Inspiron 1150 capacitor identification - help!

[tcn]

Hello all,

First off, thanks for the wonderful website and FAQ section. It's made for some interesting reading. Unfortunately, I think my problem falls outside the normal scope a little bit...

On Sunday, my Dell Inspiron 1150 laptop (a little under 4 years old) failed on me. Specifically, it now refuses to run off mains power (everything freezes and crashes), but will run off battery fine. The battery will also charge fine.

I did some careful inspection of the motherboard, and I think I managed to identify the problem. At the base of a capacitor near to the mains input socket, there is a black mess, looking like it has burst and failed. I presume this is part of a voltage regulation circuit.

Furthermore, based on sight, I have managed to track down the same type of capacitor at the website of Rapid Electronics (here). The capacitor in question looks identical to the left-most one in the picture on the site. Based on measurement of the physical dimensions of my bad capacitor, I have established that it is one of the listed ones with size code 1210 (so the last six, ignoring the "special offer" red highlighted one).

Unfortunately, this is where my investigative work has ended. The rating of the six possibles ranges between 1uF and 100uF - quite a large scope for error if I pick the wrong one... There are no markings on the capacitor at all. Because the capacitor is now bust, I can't just measure it through a meter. There is an identical looking, still good capacitor near to the bad one, but who knows if it is rated the same or not... There's not even a guarantee that it is one of those six...

I emailed Dell to ask them (longshot, admittedly), and the response I got back simply said that I should replace the whole board, not just a single capacitor. I've also tried shooting off an email to the actual manufacturer of the board today (Compeq Manufacturing), but I'm not holding out much hope on this.

I just wondered if anybody had any other ideas for identifying the appropriate replacement part, or other suggestions for fixing my situation. I'm obviously not particularly keen on spending £100ish (~$200) on a new motherboard for a four year old laptop...

Many thanks in advance for anything offered... :-)

[stevo1210]

Re: Inspiron 1150 capacitor identification - help!

At the base of a capacitor near to the mains input socket, there is a black mess, looking like it has burst and failed. I presume this is part of a voltage regulation circuit.

Furthermore, based on sight, I have managed to track down the same type of capacitor at the website of Rapid Electronics (here). The capacitor in question looks identical to the left-most one in the picture on the site.

Tha capacitor on the site you specified is an MLCC. A Multilayer ceramic capacitor. I believe they do not fail with a big black mess because they are solid ceramic caps. In fact the chances of them failing are very very slim, but possible. Not much help here but.... I suppose you could have a look into the software side of your laptop for issues?. It sounds to me like a software issue though I'm not very sure whats going on with the AC adaptor.

Thanks.

[arneson]

Re: Inspiron 1150 capacitor identification - help!

I know that board and that cap well.
I have four of them sitting here next to me.
That cap has not failed ever, but the rest of the power management on the dell 1100 and 5100 systems are suspect.
Specificly that fourty pin controller under the power jack section.
I've been getting them off Ebay in hopes the board is working or just needs a new jack installed.
By the way I'm typing this now on an 1150 that had that burnt crust. This one needed a jack and a power pack.

[tcn]

Re: Inspiron 1150 capacitor identification - help!

Thanks for the responses.

Stevo1210: I wondered about what you say (about that type of capacitor not failing in the way that this one seems to have done). However, there are plenty more identical capacitors all over the motherboard, and none of them have black residue at their base. It looks very much like a typical failed electrolytic capacitor. Of course, it's possible that I've not identified the capacitor correctly, but that link I gave is the only type of capacitor I've found that looks like the existing one.

I can definitely rule out any kind of software problems. The computer will not even POST completely when it is mains powered. Furthermore, if I start it off battery and load into the built-in diagnostics program (independent of the OS), diagnostics will run fine, but if I plug it in to the mains it will immediately crash (not just report an error, but actually freeze up with a memory exception fault).

Anyway, without going into further detail, I can say with absolute certainty that it is a hardware problem associated with running off AC power. I've checked the voltage output of the AC adapter and it is very tight to the specified voltage (19.5V), so I don't believe that there's any fault there.

arneson: glad to hear that someone is familiar with the board in question. I'll take a closer look at the controller you specify when I get home (unfortunately I'm away for the week at the moment). However, the capacitor I mentioned definitely looks very suspect, and I would think it is the prime candidate for the failure. Do you have any idea what the rating of the capacitor is? (it's number C680)

[tcn]

Re: Inspiron 1150 capacitor identification - help!

Any other takers?

[arneson]

Re: Inspiron 1150 capacitor identification - help!

Yes, the black is burn.
It's burn from the over stressed power connector and may have heated that surface cap from it's mount.
Clean the mess off and inspect with a powerful lense. Put the power connector in and move it.
You will see where the arking low voltage feed was starting a mini fire.
If you are lucky with the board you've caught it befor the controler self destructed.
If not your back on ebay buying more of them for ten bucks or less.
If you really decide you want that cap I'll send you a whole 1150 lower unit.
I have way to many of them and believe me they are dead.
I also have three working perfectly, so I'm happy.

[arneson]

Re: Inspiron 1150 capacitor identification - help!

Look at the base pins on this item:
http://cgi.ebay.com/FREE-S-H-DC-Jack...QQcmdZViewItem
This is most likely what you need.

[Paul S]

Re: Inspiron 1150 capacitor identification - help!

That connecter was broken on my Dell 1150 laptop. I tripped over the power cord many times! OOPS!

The four little mounting tabs were twisted off. The prices for a replacment were too expensive. I fashioned a paper clip to fit around the metal case, and extend past the area of the missing tabs. I soldered it to the metal case, and then to the board.

It works perfectly!

[tcn]

Re: Inspiron 1150 capacitor identification - help!

Thanks for the info. I'll definitely take a closer look at that connector when I get home (tomorrow).

Thank you so much for the offer of sending a board. I'll be in touch one way or another (probably tomorrow) and we can discuss the details if necessary (though the fact I'm based in the UK might make life more difficult).

Paul S: nice bit of home fixing! I wish I could do something similar, but my connector certainly hasn't come completely away, or it wouldn't be charging the battery...

[tcn]

Re: Inspiron 1150 capacitor identification - help!

Well I did inspect that connector and I can't find anything wrong with it. My father happens to know somebody at Dell who may be able to help, so I'm waiting to see if anything happens there now...