Recap Surface mount capacitor

[supersabre]

I don't have experience in recapping surface mount capacitor.

Is it possible to remove the caps with a radio shack 25w iron without damaging the pad?

Any suggestion for removing the surface mount cap?

[-cp-]

Re: Recap Surface mount capacitor

1. add some more solder to both pads (yes, more!)
2. use tweezers to gently (!) lift the capacitor on one side while heating the pad
3. same procedure on the other pad
4. voila..there it is

you can also use the tweezers holding the capacitor while heating one pad and then quickly start heating the other pad. this way the capacitor will come off (nearly) without any force. use some solder sucking wick to clean the pads before recapping.

[kc8adu]

Re: Recap Surface mount capacitor

i use 2 isotip irons with fine tips.heat both pads till solder melts and lift the cap with the irons.

[eclypse]

Re: Recap Surface mount capacitor

How about putting it back on? Iron fine or just buy a heatgun?

[starfury1]

Re: Recap Surface mount capacitor

two irons as KC8 said is what I use when I have too.

There are tools for this if you got deep to very deep pockets

cheapest (and not that cheap) are the tong type tool which is more or less 2 irons like tweezers.


cheers

[Per Hansson]

Re: Recap Surface mount capacitor

I quite like SMT caps, i you can get something to practice on first

I find it much easier to repair a board with only SMT caps vs through hole; no holes to clean at all

[CudaDave70]

Re: Recap Surface mount capacitor

Hello you mother (board) cappers, Just want to ask this simple question, then I will go away . Are the surface mounted caps suspected to be as much "no good" as the through hole radial electrolylic caps? I replaced a cracked LCD panel on a Dell E176FPf and it has this shakey-snowy look to it like it has some EMI problem .
I replaced all the through hole caps except for these 3 aluminum surface mounted ones that are right near the video output ribbon cable. The interference is not as bad as before I changed all the other caps. I even switched the lcd screen to another one, thinking it may have been defective one, NOPE ,I changed the ribbon cable too,NAADA. It is absolutely awful this way so,makes you sick just looking at it, I gotta try it before I toss it against the wall .

[PCBONEZ]

Re: Recap Surface mount capacitor

Surface mount or radial is only the mounting method.
Both can be electrolytic caps.
Both can be poly caps.
.

[arneson]

Re: Recap Surface mount capacitor

Yes surface mount electrolytics are failing.
I see them going out in eight year old radar scanner domes and massive failures in camcorders.
Both hard to repair.

[CudaDave70]

Re: Recap Surface mount capacitor

I changed them out and it didn't help any ,my guess this LCD screen or screens I tried are not compatible with this Dell .I don't know what else can cause this strange look to the display ,it's now a in the box with the others that don't want revived at least till I can get a LCD panel that is compatible with this E176 FPf. I guess just because the connectors fit together ,don't mean they are compatible with each other.

[kc8adu]

Re: Recap Surface mount capacitor

is the busted lcd too bad to see if the same interference is present?
and pull the ccfl tubes before tossing it.

[CudaDave70]

Re: Recap Surface mount capacitor

Yes it was busted up pretty bad ,It also had a problem with some bad caps and no video when I tried it , that is possibly why it had a big ole fist print in it in the first place . I tried two different screens and it is the same problem on both .
Would a failing transistor produce this kind of interference on the screen? I had one similar to this one ,doing almost exactly the same thing ,I replaced all the capacitors and it was almost gooder than new after that.
The box of junk just keeps growing. I removed the lcd panel from the LCD assembly and kept the lamps the frame -housing ect and tossed the panel after I removed the circuit board to use for spare parts in desperate times.

[CudaDave70]

Re: Recap Surface mount capacitor

Does anybody know what the 4s. marking is on these capacitors ? Does it indicate 6volts (I would assume). This is an LCD Control board out of a 22 inch Sharp TV . It turns on, has sound ,the backlignts are working ,but the screen is all segmented with all kind of weird designs and colors (mostly grey) .The longer it is on ,the brighter it gets. I am thinking of recapping this before I replace the whole board,but I don't know for sure what this 4s. indicates on the top of some of the smd caps.

[kc8adu]

Re: Recap Surface mount capacitor

likely 4 volt

[PCBONEZ]

Re: Recap Surface mount capacitor

I agree.
The "S" looks like a logo.

[CudaDave70]

Re: Recap Surface mount capacitor

Thanks for that,I am going to go with it ,There were also somemore on this board that said 6 s that is why I said 6volts I just took picture of the 4 s ones.There are about 50 caps on this LCD Control board. Would it be better(SMARTER) to replace all the caps or buy a used and working board for around 60.00 dollars?
Dave

[PCBONEZ]

Re: Recap Surface mount capacitor

It depends on what you have more of.
Time or money.

.

[PCBONEZ]

Re: Recap Surface mount capacitor

This depends on if the card fires up (works) at all.

When in doubt and if possible just check volts on cap with a multi-meter by connecting the probes to solder points on the other side of the PCB.
Remember, depending on what the cap does there might be times when volts changes because of what circuit is doing (device mode/condition.) so if you aren't sure of the caps purpose check the volts in all known operating modes to be sure.

[PCBONEZ]

Re: Recap Surface mount capacitor

If you know the purpose of ANY of the caps 'with the same marking' (and so know if the voltage should be changing with mode changes) then check the volts on that one.

- If it's over 4 you know 4v isn't the voltage.
- If it's under 4 the you still only know it might be 4v,, because other caps might be on higher volts.

I'm pretty confident the mark is for 4v though.

Just rambling on about methodology~~~~~~~
.

[CudaDave70]

Re: Recap Surface mount capacitor

I also tend to ramble,but it is almost always because I don't know about something ,your ramblings are valuable information and greatly appreciated by me and I'm sure many others that are reading it. I absolutely have more time than money
plus it isn't much satisfaction just replacing boards,Where's the challange ? I never got burnt doing that.
Thanks man