Hello, Dailing in a Dell demension 4700,Foxconn E210882 Mobo,P4 2.8GHz/1M/800fsb.I noticed two swollen capacitors on the board.They are the plastic film wrapped type w/an X stamped on the aluminum top.There was no leakage but thought after Reinstalling,and setting up this PC,I would replace them.Well it has performed well for a month or two until one day I got blue screen, tried Rebooting and lost the Hal.dll file.After starting again had many different problems until it locked-up with error code "checkpoint(lthr)".after research checked many things,Memory,voltage,CPU temp(it did seem to run somewhat hot @ 48o C)O.E.M copper heat-sink W/shroud and case fan.Ready to start her up again but wondered if those Caps should be replaced,And or if there was some other type of heat-sink for this board.The one I have is straight finned about 2" tall and wide an 3" long.I did see one online that had heat pipes going down to the chip contact plate,waiting for more input before start.Wondering if anyone might have some idea's on this. Thanks
The fact that a capacitor is swollen does not necessarily mean that the capacitor is faulty or the fact that the capacitor is not swollen means that the capacitor is all right. It is more of an indication that the health of the capacitors is not that good. To tell for sure the use of an ESR meter is required to determine the health of the capacitors as a normal capacitance meter may read correctly even though the capacitors ESR is high Unfortunately it is not that easy to remove a capacitor on a motherboard as the negative lead is normally connected to the ground plane and a large amount of heat will be required to de-solder it. Also it is possible to damage internal tracks if care is not taken. When replacing capacitors always use 105 degrees types as normal 85 degrees types will fail after a short time. Fortunately on a motherboard many of the capacitors are in parallel so that one or two going fault do not cause the motherboard to fail, whether it does or not is down to luck.
Have you considered the state of the capacitors in the power supply? These are more likely to give you problems than the ones in your motherboard. Replacement of the power supply may affect a solution to your problem. Unfortunately Dell power supplies for older computers are non standard so you will probably have to get a second-hand one from your local computer repair shop.
I agree,The power suppy is apart,cleaned and will be looked over.I guess that just checking specified volt output on power suppy can't tell ya for sure if good or Bad? ....lucky for me the 2 caps on MoBo are standing alone,But 1 is under the PCI-x and the other next to mem bank 4.clearly see the two leads but tracks are close.Thank you so much for your advice! wish me luck Chow!
Fortunately every board I've replaced caps on went from dead to working fine! Hopefully you will be fine as well.
Good News!! Thanks! because i also have a Ge-Force Video card that has 7 out of the 12 Caps on it split wide open like an X. These don't have the plastic wrap around them like the others if it that matters.But it Produces a picture so after replacment hoping to use it on a build project! Old teacher told me this not cost effective. But sounds green to me.nice to recycle or reuse when not used for Important Systems....aye?
A swollen capacitor is on it's out. pjmelect is incorrect. I bet any amount of money that if you were to remove that capacitor and check it's measured capacitance against it's marked values, it would be out of tolerance by probably a good margin. When an electrolytic capacitor swells, it's due to gassing of the electrolyte. Electrolyte that has been broken down into gas no longer contributes to the capacitance of the capacitor, and causes it's value to drop. Considerably. Feel free to try this sometime.
I have repaired many hundreds if not thousands of motherboards and power supplies. It often amazes me how some caps in such visually bad condition measure correctly on the capacitor/ESR meter where as others that look perfect are faulty. Often capacitors that are swollen are faulty but not always. Anyway when I get a motherboard like this I replace all of the capacitors of the same type that are swollen regardless of the visual condition as unfortunately on a motherboard most capacitors can’t bet measured in circuit because they are connected in parallel with other capacitors.
If you’re interested where I buy the replacement capacitors from, the cheapest source of the components that I have found is eBay. Traders there sell 105 degree types from Hong Kong for very cheap prices and normally they are very reliable and deliver in only two weeks or so.
If anyone here is interested in the analogue ESR meter that I use, it is one I designed and built myself and if you want to have a copy of the circuit then PM me. I am also designing a PIC based ESR/capacitance meter that I will be publishing later on my web site.