pcb repair

Quite possibly it's a through-plated hole. Is there a track on the upper side?

It is possible you've damaged the hole, or the track on the top surface- it's simply a way of continuing the PCB track through the board to the other side. There should at least be a small ring visible to solder to, and the solder should flow through the hole.

It's pretty common for the unskilled to damage a PCB when removing a component.

You'd normally repair the broken track(s) with suitable sized wire. Fusewire is an easy source of this.

A schematic helps. You can then check continuity from the pins on the socket to the next component.

When you say no track, is there evidence of any track? Boards that take wire ended components are often plated through multi layer boards, so no obvious track either side isn't always indicative of a problem. Assuming you have a pad to solder the component to on one side at least, go ahead, solder the socket in. If it does not work then, just bin it. Any damage to a modern multi layer PCB isn't practical to repair, unless of course its a surface track with an obvious path.

AB

Picture

No track, or no pad?

No track may not be a problem. If the board is double sided the track may be on the top (and the hole through plated). If its multilayer, then the track may not be visible from either top or bottom, as it could be sandwiched in one of the inner layers.

Vias can also be tracks that are on inner layers of the board.

If you have damaged the through plating (unlikely), then with a double sided board, you would just add a wire. With a multi layer board you would need a schematic (or a working board and a multimeter) to work out where to wire to.

No, it's that small ring that is missing and that I need to replace with one of these through hole things.

What is a pad?

Its the circle that the pin is soldered to that is missing and that I somehow need to replace.

Thanks, Stephen.

Stephen a écrit :

They are intended to be used during the manufacture of the PCB, not as a repair item. Just use a bit of tinned copped wire to link through the board to the socket, then reinforce the socket to the PCB with some Araldite.

You can't. Solder a bit of fine wire all the way through the hole & hope it works. It might.

NT

Are you competing with Rodney?

The pad is the ring of PCB trace that encircles the pin - i.e. the bit you solder the protruding leg to in the case of a through hole mounting component.

So yes, the "ring" is the pad (for surface mount components, it will just be a single flat exposed area of track rather than a ring since there is no hole).

Are you sure it had ring originally? If so, its possible that you ripped it off the board when desoldering the old component.

If that is the case, then you will need to find another way to make the connection. If the ring connected to a visible track, then its quite easy. Just scrape off the solder resist coating on the track and use a bridge wire to the pin. If there is no track, is there one visible on the other side of the board?

If there is no track visible on either side, and no pad on the top surface that you can solder to, then you may still find that the through hole plating is fine (and by extension the connection to any internal PCB layers is likely ok as well). You can then use a multimeter on a low ohms range to probe from the hole (stick a bit of wire through it - or even just rely on the leg of the jack socket), and find a close point that is connected to it. Then wire to that.

If it's the ground pin/s of the socket that can be wired to nearly any place that's connected to ground. If not you can also look up the usual circuits for the amplifier chip - in many cases you'll connect to one side of a biggish capacitor.

Again, picture.

NT

I'dhave thought a nice little high impedence crystal earpiece with wirs could be used to detect the correct places if the track is broken. Often its physical movement that cracks these tracks. Be careful not to short tracks though. As has been said most small devices use plated through double sided pcbs, but it may well be that the track is only on the top side in this case. I did encounter one some years back where the actual socket was held down by melted plastic pins and the connections on the actual socket were flat for surface mount pcbs. Either way often a bit of careful bodgery can get them working. Brian

That would typically detect 2 possible places, one of which will work, the other of which will fry things if connected to. It's usully possible to tell which is which by following the cap to the IC, and connecting to the non-IC side of the cap. Usually.

NT

Are the pins of the new socket exactly the same as the old one? You say "no track", which sounds as if it's a surface-mount socket, but bought sockets usually have pins which go through holes in the board and soldered on the other side. There may not be visible tracks connected to the holes if it's a multi-layered board with inner tracks. Provided the hole has a visible ring ('pad') round it on top or bottom surface you should be all right if you solder the pin to that.

Actually, under some circumstances you can - as long as there is at least a bit of track left on one side. You can buy hollow pins with a small flange at one end (I can't remember what they are called), which are intended to be put into home etched pcbs, drilled with larger than normal holes) to effectively make them through-hole plated.

Multicore copperset ... probably hens' teeth now.

OK for double sided but no use for multilayered. I assume the OP has the latter, otherwise there wouldn't be an issue to address. No picture has been forthcoming.

NT