Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Need Help with Board!

Status
Not open for further replies.

dhatab

New Member
So I have this maxent tv that i got for free and needed to fix it. Found a solution on just soldering a capacitor to a part on the board (first image). So i did that and it worked fine until it fell off. I tried to resolder it back on but it came off again with the two silver strips (second image). Is there anyway for someone not well experience with stuff like this to fix it simply or should I take it to a shop? Id rather not pay the money if it isnt to hard to fix. The third pic is a 180 view of the area (back of board)

IMG_1111_med.JPG
IMAG0709.jpg
Untitled.jpg
 

Attachments

  • IMAG0665.jpg
    0 bytes · Views: 0
Last edited:
Hi.

How is the third image related to the first two? Is it oposite side of the board?

If it was up to me I would try using a glue gun, and aplying glue that would do the mechanical, that is to make the cap standing there. The area of the pads on the board is simply too small in order to keep such a big (in height) cap in place.
That will work as long as the temperature near the cap does stay between -40 and 80 degrees celsius (intimated on this wikipedia page).
 
Looks like your capacitor was too heavy for the traces! Try to find a physically smaller one. I'm impressed you got the old one off - knowing how much heat you probably needed to apply, it's probably weakened the traces from the board and they've torn away.

Personally, I would scrape the solder resist off the traces where they've broken off, and solder the replacement cap to there, using the shortest leads you can. You have to scrape very carefully so as not to damage anything - be warned though, it's tough stuff! Then, I would put a blob of glue or something to stop the cap from moving. This is now a tricky repair, so be very, very careful.

Hope this helps :)
 
Throbs has the right idea, except I think I'd put the cap upside down on the board and run 2 short wires to the traces and solder them on.
 
Im not very good at this kind of stuff so I not really clear on everything. I understand that if i scrape on the trace I can solder to the negative side. But Im not sure of where the trace is on the positive side. If someone could just circle where I could scrape on the trace to solder the cap on would be great.
 
Photo is too blurry to tell properly, but it looks as though it was through plated on the + side. On the photo with the cap in place it looks like the one on the edge of the circle, just near the r/h end of the + sign

Read carefully!
Look for a tiny hole in the board where the trace was torn off, poke something thin through it (like a fine bit of wire, NOT a needle or pin!), and where it comes out on the other side is where you need to solder. If it comes out underneath a component you won't be able to see it and things get more tricky. If it is clear then this actually helps your situation, because you can put the new component lead through it. If your bit of wire won't go through, check it's not gummed up with something before assuming the worst. Holding the board up to a strong light may be of use to you since you MIGHT be able to see some detail through it.

If it does come out underneath a component, your options get pretty limited, since you will have to either find another place to make the connection, or remove the component in question and then re-solder it. A continuity tester is your friend in either event. Let us know how it goes :)
 
Remember, we can't tell for sure without it physically in front of us. It looks like you tore off the pads. The negative of the cap looks like it COULD be the isolated trace meaning the resist could possibly be removed and a small wire soldered there.

The (+) Looks like it's from the tiny hole (which is called a via) nearby. Those holes are plated through, so they are like a cylinder connecting the layers of the PC board together.

PCB's can have up to 40 layers and now even embedded components inside of the board.

They are fragile.

Your ONLY hope is to carefully trace where the pads were. Glue a cap elsewhere and possibly use wire-wrap wire to connect.

Yes, there are PCB trace repair kits that can glue copper traces down with epoxy.

You should have used a surface mount cap and solder paste, not solid solder.

Use info at your own risk.
 
Status
Not open for further replies.

New Articles From Microcontroller Tips

Back
Top