Corona V2 No Power

[crashxtrme]

Hi,

I need some expert help. I got a virgin corona v2 which is not powering on. While checking the board I found there is no 3.3 v standby.

Another thing I found is the mosfet u5a2 is getting heated up to 75 deg c on standby with power cable connected.

Can anyone please help

I have attached the pic of the u5a2

 

[Martin C]

I'd make that the first component to replace.

 

[crashxtrme]

Hi Martin,

Can you please tell me the component name and where I can buy?

Thanks for your prompt reply.

 

[Martin C]

It's an N series dual channel power MOSFET at 3.3v. I can't find a replacement part without knowing the original specs.

 

[Antalpromille]

Lift the component and measure stby 3v3 on the board against GND, make sure theres no short. If theres a short, find the cause, and if not find and get a replacement component.

 

[crashxtrme]

Thanks Antalpromille. Seems like theres a short in 3.3v line. Will remove the mosfets and check.

 

[crashxtrme]

After removing the mosfet there is a short in the 5v and the 3v line. Any ideas?

 

[Antalpromille]

After removing the mosfet there is a short in the 5v and the 3v line. Any ideas?

Its hard to say, are you sure both lines ar shorted? An usual sollution when designing power blocks is to put 0 Ohm resistors or coils at the output, try to find those and lift them to see what side is shorted.

 

[Martin C]

You're now getting into advanced diagnostics. Prepare to lift a lot of components (MOSFETs more than likely) to find it.

 

[wilzumbi]

friend the first thing to do is remove the mosfet,
depois de remover ele com uma fonte assimetrica injete 3v
see what amperage if = 0
Problem solved replace the mosfet and ready

now is greater than the amperage = 0.10 or 0.20
see another component that heats up

capacitors are often doing the mosfet heats up

 

[crashxtrme]

Thanks for all your support. Can you please tell me the name of the component on U5A1.

Much appereciated.

 

[crashxtrme]

Someone with microscope can help ?

 

[nubleet]

Sorry to revive an old thread, but did you ever find a replacement for this? The lettering on the chip on the board I have is oal 1aj p8ht.