Hi guys,

Can you please help me or give some advice how to test the Fuse T6.3A 250V. When I’ve replaced cpu of my imac and I installed the display, the flex band v-sync touched the power supply on and blew up. Now I need to replace the electronic parts from the power supply.

I’ve started with the fuse T6.3A 250v from the picture, how can I test it with multimeter?
Thanks in advance

 

Hello there welcome to AAC!
Unplug your power supply from the wall socket.
On your multimeter or DMM.
Insert the black test lead into the COM jack.
Insert the red lead into the VΩ jack.
Turn the dial to Continuity Test mode. It will likely share a spot on the dial with one or more functions, usually resistance (Ω).
We make sure the DMM is working properly .
With the test probes separated, the multimeter’s display may show OL and Ω.( No beep) .
With the test probes touching each other you should hear a beep.
Place one test probe on one leg of the fuse and the other test probe on the other leg of the fuse the position of the test probes is arbitrary ,does not matter placing the black test probe or red test probe on any leg of the fuse you want.
The digital multimeter (DMM) beeps if a complete path (continuity) is detected . The fuse is good. If it does not beep the fuse is bad no continuity. replace the fuse. You have a slow blow fuse there, that's what the T (Time) indicates on the fuse (T6.3A) replace it with the exact same one. And you're done!

 

oh, thank you so much for your good explanation. I’ve tested in the same way you told me above and when I’ve tested with Ω 20k, 200k or 200 simple I get OL, when I want to test with Bep on fuses I don’t have any beep.

I think the fuse T6.3 250v needs to be replaced.

one more thing - when I connect the power supply 220 v , my socket home fuse turns of. Maybe other
electronic parts are blew up.

 

A blown fuse will not be the cause of the receptacle fuse blowing.

Since the fuse appears to be directly on the mains input I can't imagine what could be blowing the receptacle fuse off that fuse is, in fact, open.

It would require a short circuit from the hot mains to ground, is there something on the board doing that?

Can you take a good photo of the other side of the board?

 

here are the pictures:

 

Check the resistance between these two pads:

 

Hi,

That two pads are the N and L, are you sure?

 

Hi,

That two pads are the N and L, are you sure?

Yes, not connected to power, what is the resistance between them?

 

the resistance is OL

 

the resistance is OL

Then nothing on that board can be blowing the fuse in your receptacle. Where do the wires from those pads plug in?

Also, your fuse is almost certainly blown and may be the only thing dead if you are lucky.

 

Those two pads are connected to the main cable source power from the pc..

 

Yes, I knew that but what does it look like?

 

what does it look like the main cable that connects the cable N L from the power supply?

 

Where does that connector plug in? What does that look like?

 

here are the connectors for N L from the power supply

 

Hello there the red arrow inspect that section thoroughly I think it may be pinched do not plug in power supply.

 

Check the resistance across the pins of the mating connector.

 

it is not pinched -

 

Follow the instructions @Yaakov suggested make sure it is not plugged into the wall outlet. This is very dangerous portion follow instructions to the letter please!
If you have any questions stop what you're doing and ask.

 

Now I am getting worried are you still with us say something!