Capacitor glued to PCB - best way to remove

I need to replace the capacitors on a power supply for a friend. One of the caps have been glued down to the PCB, but how can I remove it without damaging the PCB underneath? It's the large one in my photo.



Also, it's very hard to see if it's 150uF or 750uF. I'm assuming it's rated at 400V as the power supply is switch mode and works with 110 and 230V.

 

Depending on the glue used, I've had a lot of success running boards through 99% Rubbing alcohol, it just eats away at the glue. Give it a little wedge here and there with a flathead screwdriver to break it free and it should pop off.

 

As suggested by Stipo, I'd splash a little Rubbing/Isopropyl alcohol. Methanol/Ethanol is also safe but might leave some residues behind, those can be cleaned with Isopropyl alcohol. Avoid acetone as it can eat away a ton of plastic/polymer stuff.

I'd also try to cut underneath the cap parallel to the board with a thin blade, like an X-Acto, once the alcohol has soaked a little.

Normally, it's not a problem (from an electrical standpoint) if you replace a capacitor by one rated for a higher voltage. The only issue is if it's small enough to fit in place.

 

Judging by component layout and sizes as well as the board size it seems you are going to replace the 150uF reservoir capacitor just after rectification? That capacitor can deliver a lethal zap if not discharged/bled .

Alcohol is the way to go like the others have said. You could also make multiple tiny punctures on the glue/substance's surface, this would allow for the alcohol to break apart the inside of the glue even more without having to fiddle with it a lot.

 

Staying alive in step one is the key to a successful step two...

 

The PSU has been on my bench for about a month, so hopefully that means it’s fully discharged. I appreciate the warning though

I’ll give isopropyl alcohol a try. Thanks

 

To be safe, short the capacitor with a high valued resistor for a few seconds, 100K Ohm or something, ideally a high power one, but if you suspect the cap is discharged, any wattage rating would work as a safety check. If the resistor gets hot/melts, it's not safe to touch the cap and you should discharge it with resistor rated for high wattage.

 

It’ll have a discharge resistor across it anyway...

 

I got it off and I'm still alive. Thanks for the help