A little experiment on MB repair

[Dauntae]

A few years ago I built a system for a friend and about a year ago his MB started giving him fits so I put a new one in out of the few 775 boards we could still find, Any way I held onto the board, A Biostar but forget what model but anyway I was going through my stock of parts and came across the board and took a closer look and seem to have found the issue. One of the caps is bubbles up that go around the CPU and since I LOVE to tinker and do have enough parts to actually build an entire PC Grant it not a great rig but non the less an entire PC I figure I may try to replace the capacitor and see if I can get that thing to run for the fun of it. For parts I have laying around are

4 gigs DDR2 ram
a number of old GPU's
about 4 old towers
4-5 200-320 gig HD's
a few off brand PS
and tons of old cd drives.
A core 2 duo 6400

Now the big question, Where would be a good place to get a replacement cap once I ID what it is? Here is a pic of the puffed up topped cap. Now before any one warns me against NOT doing this LOL All this stuff could go Poof in a cloud of flaming poop and I would not be bothered. Just want to see if my soldering skills are up to this and who knows, Might end up with a beater system or one to donate to some kid without a system. For soldering I have a Weller WES51 soldering station so I can control the heat and use a fine tip also. Looking a little closer it's a 1000uf 6.3V on the other side of it.

Dauntae

 

[carnageX]

Could try looking at a local electronics shop (e.g. RadioShack), and if you can't find the proper capacitor there, DigiKey is a good place for components:
DigiKey

 

[Dauntae]

I've been doing a little digging and this particular one is very common, Have a few towers with old dead MB So may see if I can scavenge parts, I'll be giving it a shot this weekend and either it works or it goes poof lol but either way I'm gonna have some fun with it.

 

[Joe C]

Takes much more skill to de-solder a cap than it does to solder a new one back in. You can go with a higher volts on that cap, like from 6.3 v to 10v but you must never go lower and you must never go with anything other than the original uf (micro-farad) size, in your case that's 1000uf. Radio Shack is you best option but there are differences with quality of caps, Teapo and Capcon have terrible reputations while Rubycon has a very good reputation for making quality caps. Japanese caps are said to be the best. You can also order cap kits (for a total re-cap of the board) from a place called Bad Caps.net

http://www.badcaps.net/

 

[Dauntae]

I've seen that site, good selection, I'm no pro but do a fair bit of soldering, Might just practice on a few old junk boards before I attempt this one, I'll be happy if I succeeded, If it works out I found someone in need of a cheap system but haven't told him about this one yet, I usually take all the old spare parts and put together cheap systems for people who are broke and need a basic system. I do it for free and they just pay for whatever parts I'm missing to do it, My way of giving back instead of just trashing dead systems that people want to replace with a build. If I can do this then I may have a few more systems to hand out.

Dauntae

 

[Dauntae]

Well got a junk MB to practice on so de-soldering, Found the easiest method was to cut the bad one off flush with the MB and pull from the back, For the left over solder I just used a very small drill (I'm a machinist so have access to VERY small drills LOL) in a pin vice. Well pulling the old caps off the junk MB was just not working well so I ordered a 20 pack of Rubycon caps for $7 shipped so just need to wait for them to come in and solder them in and then give the board a test run.

Dauntae

 

[Joe C]

Actually....the best and easiest way to de-solder anything on a board, is to re-solder it first, The old solder gets hard and won't melt like it should. You add new solder to the old solder, try to get it to mix as much as possible and even try to gently bent the pin back to the north/south east/west in order to get the new solder around the pins. The next step is up to you but I personally prefer to use some de-soldering braid to lift out all the solder with that. A nice clean de-solder will have the cap fall out on it's own and you should have two nice clean holes to re-solder the new cap with. Do Not Get the Polarity Reversed, the cap will go 'POP" and your board will be dead

 

[Dauntae]

I'll have to look more into that, Been practicing on a dead board for now, I've noticed the polarity and which way there in, The white stripe I think was the neg side (I don't recall ATM) I'll try the resoldering tonight after work, Going to have to pick up some braid and give that a try, Hopefully I can find it locally, My local radio shack said they could order the caps but decided to just order them myself and got them cheaper and a better brand. this is a fun little project and hopefully it works out well for me.

Thanks for the advice and it's been a great help.

Dauntae

 

[carnageX]

I'll have to look more into that, Been practicing on a dead board for now, I've noticed the polarity and which way there in, The white stripe I think was the neg side (I don't recall ATM) I'll try the resoldering tonight after work, Going to have to pick up some braid and give that a try, Hopefully I can find it locally, My local radio shack said they could order the caps but decided to just order them myself and got them cheaper and a better brand. this is a fun little project and hopefully it works out well for me.

Thanks for the advice and it's been a great help.

Dauntae

Radioshack should have desoldering braid - when I worked for one back when I was in high school, we had it at least.

 

[Dauntae]

Well got the caps today and went to work, The de soldering braid worked well (Thank you for that tip) and looking close there were 3 others that looked like they may be slightly puffed up so changed a total of 4, Ironically they were ALL the same 1000uf 3.6v caps, Maybe they had a bad batch when they put this one together, 3 went in nicely but the 4th is kinda iffy to me, One pin didn't want to solder so not sure how well it has contact but if it doesn't work, No biggie but hoping it does. I have 2 more doner systems coming in tomorrow so I'll have one for my buddy in need if this doesn't work, Will find out tomorrow night, Gotta get up at the crack of dawn for a 6 hr drive so hitting bed so I'll toss this in a case and see if it boots up then. Will attempt to load windows XP on it and see how it runs and if all is good then hand it over to my buddy. If not I gotta see what the 2 systems coming in are. I know there AMD but what generation and chip I don't know. Might keep one for the TV. Been a fun repair and have plenty of extra caps to try on the next board I find like this. Well if there the same caps gone bad any way.

Dauntae