View Full Version : Circuit board crack repair


Chad Hauris
05-03-2004, 08:03 AM
I've got a 90's Magnavox TV in the shop which had got knocked over and the circuitboard is cracked under the flyback (big crack). I know I can electrically repair it with wire but wonder what kind of material (epoxy?) anyone has used to physically repair and stabilize the circuit board..something non-conductive. Have not had to repair this big of a crack before. Since it is going to a client I want to make as firm and lasting of a repair as possible.

Celt
05-03-2004, 09:24 AM
Some here may be able to provide a better solution than I, but how I have always handled this was by first soldering copper joins over the cracked tracings using 18 gauge solid core wire. Then straighten the board and apply a strong two-part epoxy over the cracked area. Give it several hours to set up.

andy
05-03-2004, 10:45 AM
I've always used super glue for this. I like the fact that it has very low viscosity and works its way into tight cracks. I've never had much luck getting epoxy to stick to circuit board material. It looks good, but peels right off.

Chad Hauris
05-03-2004, 11:01 AM
Thanks all for suggestions...still need to see if the customer approves the estimate before going ahead. This set appears less than 5 years old but has had a hard life!

Doug
05-03-2004, 09:41 PM
What chassis is it. I have a few NAP chassis.

Carmine
05-04-2004, 05:43 AM
How about something like JB Weld for the physcial repair?

heathkit tv
05-04-2004, 07:29 AM
JB Weld IS an epoxy....that was discussed earlier in this thread.

Anthony

bolly
05-04-2004, 07:39 AM
Chad, Post a pic of the cct board. Maybe 2, top, and bottom.

Greg

Chad Hauris
05-04-2004, 07:56 AM
JB weld might provide a good physical repair but I was shying away from it because I think it has steel particles in it for strength, which might be conductive.

Carmine
05-04-2004, 11:49 AM
JB Weld IS an epoxy....that was discussed earlier in this thread.

In as much as it must be catalyzed, yes. However because of the sintered metal particles, it bonds to most anything and is very strong.

As to conductivity, I dunno... Can you keep it away from any circuit paths?

heathkit tv
05-04-2004, 12:00 PM
Impractical because of it's messy nature, but am wondering about fiberglass....would this stick to a circuit board? There's a version known as E-glass that I think has a high dielectric.

Anthony

Richard D
05-04-2004, 09:56 PM
I have repaired some circuit boards that looked impossible to fix. align up one edge until it is perfect, then put a drop of cyanoacralate(industrial superglue at hobby stores) then spray it with some "kicker" aromatic ammine also at hobby stores and it forces an instant cure of the glue. then I work my way down the crack to the next area that flexes and repeat the procedure. Once the board is good and soild I rewire it, using small gauge kynar wire where possibe and when done with electronic repair I touch up a few areas with jb-weld and let it sit overnight. The repair is stronger than the original pc board. It is time consuming but for a new or irreplaceable device it's worth it.
Richard.:)
ONE THING I FORGOT If you have ANY cyano glue on your fingers and get some of the "kicker" on them they will instantly bond together and generate heat as it forces the cure that's uncomfortable. Don't ask me how I know this.:rolleyes:

Chad Hauris
05-05-2004, 06:08 AM
Well, I think the customer is going to balk on wanting to pay for the repair so we will probably end up with the set...This thing had holes punched in the cabinet! covered with crayon and marker marks, etc, also kids spilled stuff in it as there is corrosion on the circuitboard, too...it would not have been an easy fix as the customer might have hoped for. I may just fix it for the challenge of it. Thanks again for all your help.