Is this the right capacitor?

[ASHOT3359]

A little background: I'm learning to solder to fix my old graphics cards for fun. Two weeks ago, I didn’t know how watts differ from volts and what a short circuit is. So just in case explain everything to me like I'm 5 years old.

In the photo, all capacitors in a row should be the same (Black ones, 16v and 270 something). I changed one of them because it looked a little "puffy" on the top. I checked the old one with a multimeter, it seems to behave the same way as the new white ones. Did I buy the right one? Or is it better to insert the original back.

p.s. Went through hell to get him out, using ways that make me think i burned and tore everything inside. Oh well. After that I have to change 1-2 mosfet drivers.

[mengfei]

looks ok to me But unless you have the right tool & equipment to repair a 6 layer or even a 12 layer board you won't get that far w/o  breaking other parts more so the PCB trace & pads.

....so did work?

[ArdWar]

It should be fine. Bulk caps usually don't need exacting parameters anyway.

After that I have to change 1-2 mosfet drivers.

Now I'm concerned I assume you at least got hot air/rework station.

[ASHOT3359]

Not yet, the main problem is one (probably 2) of the mosfets (i hope, so i don't need to keep searching) Checked them with bench supply and multimeter set to millivolts. One is not good, the other is worse. Then i plug it in my test rig the card comes to life for a moment and that exact (worse) mosfet driver is lighting up in my thermocamera.

equipment...well. I guess i don't have a pre heater, and this usb microscope is not enough. Should i invest in the preheater? Any recommendations?

[ASHOT3359]

Yeah i got HotAirGun. Used it to desolder capacitor in question. That, and 2 rusty sewing pins. Hope i didn't destroy anything then i was forcing them out with pliers

[807]

...all capacitors in a row should be the same (Black ones, 16v and 270 something). I changed one of them because it looked a little "puffy" on the top. I checked the old one with a multimeter, it seems to behave the same way as the new white ones. Did I buy the right one? Or is it better to insert the original back...

What range did you have your meter on to check the capacitors?

You need to measure capacitance & ESR.

Can you post a photo of the puffy capacitor?

[ASHOT3359]

What range did you have your meter on to check the capacitors? You need to measure capacitance & ESR.

It is a auto range multimeter. Switched to the symbol -||- it shows around 250uf. All of the new ones show 280-290. Close enough? Don't have a tool to check ESR but i ordered it, should arrive tomorrow. What considered bad ESR?

Can you post a photo of the puffy capacitor?

It's hard to see the "swelling" on the photo, so i'll show it on a video. You can see how the capacitor i'm holding slightly warps the reflections while the one on the board does not.
https://drive.google.com/file/d/1-R17Z19uUl6xWu19L6f9uEltM8luS4JQ/view?usp=sharing

[wraper]

This is an aluminum polymer capacitor, no liquid electrolyte to dry out. If it was a normal electrolytic, you would see a vent pattern on top. And this is not swelling, just manufactured not perfectly flat. 250uF is well within spec which usually is +/-20%.

[ASHOT3359]

I have to put it back now ... shit. Tnx you all.

Oh btw, can somebody tell me a good way to isolate capacitors from hot air?

[Vovk_Z]

a good way to isolate capacitors from hot air?

SMD ceramics? Typically it can withstand some amount of hot time.