Successful recap of a LCD monitor!

[travbrack]

It's a Hanns G HW173. My boss let me have this failed monitor, thought I'd see if I could fix it. The power light would flash green, and nothing would display. When I tore it apart and found several bulging caps on the PSU and knew what I had to do. Ordered replacement samxon from this site and gave her a try.

In case anyone's interested in my technique, I did it as follows:
1. Add some solder to the pins on the underside of the PCB
2. Heat one side up, carefully begin to work the cap out
3. Heat the other side up, keep working it out. Repeat this until it comes out
4. Use a solder sucker to take the old solder out
5. Put the new cap in, hold it in place with electrical tape
6. Cut the ends, apply solder
7. Clean up brown gunk with denatured alcohol solvent and an old toothbrush

Fired the sucker up and it worked great. First time I've soldered a PCB before too.

[Uranium-235]

Re: Successful recap of a LCD monitor!

Hanns G are terrible. Some Viewsonics are sometimes made with "HaansStar" parts

be sure there is lead in that solder, and some liquid flux in there is good too, but it does make a little more of a mess

[kaniki]

Re: Successful recap of a LCD monitor!

2 things you can try. If you dont want to mess with flux on the board, you can always do a pre-solder on the cap leads and since the solder is now clean on both ends (board and cap) they will solder easily without needing to flux them again so no flux to clean up after the install. but that only works if they both have a good and clean solder layer on both parts.

also, what i like to do is put cut the leads to the proper length before i solder them into place. this way you can cut them outside the board and dont need to worry about scraping the motherboard or circuit board after they are soldered in with the cutters.

[travbrack]

Re: Successful recap of a LCD monitor!

The alcohol did a pretty good job, do you think I'll run into problems if I don't go back and use liquid flux? For solder, I used "high tech silver bearing" from radio shack. No idea if it has lead or not. The monitor works fine now so I'm satisfied as long as it will keep.

[etnietering]

Re: Successful recap of a LCD monitor!

That's the solder I use. It's 62% tin, 36% lead, and 2% silver. Or reverse the tin and lead, I can't remember for sure. Hands down the best solder I've ever used though!

[travbrack]

Re: Successful recap of a LCD monitor!

Yeah, I'm actually a little disappointed that I don't have more broken electronics to fix

[kaniki]

Re: Successful recap of a LCD monitor!

I know the feeling.. sometimes it is fun to just tear things apart and fix them..

In any case, as for the solder, it does not matter if you use leaded or non leaded solder. they will both work. Each person has their own preference, but to say that one will last longer then the other, they are about even.. and if they do break down, it will be long after the equipment is junk anyways..

what i would check is the solder that you use.. some have what they call flux or an acid core.. that basically means that they both have flux built in and you usually do not need to use any extra flux with that solder. all that flux does is clean the oils and stuff away so that the solder will get a good bond. It is usually a good idea to use flux if there is not any built into the solder, but if you just pulled something out, then the areas will usually have a good clean surface with no oil or residue build up and in cases like that, flux is not always a must. best to use your own judgment though.