Asus p3v4x:burn out ,check mosfet?

[supersabre]

My friend just gave me a p3v4x that has a burn out component. The component is HIP 6013CB.

I notice that the orginial power supply has couples of bulged capacitors, and it possibly causes both hip6013CB and one of the ram to fail.

The mosfet looks good from the outside and I check all of the (rubycon and sanyo) cap using esr meter and all of them are good.

Question: Before i replace the HIP 6013CB, do i have to check the mosfet?
Anyone know how to check it?

[Topcat]

Re: Asus p3v4x:burn out ,check mosfet?

That IC looks to be the voltage regulator IC. If that's cooked, I guarantee the FET's are also fried as well, and quite possibly the northbridge too. I'd say its time to lay that board to rest. If you do attempt to repair it though, definitely let us know how it comes out!!

TC

[kc8adu]

Re: Asus p3v4x:burn out ,check mosfet?

agreed.
i have fixed worse but its more often than not time to drop it in the hole and kick the dirt over it.

[Newbie2]

Re: Asus p3v4x:burn out ,check mosfet?

That motherboard is an old Slot 1 motherboard. Do what kc8adu said, bury that motherboard in the ground. Thousands of years later, somebody digs it up and it goes to a museum.

[Chris1992]

Re: Asus p3v4x:burn out ,check mosfet?

come on, don't hate on the slot 1 boards. abit BE6 in a school comp has a p2-266. runs Word great and has a radeon 7000.

[Rainbow]

Re: Asus p3v4x:burn out ,check mosfet?

MOSFETs might be OK. I've replaced VRM controller on some boards and the MOSFETs were good on most of them. Easy check is "diode test" available on most multimeters - if MOSFET its bad, it has usually shorted all 3 terminals together.
The VRM controller is usually powered from 12V and it's usually the first thing that goes bad when a spike on the 12V rail appears (and Super I/O is the first one for 5V rail...)
The biggest problem with replacing these chips is to find the replacement part. The only source is an unrepairable board. The bad thing is that there is a lot of different VRM controller chips - so I have at least 4 boards laying here that need a replacement and some dead boards with good VRM chips but not the correct types.
And remember: with slot-to-socket adapter, you can run 1GHz P3 there or even a Tualatin (with some work). Or just a cheap Celeron.

[supersabre]

Re: Asus p3v4x:burn out ,check mosfet?

I have another good hip6013cb from the junk board, so i don't have to worry about the chip.

However, i am not sure how to test the mosfet, do i have to remove the mosfet from the board for testing?

Also, i want to ask Rainbow, is the following the way you test the mosfet using multimeter?

****MOSFET testing*****

If you have a suitable digital multimeter you can use this for testing
MOSFETS. The diode test on some multimeters puts about 3v across the device
under test. This is enough to turn on most MOSFETs - at least partially.

So: connect the meter negative to the MOSFET's source.

Then touch the meter positive on to the gate.

Now move the positive to the drain. You should get a low reading. The
MOSFET's gate capacitance has been charged up by the meter and the device is
turned on.

With the meter positive still connected to the drain, touch a finger between
source and gate. The gate will be discharged through the finger and the
meter resistance should go high, indicating a non-conducting device.

[Rainbow]

Re: Asus p3v4x:burn out ,check mosfet?

That's almost exactly the test I'm using to check the MOSFETs when they're out of circuit (and I haven't read that anywhere, just found that by accident ). But it usually does not work in circuit. If the MOSFETs are visually OK, I don't desolder them, but do just a quick check instead - one lead to GATE and the other one to SOURCE (and then DRAIN) to check if they're not shorted. With shorted MOSFET, you usually get very low reading (zero in many cases) and thus a permanent beep.
If you have the chip, then carefully replace it after checking the MOSFETs. If it goes OK, then the board should work fine, if nothing else was damaged by the PSU.

[gg1978]

Re: Asus p3v4x:burn out ,check mosfet?

And even if you can't fix the board by replacing the VRM controller chip, at least you can unsolder the caps from it. The caps from Asus boards of that era are well worth the time unsoldering them.

[kc8adu]

Re: Asus p3v4x:burn out ,check mosfet?

if the fets are ok give it a try.
expect worse damage but you might get lucky.
i remember fixing a few asus boards in the slot 1 days.
most that got damaged like yours had a psu overshoot.

[larrymoencurly]

Re: Asus p3v4x:burn out ,check mosfet?

That IC looks to be the voltage regulator IC. If that's cooked, I guarantee the FET's are also fried as well,

I had a mobo where some caps bulged and the MOSFET next to them turned from black to purplish brown and had a gate shorted to drain-source. I replaced the MOSFET and caps, but the new MOSFET ran very hot, 100C even with a big heatsink. I later took it to my friend's house to borrow his scope, where I saw that the voltage regulator chip, which showed no physical damage, was turning on the MOSFET only partically.

[davmax]

Re: Asus p3v4x:burn out ,check mosfet?

If changing the chip. Check the MOSFETs with the chip removed. Because the chip is most likely shorted it must be removed. Start with one test lead connected to the metal part of the MOSFET body then check the two terminals. There should be no short circuit, zero ohms.

[davmax]

Re: Asus p3v4x:burn out ,check mosfet?

Checking with the controller chip removed you will also be able to compare the condition of all MOSFETs. This will help pick a faulty one.