Is This a Blown Cap?

[matt.lacey]

I figured it'd look more corrosive than this, and I had a Saturn before that had some gunk securing caps in place which looked similar, but I'm aware that there's clear glue here too. Tried to fire up my STE for the first time in a couple of years and getting 2 bombs quickly followed by 4. Reboots appear to be four at once. It's got 4MB of RAM so I tried all combinations of 2MB but no dice.

Didn't look at the PSU at first and that stuff was facing away from me.

PXL_20230225_214508506.jpg

[matt.lacey]

Realised after posting - and while waiting for approval, that more of said gunk is around a few other components such as the inductors, so I'm guessing it's 99% not capacitor viscera.

[stephen_usher]

The beige stuff is to stop the components being shaken off the board during transport.

[rubber_jonnie]

As others have said, it isn't capacitor goo, rather a glue type substance used to retain the larger capacitors.

Typically goo is liquid and it is around the base where the rubber bungs and leads are, and it is sticky and smells like rotting fish. It usually leaks out because the bungs dry out and don't form a good seal anymore.

The other failure mode is when the cap 'blows its top'. This is usually when there is an internal failure and the liquid inside boils, but the bung still has a good seal, so the capacitor bulges at the top and the creases split to release the pressure.

[matt.lacey]

Yeah I've always looked for bulging tops, never seen a description as to why each end would fail before though, that's very helpful, thank you!

[rubber_jonnie]

Yeah I've always looked for bulging tops, never seen a description as to why each end would fail before though, that's very helpful, thank you!

Glad it helped :)