Dell SX270 blown and SX280 bulging - first post

[satoshen]

First post here, but I did read the FAQ and didn't find anything specifically addressing a few of the issues I am having.

I've managed to salvage a few older machines from work that were going to be discarded and have isolated the issue to be related to the blown caps and of course landed in this forum.

I'm hoping to get one of the machines up for my wife to use, but am at a loss where to go from here. I've priced the boards on ebay and considered buying one since they're in the $50-$70 range (some advertised with new caps)

I'd much rather do this on the cheap though and I see the cap kits on the website advertised (which I assume replace all caps on the board?) My question is this: Is it best to replace all caps on a board or just the ones that look bad first and then try booting from there. If some caps on a board fail, does that typically mean that the same type of cap on that board will also probably fail?

The first machine is a SX280 (small form factor, yippee). It was running fine but then died to a flashing orange power button. Tried all the usual, reassembled, checked all contacts, etc. I stumbled upon a thread referring to C442 (underneath the hard drive chassis) being a 'suspect' cap and sure enough, mine is bulging. If I could fix the board by just replacing a single cap, this would of course be preferred.

The second machine is a SX270. Just popped it open this morning and sure enough, 2 of the caps (rubycons, interestingly enough) are corroded on top and its clear one was venting from a small hole in the corrosion. The specs on these 2 caps are as follows:

Rubycon MCZ 6.3v 2200uf
Rubycon MCZ 6.3v 1800uf

My inclination (assuming I can find these caps fairly cheaply) would be to replace the C442 on the 280 and the 2 bad ones on the 270 and then retest. For you guys who have fixed the Dell boards, are you recapping the entire board and if so are you experiencing additional failures?

Also, considering these are both SFF machines, how much does heat play in cap failure? Would it be prudent to upgrade my case fan to a higher CFM or maybe cut a custom blowhole or something?

[zandrax]

Re: Dell SX270 blown and SX280 bulging - first post

Welcome satoshen.
It's wise to replace all caps of same brand and model even if only one is bulged: they proved to be unreliable and may fail in a near future, so better recap them all. For same reason, don't recycle old caps from old boards.
Low ESR and high resistance caps deal better with heat: if you want, replace fans with higher flow ones.

Zandrax

[kc8adu]

Re: Dell SX270 blown and SX280 bulging - first post

just buy the kits and do it right the first time.i know the kit topcat sells will be good as he and myself have the experience of fixing many hundreds of these dell boards.you can try to cheap out but you wont get away with it!

[Westie]

Re: Dell SX270 blown and SX280 bulging - first post

Just re-capped my first mb,GX270,I replaced all the Rubycon MH(N) with Panasonic equivelents sourced in Australia(home).The kits would be better as the caps will be the right size and values and save mucking around chasing up parts.

Being down under hinders buying Topcat's kit with postage costs.

[kc8adu]

Re: Dell SX270 blown and SX280 bulging - first post

thats why i suggest folks post their location.
we can better direct them to parts.
these boards are very hard on caps so it is important to get the right ones.

[satoshen]

Re: Dell SX270 blown and SX280 bulging - first post

Thanks for the tips guys, I appreciate it. Okay, I cheaped out on the 280 because the board is not that expensive on ebay vs the kit and just replaced cap 442 since it was the only one showing signs and its a Nichicon. Voila, it worked. Perhaps I will go and recap the other Nichicons at a later date and leave the Rubycons. Its my wife's computer so if it goes down its not going to break the bank.

It would be interesting to see which caps are blowing most frequently on specific boards. Thanks to whomever suggested in another thread that 442 was the culprit.

For the 270, I will probably recap most of the board since I have 2 completely blown rubycons. Desoldering is time consuming but I imagine I could use the practice... and we have some more of these 270 and 280s at work that I'm sure will eventually blow.

[arneson]

Re: Dell SX270 blown and SX280 bulging - first post

This guy is selling a stack of bad sx280's.
http://cgi.ebay.com/DELL-OPTIPLEX-SX...em160292513336
The HD and PS must be purchased if you recap these.

[Topcat]

Re: Dell SX270 blown and SX280 bulging - first post

This guy is selling a stack of bad sx280's.
http://cgi.ebay.com/DELL-OPTIPLEX-SX...em160292513336
The HD and PS must be purchased if you recap these.

If they had the power bricks, those would be a good score for that price. Is that where you got the ones I saw?

[arneson]

Re: Dell SX270 blown and SX280 bulging - first post

Actually, the three I had were from a hotel upgrade
where they knew they had all failed.
I scored them because I saw them mentioned here and liked the form factor.

[jacobnbr1]

Re: Dell SX270 blown and SX280 bulging - first post

Hello again,

I seek some assistance for a sx270 that i recapped.

I am currently using the machine right now to type this so i have had luck on getting it going as it had nothing to start with.

The issue is when the pc powers itself down upon automatic command from a driver or software install the display video feed is lost and will not restore itself.

The only work around is to repower it down by holding the power button and then doing a power up from off.

Maybe a bios problem.... Hmmm.. not sure but i will try and cross the pins to be sure.

I was into another sx280 yesterday that had already had new caps put in and i could tell every cap they installed as there was flux in those areas.
Looks like they replace about four of them and this time differant ones blew so i am going to agree that prolly all of the caps need to be replaced when doing these.

Thanks