LC Power Ozeanos Metatron 650W - fan not spinning

[Half-Saint]

I'm having a problem with this power supply (LC8650). It appears to be working fine but the fan is not turning which makes the power supply overheat in about 5-10 minutes, depending on load. I suspected that the fan was broken so I tried two other fans but none of them worked. They just twitch a bit and immediately stop.

Voltage on the fan connector is 12.15V (measured at fan connector pins while the fan wasn't connected).

Any ideas what's going on?

Cheers

[ReeceyBurger123]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Is there a fan speed controller board or thermistor ?

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Added a few pictures. I presume that what you're thinking of is that small green upright PCB behind the fan connector.

EDIT: there are two variable resistors (?) right behind the fan connector. Could they have anything to do with the issue?

I'm not the first owner of this PSU. It was sold as defective - was hoping for bad caps but I love a good puzzle

Cheers,
SainT

[ReeceyBurger123]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Ok allright plug the fan in and check if that voltage on the connector that drives the fan drops out.

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Getting the PCB out of the case requires special skills but I'll give it a shot :-)

[domas]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

well the little board is nightmare to access, so you might want to desolder secondary rectifiers and remove heatsink and look at the board

My guess is that little board is responsible for controlling the fan. Does it have a connector for thermistor on the board? could it be that the two connectors are swapped around?

I recently had to remove a daughterboard like this - damn the main board is two sided, and I do posses soldering iron and desoldering pump only. This seems like one sided board though, should be easy. Try to remove main board from the casing first.

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Alright, I managed to measure voltage without taking the PCB out of the case. It only reads 2.2V while the fan is connected. Even got a nice shock while touching one of the big heatsinks. Damn it.

[stj]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

get the board out and trace the tracks on the fan connector.
one is going to end up at ground, one is going to end up at 12v

one of them will be passing through a transistor on the way.
once you find the transistor you can just bypass it.

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

get the board out and trace the tracks on the fan connector.
one is going to end up at ground, one is going to end up at 12v

one of them will be passing through a transistor on the way.
once you find the transistor you can just bypass it.

OK, I'll give that a try and get back to you. Thanks.

[momaka]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Sounds either like a bad solder joint or perhaps open BJT (if this is what they use to drive the fan, that is - and it most cases it is).

You will definitely need the board fully out to troubleshoot it though. Else, you can just wire the fan directly to 7V (red fan wire to 12V rail and black fan wire to 5V rail) and call it a day.

[stj]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

dont say that, the fan is there to move air, not just rotate.
and remember that in many cases it doubles as a general extractor for the rest of the pc.

IT SHOULD BE DRIVEN AT 12V

[momaka]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

IT SHOULD BE DRIVEN AT 12V

That really depends on the fan.
Powerful fans can be driven at a low voltage and they will move plenty of air.
Cheap low-power fans can indeed be driven at 12V without making too much noise.
The last thing you want is some powerful Delta fan running on 12V - yeah it will cool the PSU alright, but your PC will sound like a vacuum cleaner. No thanks.

[stj]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

that's your opinion,
i love delta fans - i love all powerfull fans.
my main pc has 3x 120mm intakes and a 92mm on the psu - it starts like a jet winding it's turbines up!

[ReeceyBurger123]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Could you take photos of the board please ?

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

I will but most probably not before Monday. Thinking that simply hooking the fan up to 12V might do the trick while being the simplest solution. Provided I don't find that transistor :-)

[Half-Saint]

Re: LC Power Ozeanos Metatron 650W - fan not spinning

Well, as it happens the PSU sat on the shelf until now. Since removing the PCB is a nightmare for which I don't really have the time, I decided to try something else. After verifying that the PSU starts without the fan attached, I simply took the fan cable, routed it out of the housing and connected it directly to one of motherboard fan connectors.

Needless to say, this works but I'd rather pull 12V directly from the PSU.