Gridcase 2 - Power supply voltage

[Atomtan]

Sorry if this is a stupid question, I could tell the 2 x RIFA's in the power supply were starting to go and so I swapped them for like for like replacements.

Before I did this, the supply voltage (using the same meter) was around 15.6v. I notice now that it sits somewhere around 14.75v. Is this voltage now too low?

 

[NeXT]

The RIFA's are on the primary side. Replacing them should never alter the secondary output voltage, or any of the voltages at all.
The rest of the PSU however is known to have age-related cap issues. Have you fully serviced it?

 

[shawnerz]

UUmmmm...what's RIFA?

 

[daver2]

They are EMI (Electromagnetic Interference) and RFI (Radio Frequency Interference) suppressor capacitors - affixed (generally) to the mains input terminals of the equipment.

They come in two (2) sorts - X and Y. Don't mix them up.

When they 'go' you generally know about it - big bang, flames, nasty smoke, war, pestilence etc.

See: https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/

Dave

 

[powerlot]

UUmmmm...what's RIFA?

Oh... you have yet to experience the nose-hair singeing stench of a blown filter cap...

Apart from the already explained intended function as filters, RIFA branded safety caps are infamous because after >20 years the plastic casing cracks and moisture ingress makes them go boom.

Here some samples I pulled out of equipment:



The big one is primed for explosion as you can see on the split in half case, the others aren't far behind.

They're also hidden in the IEC power inlet filter cans (Schaffner branded, for example). I fell for it because I was confident I checked everything, but didn't know those filters can also explode.

If anyone has old stocks of these, they can all be thrown out.

 

[Atomtan]

My power supply went to Raj last summer, he's my go to man from Mumbai who learned his electronics the hard way there. I asked him to give it a proper looking over. He then promptly returned to Mumbai for 6 months but for me, his greatness is worth waiting for!

He, and then my power supply came back in January and SUCCESS!!! It appeared to expire around 5 years ago, I felt the power supply was the culprit but would never have found the issue.

Thank you to NeXT for the pointer to a full power supply service which was beyond me.

This allows me to return relocating the 3v battery replacement and getting it all back together properly.