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 $20 |
Make your life easier get the loan and all you need.
Great solution - worked well on a Dimension 5150.
For UK users, spares available from RS (but only in packs of 5) or Farnell (min order gbp20), so may be easier/cheaper to simply buy a new PSU (eg gbp12 from scan.co.uk) - just spend a few minutes figuring out all the connectors you need.
You need electrolytic capacitors, and watch the polarity - make sure the replacements are the same way round as the originals.
Thanks a million.
Phil
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Hey you said it would cost 4$, but my low esr cap replacement in an antec server ps cost 25$ oh well atleast it works.
Thanks so much for keeping this up! I battled this problem for over a year...I finally just had to leave the PC on all the time. After an overnight power outage, it was dead for good so I searched for a replacement supply and found this site instead. Less than $5 later, my PC is working again. Wish I had looked into this a year ago.
Jeremy,
Thanks for your article. I got the same problem (computer wont turn on and the power button was blinking amber) few weeks ago. I had to disconnect all the connections and bleed the power down, and then with some iterations the computer would start. I had opened up the PSU and looked for any blown out capacitor, but found none and then put everything back, and the problem remained. And then I saw your article, in which you mentioned that the capacitor might also be slightly leaky and be bad. I opened my PSU again, and lo and behold, the same two capacitors that you described (5600 and 1000 uF) had slight leaks on them. I replaced both of them and now my desktop is functioning normally again.
Thanks for your post.
SL
Make your life easier get the loan and all you need.
Worked perfect thanks for the info ! My now dead for 2 years computer is a good working computer.
I bought three caps for 6 bux and up and going ! I do have a real nice un solder tool that I use on my pinball machines Hakko 470 is the ticket for sure
Set your life more easy get the loan and all you want.
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WTF?
Thank you! you solved my problem!
Your advice saved the day. Only the 1000uf was bulging and replacing it did the trick.
Thank you very much!
Thank you for the excellent repair guide. A Dimension 5150 here at work was having the exact problem described (BALoD). Figuring that the power supply was the logical place to start, I was trying to find a site to buy a replacement when I came across this site. I opened up the power supply and, sure enough, the 1000uf cap was bulging and leaky. I replaced it and all is good.
The problem was exactly as described and the fix was exactly as described. What a great way to save a whole lot of money !
Thanks for the help !
hi, Jeremy:
I followed the instructions on this website, after assembled together and tested with power supply tester, it shows LL on +12V2.
When connected, the PSU fan does not work, and there is beeping(sounds like from motherboard.) and shows no signal.
I don't know how to troubleshoot, could you please give some advice.
Thanks a lot in advance.
Simon
hi, Jeremy:
I followed the instructions on this website, after assembled together and tested with power supply tester, it shows LL on +12V2.
When connected, the PSU fan does not work, and there is beeping(sounds like from motherboard.) and shows no signal.
I don't know how to troubleshoot, could you please give some advice.
Thanks a lot in advance.
Simon
Simon,
I am not expert on this. But when I replaced my bad capacitors, I also got low +12 V. In my case, I found that while enclosing the PSU case, I had accidentally pinched on a wire, cutting it and shorting it. You can check if nothing of that sort happened in your case. Also, you can check if your fan pins (on the board of the PSU circuit) are actually getting voltages.
SL
After pulling the PS case apart, I found C101 (1000uf 10V) with a bulging top. The other cap looks fine though. I'll replace it for insurance. Also my internal fuse blew, so check yours. It should be clear.
Will get new parts installed and see if it lights!
Thanks
I really appreciate both keeping this info online AND the feedback from folks that worked on this problem. My power light was blinking amber and sounding like a circuit breaker was cycling every 2 seconds following an emergency power shutdown at the sub-panel in our office.
I had a USB contact bent back against the case and I changed the MB battery too, just for the heck of it. Computer came right up. Saved me from massive depression following a string of bad day events.
Thanks loads!
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!
Any capacitor you get from Radio Shack is NOT A REPLACEMENT for anything in a PC PSU!!!!
Radio Shack sells cheap regular grade capacitors, fine for any power supply that runs off 60HZ, but NOT for a switching regulator used on a PC power supply!
The Radio Shack replacement will probably work for a little while, but due to the high Internal Series Resistance and low ripple current rating it will quickly deteriorate and you'll soon be in the same situation, if not worse. This is essentially the reason why the original capacitors failed. They started off with sufficient specs, but due to defective electrolyte, the ESR and ripple current specs dropped below the requirements of the circuit they were installed in, causing the internal temp. of the capacitor to reach a level that caused the venting to fail. This allowed the capacitor to dry out, and essentially become an open circuit.
Use only LOW ESR and HIGH riple current capacitors, if you don't know the ratings of the capacitor you are going to use as a replacement, THEN DON'T USE IT!!!!!!
The following series are all specifically designed to be used in high ripple current applications where low ESR is required:
Nichicon : PM , PW , HE , HD , HV , HM , HN , HZ
http://www.nichicon.co.jp
United Chemicon : LXZ , KY , KZE , KZH , KZJ
http://www.chemi-con.com/
Rubycon : YXG , YXH , ZT , ZL , ZLH , ZLG , MBZ , MCZ
http://www.rubycon.com/
Sanyo : WX , WG
http://www.sanyo.com/components/
Panasonic : FC , FM
FM is sometimes cheaper than FC and better. Both are great though.
Most of the above are available from Digikey and/or Mouser.
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.
Any capacitor you get from Radio Shack is NOT A REPLACEMENT for anything in a PC PSU!!!!
Radio Shack sells cheap regular grade capacitors, fine for any power supply that runs off 60HZ, but NOT for a switching regulator used on a PC power supply!
The Radio Shack replacement will probably work for a little while, but due to the high Internal Series Resistance and low ripple current rating it will quickly deteriorate and you'll soon be in the same situation, if not worse. This is essentially the reason why the original capacitors failed. They started off with sufficient specs, but due to defective electrolyte, the ESR and ripple current specs dropped below the requirements of the circuit they were installed in, causing the internal temp. of the capacitor to reach a level that caused the venting to fail. This allowed the capacitor to dry out, and essentially become an open circuit.
Use only LOW ESR and HIGH riple current capacitors, if you don't know the ratings of the capacitor you are going to use as a replacement, THEN DON'T USE IT!!!!!!
The following series are all specifically designed to be used in high ripple current applications where low ESR is required:
Nichicon : PM , PW , HE , HD , HV , HM , HN , HZ
http://www.nichicon.co.jp
United Chemicon : LXZ , KY , KZE , KZH , KZJ
http://www.chemi-con.com/
Rubycon : YXG , YXH , ZT , ZL , ZLH , ZLG , MBZ , MCZ
http://www.rubycon.com/
Sanyo : WX , WG
http://www.sanyo.com/components/
Panasonic : FC , FM
FM is sometimes cheaper than FC and better. Both are great though.
Most of the above are available from Digikey and/or Mouser.
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