Any way to fix missing solder pad / peeled pcb?

[bascotie]

Are you sure it's not OL you're seeing?

That means there is no connectivity between the probe tips (it literally means "Open Loop"). It can also happen when the resistance is too high for the meter to read.

Sorry Steve, my electrical knowledge is really limited so I'm not sure I understand. I tried upping the meter and measuring again to no avail. I also measured a different point on the motherboard and I just see "1".

 

[(*steve*)]

OK, on an ohms range, with the probes not touching anything, what do you see?

OL
1
01

And if you touch the probe tips together?

 

[bascotie]

OK, on an ohms range, with the probes not touching anything, what do you see?

OL
1
01

And if you touch the probe tips together?

Stays at 1 not touching, and drops to low point something when i touch them together so the multimeter must be workign

 

[dh390]

Yes sounds like the meter is working properly.

Some meters have an Ol & some just have an l. Both indicate an out of range (or Over Load) condition for that setting on the meter.

The circuit you are measureing should have a higher resistance. What it should be we don't know.

The reading you got means the battery won't be instantly drained.

Now what you need to do is try to follow the traces from the battery connection back to the components they connect to (probably an IC & some other parts). You can use your ohm meter to try & verify you have the correct traces & where they go to. Then when you hookup the new socket & battery you can measure the voltage at the parts the traces connect to. This will verify that the battery & socket are properly connected/soldered to the point where the old socket was ripped away from the board.

 

[bascotie]

Yes sounds like the meter is working properly.

Some meters have an Ol & some just have an l. Both indicate an out of range (or Over Load) condition for that setting on the meter.

The circuit you are measureing should have a higher resistance. What it should be we don't know.

The reading you got means the battery won't be instantly drained.

Now what you need to do is try to follow the traces from the battery connection back to the components they connect to (probably an IC & some other parts). You can use your ohm meter to try & verify you have the correct traces & where they go to. Then when you hookup the new socket & battery you can measure the voltage at the parts the traces connect to. This will verify that the battery & socket are properly connected/soldered to the point where the old socket was ripped away from the board.

Thanks. So, for the sake of me understanding this due to me being totally bad at it, what I do is take the positive or negative side of the trace on the board, find where it connects to by following the trace, and use the other pin of my multimeter to check the ohms?

 

[dh390]

Yes. Do that for each trace (you can put the meter on the 200 Ohm scale for this as you should be getting a low near 0 reading). You may also have to look on both sides of the board & do the same there too. You should only need to look at any & all traces that connect to the pads where the socket was originally connected to. You need to make sure that when you put the new socket in that it makes contact to all the points the original did prior to the socket & pads being damaged.


If there is a part that the new socket is not making contact with that the original did you may have to use a jumper wire (if you have access to wire wrap wire you can use that. this is usually like 26 to 30awg) to complete the circuit & make the repair.

 

[bascotie]

Yes. Do that for each trace (you can put the meter on the 200 Ohm scale for this as you should be getting a low near 0 reading). You may also have to look on both sides of the board & do the same there too. You should only need to look at any & all traces that connect to the pads where the socket was originally connected to. You need to make sure that when you put the new socket in that it makes contact to all the points the original did prior to the socket & pads being damaged.


If there is a part that the new socket is not making contact with that the original did you may have to use a jumper wire (if you have access to wire wrap wire you can use that. this is usually like 26 to 30awg) to complete the circuit & make the repair.

Thank you. I'll try it and hope it works this time ><. Still waiting on battery and new socket to come in

 

[dh390]

No problem. Once you get the new socket installed & all seems to be properly connected recheck to make sure there is no short between the + & - terminals prior to putting in the battery.

Keep us posted.

 

[bascotie]

Ok, first test:

Black probe to negative side of where the battery terminal was soldered in, the positive went to (not sure what its called) a tiny block like (resistor?) where the trace ended. I get about .01 when I measure these.

Not sure if I'm supposed to, but if I move the positive to the other side of the (resistor?) it stays at 1.

As for the positive side of the battery terminal, the trace doesn't really seem to go anywhere. I remember it was about a 1/4 inch long line that went to a dot right next to it and that was it.

 

[jpanhalt]

I am decent at soldering to cylindrical batteries, such as AAA sizes. For a coin battery, I would be a bit hesitant as there is not much to dissipate the heat. Is a battery holder completely out of the question? Do you know anyone with a spot welder for battery tabs? (I presume you are not close to Cleveland, OH, USA.)

Since that is a multi-layer board, perhaps you can test whether the damage is more extensive than you think with a temporary power supply or larger battery connected to the leads that have been attached to the board?

John

 

[bascotie]

I picked up a battery holder today. It's a little more difficult since it's not like the original. It has the ground pin coming straight down the bottom instead of off to the side. gonna see if this works..

 

[bascotie]

Alright, so I got the appropriate battery holsters today.

I tried soldering it in and it looked good, but I wasn't getting any voltage from the positive to the negative. I checked the battery, and it looked good, close to 3v. Even with the holster off the board with a battery in it, i could not get it to measure out any voltage when I touched the multimeter leads to the holster +/-

Gave up and dropped it off at a tv repair shop. Waiting to see what happens....

EDIT: I'm 99% which side is negative and which is positive, but is there a way to ascertain that on the board side? It doesn't have any markings.

 

[jpanhalt]

EDIT: I'm 99% which side is negative and which is positive, but is there a way to ascertain that on the board side? It doesn't have any markings.

The positive side of the battery should be marked with a "+."

Did the solder you put on flow and wet the surface,or did it ball up? If it balled up, it is likely you did not have a good solder connection.

John

 

[bascotie]

The positive side of the battery should be marked with a "+."

Did the solder you put on flow and wet the surface,or did it ball up? If it balled up, it is likely you did not have a good solder connection.

John

Looked like it flowed then held a good connection with the board, but even when measuring the battery whilst in the holster using just the holster +/-, I wouldn't get anything unless I put the positive on top of the battery and the - on the negative of the holster.

Sorry, as for the +/- question, I was asking about the positive/negative on the board itself, not the battery

 

[dh390]

That would be a maybe. If the board has polarized caps or maybe diodes on the board that the battery connected to that would be a good indicator. Also you could take your meter on 200 Ohms scale & put one probe on the powersupply / board ground/common/negative trace & then take your other probe & touch it to each of the 2 battery leads. If one gives you a 0 or close to 0 reading that would probably be the NEG of the battery lead. Other than that you could try to look up the specs for the memory IC that the battery connects to to see where the backup battery power connects to & the polarity.

 

[bascotie]

So finally got this fixed. I understand quite a bit more so if the issue comes up in the future, God willing I can do it myself. I realized that the "hole" (which wasn't really a hole, more like a dimple), is where the solder had to touch to get a full connection.

So far working ok!

Thanks for all the help guys