Mosfet identification - Original or Counterfeit  - Page 1
Forum section: electronics / beginners

author: nick#18
author_rank: Newbie
timestamp: May 06, 2020, 08:47:03 am
content: Hello eevblog forums! I need your help since i do electronics as a hoddy and i am not that much experienced.I have a 2000w power inverter that use IRF3205 x24 to make power. I had a lightning strike just some meters away from my appliance and i had some of them fried almost completely by the earth wire. The inverter operates normally for some light loads but when i need some more power fault indication light is on.I ordered 8 of them from a local store which is not an official distributor of Infineon in order to replace the bad ones but while i was waiting for my order to come i decided to remove all the mosfets from the pcb to take a measurement by multimeter on them to check if all the others act the same.Finally i had completely different readings from all of them and i proceed to a second order of 16 more mosfets from the same shop.When i collected both of the orders i found out that something is going wrong. The first 8 mosfets seems to be ok and original but the other 16 look poor and not even the irf logo seems to be ok.Could someone tell me by the photos what is wrong with them?Left: 1st order 8pcs that seems to be the same with the fried mosfetsRight: Second complementary order of 16 mosfetsImages could be found here:https://imgur.com/a/oJb6YkF

author: exe
author_rank: Unknown
timestamp: May 06, 2020, 10:28:54 am
content: The one with shiny leads looks dodgy to me, this is not how the come from the factory. On the pic where there are two devices side by side it looks like leads were replaced. I wouldn't trust this shop anymore. I'd ask for replacement, or simply return that parts.My advice is, if unsure, just buy it from one of big distributors. In my opinion it's not worth time- and risk-wise. There is always doubts if you got the originals parts or not, not to say we don't know how the parts were handled, they are esd-sensitive.As of different readings, what and how did you measure?

author: wraper
author_rank: Unknown
timestamp: May 06, 2020, 10:52:52 am
content: If you compare with datasheet, part on the right side is correct.http://www.irf.com/product-info/datasheets/data/irf3205.pdfBoth types of logo were used on genuine IR parts. Also I have 100% genuine IRL8113 from authorized distributor which looks exactly the same. IMHO they simply came from different factories.

author: nick#18
author_rank: Newbie
timestamp: May 06, 2020, 03:07:49 pm
content: Quote from: exe on May 06, 2020, 10:28:54 amThis shop is a big electronics supplier here in Athens, Greece with the biggest catalogue available and i was never dissapointed on other purchases i had in the past. If i had all the same mosfets received i may never check if they are original or not but just thinking that is only an other batch from the factory. Now on, make sure that my next buy will be from a genuine official distributor of the parts i need.Are there refurbished-used mosfets that they put on new pins?I tried measure the diode drop based on these instructions here -->http://electronicsbeliever.com/how-to-know-if-mosfet-is-defective/From the old mosfets i got about 1300-2000 readings on the multimeter on the diode/continuity mode. At some of them i had just infinity.. it was just counting..The new mosfets are all about 625-630 on both originals and "counterfeit"

author: nick#18
author_rank: Newbie
timestamp: May 06, 2020, 03:11:44 pm
content: Quote from: wraper on May 06, 2020, 10:52:52 amGood to hear that you had some that look like the same. About the datasheet, the shop send me exactly the same you posted and told me it is the same without any differences. Also told me that they never get "made in china" parts since they aree a big supplier etc.. I do not know what to do.. is it a good idea to contact the official Infineon distributor here in Greece in order to send some photos for identification?

author: exe
author_rank: Unknown
timestamp: May 06, 2020, 03:17:45 pm
content: Here is a relevant article:https://miscdotgeek.com/genuine-irf510/. So, I can be wrong with my judgement.

author: wraper
author_rank: Unknown
timestamp: May 06, 2020, 03:48:14 pm
content: Quote from: nick#18 on May 06, 2020, 03:11:44 pmIn regards of how it looks, there is nothing wrong with this part. Also their manufacturing date is at least 2 years apart. Part on the left was made in 2016 or also could possibly be from 2006. Part on the right was made in 2018 (possibly 2008).QuoteThat's quite BS since a lot of parts are made in China only. Maybe they meant they don't get them from dodgy places in China or don't sell parts from Chinese brands.

author: WattsThat
author_rank: Frequent Contributor
timestamp: May 06, 2020, 06:17:45 pm
content: Regardless of what the parts look like, any electronics distributor that would deliver mosfets in polyethylene bags would never in a million years get one cent of my money. That is the realm of eBay sellers of recycled electronic trash.They are not a credible distributor if that’s how they delivered the parts.