A600 rev.1 capacitors - grrr...

[paul1981]

I have a revision 1 A600 (A300) motherboard in need of re-capping. I think there's four or five caps with signs of leakage, two of them are shown in the attached photo's provided (audio caps).

As you can see, there's hardly any solder/pad area to work with here on this board with regards to the caps. All of the caps have mostly hidden pads. I had another revision 1 board which was exactly the same as this - perhaps all revision 1 boards are like this? Anyway, what's the best approach with removing the capacitors and replacing them when there's no solder area to work on (I presume the pads are mostly under the components!)

The board works fine besides, so I need this sorting and treating quickly before real damage is done. Would tantalum/ceramics be a good idea here so that once replaced they wouldn't need replacing again? Or perhaps small through-hole electrolytic types as they'd be easier to replace. How do you go about removing caps when the solder/pad is mostly hidden so that you can't even get your iron on it...

All advice gratefully received.

[UberFreak]

Some may not like it, but I'm removing this type of capacitors like this:

Use one thin-nose pliers to hold the plastic base of the capacitor in place.
Use another thin-nose pliers to slowly twist (not pull or tilt!) the capacitor, until it detaches.

Holding the base is essential & insures the pads will not be harmed.

And before others jump in to tell you how dangerous this method is, I've done this on over 10 boards with 100% success.

Also, I recommend replacing them with mini through-hole capacitors, they will last longer and will be easier to solder in your case.

[mechy]

I have a revision 1 A600 (A300) motherboard in need of re-capping. I think there's four or five caps with signs of leakage, two of them are shown in the attached photo's provided (audio caps).

As you can see, there's hardly any solder/pad area to work with here on this board with regards to the caps. All of the caps have mostly hidden pads. I had another revision 1 board which was exactly the same as this - perhaps all revision 1 boards are like this? Anyway, what's the best approach with removing the capacitors and replacing them when there's no solder area to work on (I presume the pads are mostly under the components!)

The board works fine besides, so I need this sorting and treating quickly before real damage is done. Would tantalum/ceramics be a good idea here so that once replaced they wouldn't need replacing again? Or perhaps small through-hole electrolytic types as they'd be easier to replace. How do you go about removing caps when the solder/pad is mostly hidden so that you can't even get your iron on it...

All advice gratefully received.

This looks perfectly normal to me on the pad area-the majority of the pad is under the component. you have some serious leakage there especially the audio caps. Clean the area with a acid(vinegar/lemon juice) and then go over with with iso alcohol.
There is no reason why quality electrolytic capacitors wont last another 20+ years, i prefer Panasonic long life caps.
I dont agree with the use of tantalums- especially in power filtering.
I use a fine tipped soldering iron to do these(not a pointed tip, but one with a tiny chisel tip).

[paul1981]

Some may not like it, but I'm removing this type of capacitors like this:

Use one thin-nose pliers to hold the plastic base of the capacitor in place.
Use another thin-nose pliers to slowly twist (not pull or tilt!) the capacitor, until it detaches.

Holding the base is essential & insures the pads will not be harmed.

And before others jump in to tell you how dangerous this method is, I've done this on over 10 boards with 100% success.

Also, I recommend replacing them with mini through-hole capacitors, they will last longer and will be easier to solder in your case.

Sounds good, all of it. Thanks for your advice.

[paul1981]

This looks perfectly normal to me on the pad area-the majority of the pad is under the component. you have some serious leakage there especially the audio caps. Clean the area with a acid(vinegar/lemon juice) and then go over with with iso alcohol.
There is no reason why quality electrolytic capacitors wont last another 20+ years, i prefer Panasonic long life caps.
I dont agree with the use of tantalums- especially in power filtering.
I use a fine tipped soldering iron to do these(not a pointed tip, but one with a tiny chisel tip).

Thanks for your advice. I definitely need a tiny chisel tip - it's next on the shopping list. Cheers.

[amiman99]

I would not twist the caps especially if there is a leakage. The pads are very weak do to corrosion and you WILL pull the pads with the caps. I learned that the hard way when I replaced the caps myself.

[jltursan]

You are not forced to use SMD capacitors :-), given the hard job you're  facing, I would consider using ordinary caps. The motherboard won't be  pretty anymore but it'll be an easy task compared to this.

About  twisting caps, indeed there's a risk to damage pads but usually only  when the leakage and the corrosion are really big. And then you have  very few alternatives, the pads are not thermal conductive anymore and  are really hard to desolder.

[TCMSLP]

Replacing SMD with through hole components is a bad idea.  Not only is it untidy but you risk the components being hit/touched (if not now, at a later date) and the tracks being damaged.

If the job is worth doing, why not do it properly?  If people don't have the skills or equipment there's plenty of people in the community offering to do it at near cost.

[paul1981]

I'll certainly take all of this into consideration. Thank you for all the replies.

On another note, my A1200 died today whilst I was using it. Was having a game on Frontier when the power light went dead! Of course, first thing I did was turn the power switch off on the brick. Fortunately it was just the PSU.

Mechy, do you have any more of those PSU's for sale for a heavily expanded desktop 1200? White if possible! Let me know if you're making a new batch.

This was posted from the aforementioned A1200. :-)