[Electrical] Blown caps

[Tailor]

Hi,
I'm trying to keep an FS-C8525MFP alive.
psu.jpg
The large caps have recently blown, i'm thinking of replacing with these, long shipping though so if anyone has any better options I'd love to hear.2pcs/10pcs 270uf 400v Nichicon GU 30x35mm 400V270uF Snap-in PSU Capacitor | eBay
I also understand that recent firmware updated the sleep routine to further prevent it happening, would someone be able to share?
Thanks all!

Tailor

[KenB]

[allan]

Re: Blown caps

Hi,
I'm trying to keep an FS-C8525MFP alive.
[ATTACH=CONFIG]53859[/ATTACH]
The large caps have recently blown, i'm thinking of replacing with these, long shipping though so if anyone has any better options I'd love to hear.2pcs/10pcs 270uf 400v Nichicon GU 30x35mm 400V270uF Snap-in PSU Capacitor | eBay
I also understand that recent firmware updated the sleep routine to further prevent it happening, would someone be able to share?
Thanks all!

Tailor

Wow those primary bulk tank caps really popped in a big way. You can always go bigger on the capacitance and voltage value that is if they fit in the available space. I have the exact same supply I use for electronic projects. It needs a minimum load to fully switch on.

Those where the days a tech needed a soldering iron.

[KenB]

Re: Blown caps

Wow those primary bulk tank caps really popped in a big way. You can always go bigger on the capacitance and voltage value that is if they fit in the available space. I have the exact same supply I use for electronic projects. It needs a minimum load to fully switch on.



Those where the days a tech needed a soldering iron.

Very true, but that has no bearing on temperature.

[Tailor]

Re: Blown caps

Actually it is pretty warm where it sits, I haven't filtered to temperature and have only found a few so there may not be any but I'll take another look, thanks!

[Tailor]

Re: Blown caps

Wow those primary bulk tank caps really popped in a big way. You can always go bigger on the capacitance and voltage value that is if they fit in the available space. I have the exact same supply I use for electronic projects. It needs a minimum load to fully switch on.



Those where the days a tech needed a soldering iron.

Didn't they! I've seen them dome or even vent a little but these have properly burst open.
Probably 10 years old so can't really blame capacitor plague

[KenB]

[sparkycivic]

Re: Blown caps

If you're going to be working on that power supply, might as well add a 1W 5K bleeder resistor across the caps to ensure that rectified noise spikes cannot built-up indefinitely inside the caps during sleep. I see only certain models have a chain of three SMD resistors populated to drain the caps, while others have the pads but not populated with resistors, and then these ones that have no provision at all for drainage of the bulk storage caps.

Every LVPS should have bleeder resistors across the bulk storage caps! Ive gotten my ass handed to me a couple of times lately by mis-handling the board during removal and forgetting to avoid touching the damn cap traces! It's basic electronic engineering that bleeders be present on caps over 100V! I measured over 300V on some failed boards... in a 120V country!

[darry1322]

Re: Blown caps

If you're going to be working on that power supply, might as well add a 1W 5K bleeder resistor across the caps to ensure that rectified noise spikes cannot built-up indefinitely inside the caps during sleep. I see only certain models have a chain of three SMD resistors populated to drain the caps, while others have the pads but not populated with resistors, and then these ones that have no provision at all for drainage of the bulk storage caps.

Every LVPS should have bleeder resistors across the bulk storage caps! Ive gotten my ass handed to me a couple of times lately by mis-handling the board during removal and forgetting to avoid touching the damn cap traces! It's basic electronic engineering that bleeders be present on caps over 100V! I measured over 300V on some failed boards... in a 120V country!

On some Kyocera machines you can hold down the power button after unplugging the machine to bleed the power supply caps.

[BillyCarpenter]

Re: Blown caps

It's kind of unusual for a capicator to explode like that under normal conditions. I've seen them explode when the equipment was struck by lightning. I'd run some tests to see if anything is shorted to ground before I stuck some new capicators in there.

[sparkycivic]

Re: Blown caps

On some Kyocera machines you can hold down the power button after unplugging the machine to bleed the power supply caps.

I tried that... paid with a burn to my finger and a scream with nurses nearby greatly concerned! They were really nice, so there's that

[Scott]

Re: Blown caps

In 40 years of doing this business I have never seen this...WOW

[copres]

Re: Blown caps

If you have any parts machines at your disposal with similar power supply (does not have to be same brand, could be Ricoh or Sharp} check them as they may be using same size and nominal capacitors in them. I've seen caps pop like that on Ricoh machine after electric company goofed up and connected wrong phase voltage on the ground line and every device with power cord in the office went dark.

[blackcat4866]

Re: Blown caps

I've seen a capacitor fired like a bullet into the rear cover, and denting the metal rear cover on a Canon analog.. And yes, there was that whole series of Canon fax machines, that the capacitors would fail en masse. Into the 8th year, the odds were 50/50 that one of those Canon faxes might actually power back up after powering OFF. I carried three of those capacitor kits ... still have a couple somewhere. Sometimes replacing the capacitors would work, sometimes it didn't.

[KenB]

Re: Blown caps

I've seen a capacitor fired like a bullet into the rear cover, and denting the metal rear cover on a Canon analog.. And yes, there was that whole series of Canon fax machines, that the capacitors would fail en masse. Into the 8th year, the odds were 50/50 that one of those Canon faxes might actually power back up after powering OFF. I carried three of those capacitor kits ... still have a couple somewhere. Sometimes replacing the capacitors would work, sometimes it didn't.

At one point I thought it might be wise to car stock a “ready to go” specimen of said power supply, but then thought better about it.

There were no guarantees that those caps were the problem, and most if not all of those models were without service contracts. It’s better to keep the power supply with the original owner, so as to not introduce someone else’s issues.