Soldering some capacitors

[Gamingphreek]

Well i obtained a laptop recently and it immediately powers off immediately:

Link

That is everything involved.

Now i have neve soldered before. This Laptop is running an ancient PII so wont devestate me if i completely screw up.

Can someone basically tell me what the exact problem is, from what i understand a problem with voltage regulation and ACPI.

Knowing that i have never soldered before yet i still know A LOT about computers (hence the reason i post here ). Since this is no risk can someone sort of gauge how hard this will be and give tips.

I put this in HT because it deals with modding a circuit board something that the other forums dont normally deal with.

-Kevin

 

[damonpip]

The capacitors make up some part of the voltage regulator for the processor. Being so close to the processor, the capacitors were exposed to high heat for a long period of time and no longer hold a charge. Because the capacitors are no longer working, the voltage regulator is providing too much voltage to the processor, which causes it to overheat. It has built in overheating protection, so it shuts itself off.

Fixing the problem will be tricky if you've never soldered before. Surface mount (SMD) components are very small and difficult to solder, and a motherboard is very densly populated, which makes it easy to damage other components. I'm really not sure if it is even possible if you don't have access to a good soldering station.

 

[bobsmith1492]

Go easy on the heat is the main thing. Just dab a small solder blob on the iron tip, then touch the iron tip w/ blob to the contacts and hold it for a second until it smoothes over the contacts. Remove immediately and hold the device still for a few seconds until it cools. Voila!

That's soldering in a nutshell.

If you want better contact but don't care about heat (not recommended in this case) hold the iron on the contacts first for a few seconds then poke it with the solder.

 

[Gamingphreek]

Do i need a special soldering iron for this?

Or will the regular one you can pick up at Home Depot or Lowes work.

-Kevin

 

[PottedMeat]

yeah, a cheapo one will work, as long as the tip is as thin as you can find.

with two pin Surface mount devices however, its easier if you have two cheap pencil irons.
especially when taking components off.

what you should have:
1. a pencil iron ( easier to have two )
2. some desolder wick
3. solder

if you have a fry's nearby you can get pencil irons for ~$5-10

to remove:
warning: ifyou leave the irons on too long, the copper traces will peel off the board.
practice on something you're going to throw away.
1. heat up both irons
2. place the tips on the metal terminals on the surface mount cap
3. apply pressure on the capacitor until the solder melts and you can lift it up
4. use the irons to lift the cap out of the way
5. use some desoldering wick to clean up the site

to add SMT caps:
warning: make sure you observe the polarity on the electrolytic caps
1. melt a small amount of solder on just one of the pads.
2. use tweezers to position the capacitor on the pad
3. remelt the puddle of solder and center the capacitor on the pad
4. solder the other side.

 

[harrkev]

Note: Do NOT use the large "Weller" pistol-grip irons. This is the type that you use to fix a radiator. These are WAY too much for electronics.

 

[Jeffyboy]

Lots of expensive soldering equipment will have different tips depending on what you want to solder. Some heat metal... some provide hot air to melt solder...either way... gotta be careful with plated thru holes n things... make sure you don't pull out the inserts...etc

 

[genghislegacy]

without knowing where is the problem I suggest you not to do anything there. soldering is another issue.