I blew out mosfets on my 4000-watt power inverter pulling to heavy of a load. It appears that I have international rectifier mosfet Irf1405. My question is are all irf 1405 the same? I see some for $16 each and some for less than a dollar. there is a seller on ebay with almost perfect feedback selling at $1 each for the international rectifier brand. I was considering buying 30 from him. am I way over my head? I am hoping that only mosfets are bad. what are the chances of that being the case?

 

No, they are not all the same. Imperfections in the manufacturing process means that device parameters will be distributed over a range of values. Using the language of random variables, each parameter will have a mean or average value, and a standard deviation denoted by the Greek letter sigma. What the manufacturer will represent is that all devices they market will have parameters that are within ±3 standard deviations of the mean. That represents in excess of 99% of all devices. What happens to the rest is not exactly well known. I suspect some of those devices and some counterfeits are what are selling for bargain basement prices.

 

Other branded 1405's should work just fine. You can check datasheets to make sure.
$16 is much too high. You can buy from from official sources like mouser for $2 or less.

 

Mouser, a reliable distributor, sells them for $1.92 single or $1.44 quantity 100.

Where did you get the circuit? If it does not have overload protection, of course it will blow up when overloaded.

 

Welcome to AAC!

I see some for $16 each and some for less than a dollar. there is a seller on ebay with almost perfect feedback selling at $1 each for the international rectifier brand.

As someone new to electronics, you should only buy from reputable distributors. That means no on: eBay, Amazon, AliExpress, etc. My experience is that most selling on those platforms have no clue about what they're selling and it's likely counterfeits or rejects.

Make sure you get the right package. DigiKey has this for less than $3 so you should be able to get genuine parts for less than that:
https://www.digikey.com/en/products/detail/infineon-technologies/IRF1405STRLPBF/856537?utm_adgroup=Semiconductor Modules&utm_source=bing&utm_medium=cpc&utm_campaign=Dynamic Search_EN_RLSA_Cart&utm_term=discrete semiconductor&utm_content=Semiconductor Modules&utm_id=bi_cmp-384476623_adg-1302921504343575_ad-81432677981976_dat-2333232393759496:aud-807649517:loc-190_dev-c_ext-_prd-&msclkid=d7a4aae07fd310727099cc8f777a2ef3

 

Thank you all for your replies I look forward to gaining knowledge from all of you I will reply with images next and hope that you can explain to me what I am looking at and the direction I should go.

 

I am adding pictures today.

 

More photos

 

There are 24 mosfets 12 on each heatsinck.

 

Should I replace all mosfets or only some? Do you suspect that there is more damage other than mosfets?

 

I did a crude test and found 6 bad near the one that is blown

 

Welcome to AAC!
As someone new to electronics, you should only buy from reputable distributors. That means no on: eBay, Amazon, AliExpress, etc. My experience is that most selling on those platforms have no clue about what they're selling and it's likely counterfeits or rejects.

Make sure you get the right package. DigiKey has this for less than $3 so you should be able to get genuine parts for less than that:
https://www.digikey.com/en/products/detail/infineon-technologies/IRF1405STRLPBF/856537?utm_adgroup=Semiconductor Modules&utm_source=bing&utm_medium=cpc&utm_campaign=Dynamic Search_EN_RLSA_Cart&utm_term=discrete semiconductor&utm_content=Semiconductor Modules&utm_id=bi_cmp-384476623_adg-1302921504343575_ad-81432677981976_dat-2333232393759496:aud-807649517:loc-190_dev-c_ext-_prd-&msclkid=d7a4aae07fd310727099cc8f777a2ef3

when you refer to right package would that be TO-262 IRF1405LPbF? does it need to be lead free?

 

when you refer to right package would that be TO-262 IRF1405LPbF?

The package looks like TO-220 to me:

does it need to be lead free?

What country are you in?

 

Should I replace all mosfets or only some?

I'd only replace the ones that were bad.

I did a crude test and found 6 bad near the one that is blown

What was the crude test?

If any tested with a source-drain short, are any of them in parallel?

 

Yes, it does look like TO-220 to me too. I live in USA. I will accurately test the mosfets when I feel better. I seem to have the flu at the moment.