Looks like bursting batteries what can be done in PC?

[andrew1]

Hi, I wonder if any of you IT buffs might know what the remedy to this is?

 

I opened the PC - a Dell Optiplex 745 to change the little round battery. I noticed these capacitors (I think) which appear to have leaked.

 

Can anyone tell me if these are replaceable/repairable or is the likely end of my motherboard?

 

Thanks

[Mr.P]

I opened the PC - a Dell Optiplex 745 to change the little round battery. I noticed these capacitors (I think) which appear to have leaked.

 

Can anyone tell me if these are replaceable/repairable or is the likely end of my motherboard?

 

Repairable, yes. But before you go spending money on getting the capacitors replaced, it would be worth contacting Dell and seeing if they will repair under warranty. Even if the computer is outside the warranty period, they may consider repairing for free as the capacitors should not be leaking.

 

If Dell won't entertain a repair, it may well be cheaper to replace the motherboard or finding another base unit of ebay.

[andrew1]

I think the date of this is 2007 so Dell are going to be stretched to feel obliged to do this I think. Plus I have a feeling this was an old NHS sell off machine, I didn't buy it myself - would that matter?

 

I'll give them a go anyway as I have the service tag details. Many thanks, but by your answer I am presuming these are the capacitors..cheers.

 

Andrew1

[JoeyJoeC]

Yes, Capacitors will fail eventually. These are "blown" capacitors.

 

They will have two ratings on the side, the voltage and the uf rating.

 

You can replace these, preferably match them like for like.

 

If you can't find the same brand, look on eBay for Panasonic "Low ESR" capacitors, these will last a long time.

 

The voltage MUST be either the same of higher, the capacitance (uf) must be the same.

 

You can unsolder these from the back of the mainboard, if you dont have a solder sucker, then heat each pad up, and pull it out slightly, repeat until you can remove it. Make sure the replacement capacitor is in the right way around.

 

 

Used to fix monitors that have this exact problem

[postmn]

but since its 6 years old is it really worth it since you could get a mobo bundle quiete cheap these days

[andrew1]

Just tried dell and they gave me short shrift.

 

I think the replacement board might be the answer as I am no electrician for that kind of soldering. The Mobo's as you call them are quite cheap. Even a 2nd hand box is fairly cheap.

 

Can anyone tell me though what I might expect to happen here on in as I use this machine daily and I have no idea what these capacitors do or is likely to happen either to them or to the machine. Is it dangerous?, can they catch fire or what? What might be my next experience other than the whole thing going 'phut'?

 

The machine is still working okay so I don't see any changes - yet!!

 

many thanks to all of you thus far

 

A1

[renegadeimp]

Easy enough to replace, but honestly it isnt worth it.

[numbers666]

They look like rectifiers.

 

The cap, if electrolytic, is almost definitely a filter cap that smooths out the rectified AC line voltage that's then switched and stepped down to yield the various system voltage rails. If so, without that cap, you'd be introducing line harmonics and ripples from rectification into your computer and potentially damage other components (or at least stop them temporarily from working correctly per design) they look like they sit around the north south bridge unless your CPU is not fan cooled.

 

There are bundles on eBay starting at a tenner. Or do you spend a little more and get something current ?

 

If you do replace MB you will most likely need new DDR ram as circa 6 years is probably ddr2. Factor in backing up your data as more than likely a new OS installed will be required.

 

Or get the part number of current off it and Google someone may be breaking and have for a fiver.

 

But back up anyway could go tits up any time.

[JoeyJoeC]

They look like rectifiers.

 

The cap, if electrolytic, is almost definitely a filter cap that smooths out the rectified AC line voltage that's then switched and stepped down to yield the various system voltage rails. If so, without that cap, you'd be introducing line harmonics and ripples from rectification into your computer and potentially damage other components (or at least stop them temporarily from working correctly per design) they look like they sit around the north south bridge unless your CPU is not fan cooled.

 

There are bundles on eBay starting at a tenner. Or do you spend a little more and get something current ?

 

If you do replace MB you will most likely need new DDR ram as circa 6 years is probably ddr2. Factor in backing up your data as more than likely a new OS installed will be required.

 

Or get the part number of current off it and Google someone may be breaking and have for a fiver.

 

But back up anyway could go tits up any time.

 

Ignore this guy. 100% sure these are capacitors. Ive fixed motherboards and monitors with the same issue.

 

If you go down the new MB route, you will be better off with a new pc.

[BazzaS]

Ignore this guy. 100% sure these are capacitors. Ive fixed motherboards and monitors with the same issue.

 

If you go down the new MB route, you will be better off with a new pc.

 

I don't see where the poster say "looks like rectifiers" is wrong.

Whilst the actual (AC -> DC) rectifier itself will be diode(s), it is still entirely correct to consider the filter capacitor as part of the whole "rectifier" assembly.

 

I think telling the OP to ignore him is wrong, as why do you feel his point (may appear to work fine but risks further damage) is incorrect?

[numbers666]

Should I have said it is a rectifying capacitor used to smooth the ouput from the diodes? Sorry. My bad. Nevertheless best case is it keeps working, worse case is a burning smell and new MB. In this case they would have been used to smooth the 5v 12v 3.3v lines. Hopefully dell put some paired redundancy in, many causes of the damage, under specced, over voltage, age, breakdown \ drying of electrolyte.

 

In high end boards, you will often find these referred to as military grade, and metal cased vs. Plastic \ card. I too have replaced these, in cb's and high output audio amps.... A little less fiddly due to size but a bigger kick when you fgorget to discharge