen, do you know the value of them, model n305n, big cap c8 is blowen too..
A few bucks for parts, 30 minutes worth of work, plus your hepful instructions -- and my power supply is fixed!
Thanks for the tips - very helpful, and saved me some bucks!
Regards,
Joe
I ordered a new 305w power supply box for my Dell Dimension E510 computer. I didn't know if I could do the soldering to repair the old oneT. Now I need to know how to put in the new power supply box. Can you help me?
Thanks
Maria
Follow Dell's instructions to replace the Power Supply
http://support.dell.com/support/edocs/systems/dim5150/en/sm/parts1.htm#wp1354645
My daughter's computer had the "power button is blinking amber" symptom and only removing all USB peripheral it booted successfull.
I've follow your procedure and found one bad capacitor (1000uF 10V).
I replaced the capacitor and everything is working properly.
Dell spare parts price in my country are absurds.
Thanks a lot.
Leandro - Brasil
This "warning" pertains to the alternate "400W" PSU which "Dave" reported purchasing in his Jan.2009 comment. IMO the C1011 PSU available from CPUtopia.com is not equivalent or superior to the CX305N-00 unit. Its available power is less, not more than the CX305N's.
Here's a summary of how I deduced that from the respective PSU labels:
I e-mailed CPUtopia asking about the mechanical hooks which hold the CX305N to the tower's side & top surfaces, and learned the C1011 has none, and needs none, SINCE ITS BOX IS MUCH SHORTER!
But, that shorter box means there is something missing from inside the C1011! A portion of the +12Vdc PS is missing! CX305N has +12Vdc_A AND +12Vdc_B, permitting 264W max-total, whereas the single +12Vdc from a C1011 is a 252W max, single section. The missing volume is likely a 2nd L,C filter & wiring.
I would only buy the C1011 for use for emergency B/U, as a light-duty PSU while awaiting repair parts for the CX305N.
I too have benefited from Jeremy's information (Dell Dim.,E-510; same
two e-caps as JB's example), since after replacing those e-caps my PC now
happily boots! Thanks JB!
Found a bad 1000uf 10V cap. Easy to Identify because it was just as the pictures you show describe, bulging top with innards leaking out. Thank you for the no nonsense logical help!
Scott