Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Power Supply Mosfet burned out

Status
Not open for further replies.

ItysNotMe

New Member
Hello again! I have a fairly new 460watt power supply that only lasted me about 4 to 5 months! The company seems not to want to do anything about it and they are located in "China ; (surprise, surprise)! And so I have decided to repair it myself! When I opened it up ; it clearly had a burnt out power mosfet!

Now for the problem! This power mosfet seems to be a very rare find except in "China"! I would have to put my name on a long back order waiting list even to obtain it! Here is the part number and the specs:
Rin SVD2N65F PackagE: TO-220F-3L N-channel enhancement mode power MOS field effect transistor 2A, 650V,RDS(on)(typ.)=4.5Ω@VGS=10V
Low gate charge, Low Crss, Fast switching, Improved dv/dt capability.

Now for the closest two that i have found that are obtainable, but they do not match up 100% and so I need someone who knows, to tell me if they think either would work in it's place or if they may have a suggestion for one! First one is:
IRFIBC30G N-Channel MOSFET 600V/2.5A TO-220 , Vdss: 600V , Id: 2.5A Continuous; 10A Pulsed , Ron: 2.2 Ohms max at 1.5A/10V, Operating Temperature: -55C to +150C,
TO-220 Package.

And the second that I have found is:
Single-Gate MOSFET Transistor N-Channel 600V 2.5A TO220 , IRFIBC30GPBF , 600V 2.5A
TO220 package.

Thank you very much for your help in advance!!! I have so much to learn!!!!
 
Okay I have found a datasheet at https://www.electro-tech-online.com/custompdfs/2012/11/svd2n65.pdf , if I do not answer the needed info correctly! So I will try to answer your question as good as I can! Here is what I am seeing from the datasheet:
Gate-Source Voltage Symbol-VGS +/-30 Gate Threshold Voltage Min 2.0 Max 4.0
Input Capacitance- Typ. 320 Max. 380
Output Capacitance- Typ. 30 Max. 45
Reverse Transfer Capacitance VDS=25V, VGS=0V, f=1.0MHz
pF

Again thank you very much in advance concerning my problem!!! Also I have a "Chinese site if you need any further info!
 
Here is the link to the "Chinese site: **broken link removed** , you may have to let your browser translate the info? Thanks again!!!
 
The two FETs you suggested are actually the same - the only difference is one is manufactured using Lead-Free processes (that's the one who's part number ends in PbF).

Comparing the original SVD2N65F with the replacement IRFIBC30G:

Vds: 600v for each (no problem)
Id: Original is 2A, replacement is 2.5A, so fine.
Rds: Original is 4.5R, replacement is 2.2R - lower is better.
Vgs max: Original is 30v, replacement is 20v. Shouldn't be an issue - gate voltages are very rarely higher than 20v.
Gate threshold: Original is 2-4v, replacement 2-4v.
Gate charge: Original 10nC, replacement 31nC. This could be an issue if it's being switched quickly and the driving circuitry can't cope with more charge - it may get hotter.

So for most cases (especially DC), it's a fine drop in replacement. If it's a switch mode power supply which needs to switch quickly you may find this replacement gets hotter - it all depends what the driving circuitry is rated for.
 
Thank you for all of your detailed info! I was wondering if there is a better replacement that you know of , that I would not have to worry about the heat issue? It is a power supply for a computer and the mosfet that I am replacing is worded as an S-RIN SVD2N65F - 2A, 650V, RDS(on)(typ.)= 4.5Ω@VGS=10V
Low gate charge - Low Crss - Fast switching - Improved - dv/dt capability - PackagE: TO-220F-3L (The fast switching has me wondering if that is going to cause an overheating issue as you had made mention)? Or is that something that is only mosfet related and not necessarily power supply needed? Thanks again in advance!!!
 
Check the transformer, last one I looked at the fets went short and vapourised the primary.
Couldnt tell from the text but change both fets if ones gone.
You'd also be sensible rigging up a test lead with a 60 or 100w bulb in the live supply and try a bulb or resistor as a test laod before you try and power the machine with it.
 
Check the transformer, last one I looked at the fets went short and vapourised the primary.
Couldnt tell from the text but change both fets if ones gone.
You'd also be sensible rigging up a test lead with a 60 or 100w bulb in the live supply and try a bulb or resistor as a test laod before you try and power the machine with it.

Yes I agree with you all the way as I have already seen some evidence of a possible bad diode and definitely a burnt capacitor ; plus bad fuse as expected! The power fet that smoked itself was lose and I have to wonder if it was that way from the factory? I believe that it was ; but like anything else that goes bad and shorts out; there are usually other bad components caused by it! I have not proceeded any further yet since I have some fets on order! But that's not really a valid excuse!

I could have already checked out the other components! The truth is that I have too many things going on, all at the same time and so I will probably get around to it this coming week! Thanks for your help! I would like to know if we are allowed to use product names on here? I ask this because it seems to me that many of our electronic things of today, are now being imported in from China and I am seeing some very cheap quality parts (below normal standards) on what once was trusted good named merchandise! Anyone else noticing this?

Anyway thanks a lot for your help and input! I'll let you know next week how it plays out!!!
 
The fet in my example shorted all three pins, the diode was in the gate drive, as per a lot of switchers, the sitch on off times are different.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top