SX280 Bad Capacitors

[Strike4]

My SX280 Motherboards seem to have the same problem. Ill plug in the power supply, big light stays solid orange, then when I press the power switch another small orange light blinks besides the switch and there is a constant low pitch ring. Does this sound like a bad capacitor? 1 of them is bulging SLIGHTLY more than the others on most the boards, it's hardly noticeable. Also where could I get capacitors to these boards and a good guide on how to replace them? How easy is it to replace a capacitor my first time if I never soldered before, am I likely to screw up?

Thanks in advance,
Strike 4

[ratdude747]

Re: SX280 Bad Capacitors

what year of manufacture and brand of cap

some pics would be nice

i bet you have a bad power supply- i had a lot of those do that... open it (it wont kill you since the board received power... which ultimately means that letting it sit for 5 min after shutdown should drain caps). take pics of that.

my guess is the bulged cap is bad news but your current problem is in the psu. find another compatible psu to test with... i had one of those fail without bloating (stupid ost and l-tec)

[PCBONEZ]

Re: SX280 Bad Capacitors

The SX270 and SX280 will both blow about any kind of cap because the don't have enough airflow.

[Strike4]

Re: SX280 Bad Capacitors

Yeah I heard caps are a common problem when it comes to Dells. Ok this is complicated but I have a important question for people that know anything about SX280s or own one. The power supply doesn't plug into the motherboard but rather it's just a cord with a brick that runs directly to the computer there is only 1 plug too, however, because of this there is no 4-pin +12V Connector on the power supply to plug into the board. Now I know you need this, I have tested hundereds of boards and when nothings plugged in this connection I have the same orange blinking light I read it's needed to give power to the Intel Pentium 4 processor or something. So my question now is how do I get power to this connection if there's no cable for it on my power supply? Pictures of the inside of a system focusing on the motherboard would be a great help.

[Strike4]

Re: SX280 Bad Capacitors

Picture of the capacitor bulging the most, is it enough to cause it to dysfunction?

http://i744.photobucket.com/albums/x...uestion001.jpg

Ok the power supply question more clear, the power supply has a cable connecting only to this...

http://i744.photobucket.com/albums/x...uestion003.jpg

But theres no cable on the power supply to connect to this...

http://i744.photobucket.com/albums/x...uestion002.jpg

Could the 4-pin connection not getting power be the cause of my problem? If so is there a different power supply or something I can use to give power to both of these connections?

[ratdude747]

Re: SX280 Bad Capacitors

REPLACE THAT CAP!

that one is clearly failed. very obvious.

[ratdude747]

Re: SX280 Bad Capacitors

that 4 pin is p4 12 power, standard on eveything p4 and newer.
why that would be there makes no sense

[shadow]

Re: SX280 Bad Capacitors

Seems a bit weird to have a 4 pin power connector on a socket 775 motherboard. After a bit of google searching I found that some boards indeed have them.

I thought there was no need for the 4 pin power connector any more due to the new 24 pin ATX connector. However I have seen a board with both a 24 pin ATX connector and a 4 pin connector.

[370forlife]

Re: SX280 Bad Capacitors

My Tpower N750 REQUIRES a 24pin+8pin EPS, thats with a 65W 5000+.

I have never seen any p4/pdc/c2d/c2q/I7 board without a p4/EPS connector.

[ratdude747]

Re: SX280 Bad Capacitors

i have an emacine t5026 with both p4 presscott 775 and both 20+4 and 4 pin p4 connector.

[shadow]

Re: SX280 Bad Capacitors

Well looks like I was wrong.

I thought the P4 connector was made for pretty much only Pentium 4's besides the newish Socket 775.

However it seems to be in use even today.

[PCBONEZ]

Re: SX280 Bad Capacitors

Picture of the capacitor bulging the most, is it enough to cause it to dysfunction?

http://i744.photobucket.com/albums/x...uestion001.jpg

Ok the power supply question more clear, the power supply has a cable connecting only to this...

It's not just heat in your case. [Pardon the pun.]

This photo shows Nichicon HM series and I can see enough of the date code to know they are 2004 vintage.
Nichicon HN and HM made from 2001 thru 2004 had a manufacturing defect.
You should replace all the HMs [And HN if you have those too.]

Edit: I think you do have HN also. The ones with the gold lettering off to the right are probably HN.
.

[PCBONEZ]

Re: SX280 Bad Capacitors

That is a custom made [for Dell] motherboard. - proprietary.
That connector is not used for the normal purpose on that board.
http://support.dell.com/support/edoc.../ug/sysbrd.htm

[Computer-Tech]

Re: SX280 Bad Capacitors

PCBONEZ has it right..
The p-4 looking connector is where Dell connects the hard Drive and CD Rom Drive power leads to..
They have a 4-Pin to SATA/HDD Molex connector adapter...
..
In the Normal P-4 PC World an ATX P-4 Capable Power supply would have a 20-Pin and a 4-Pin power lead for the motherboard.
..
In the SX series of Dell Computers - the motherboard has a DC/DC Converter that supplies the Aux 12VDC power for the P-4. (Incidentally, this was a source of heated discussion in the original P-4 Specifications Industry Working Groups, The P-4 Family had to be compatible with Legacy CPU support, hence the addition of the P-4 Power connector scheme which eliminated backwards and foreward compatibility issues.)\..
Take care gang
Dave Mason
Computer-Tech@phoenixcomputerlabs.com