help with semiconductor identification

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midhurstman
Posts: 1
Joined: Mon May 04, 2020 8:30 am

help with semiconductor identification

Post by midhurstman » Mon May 04, 2020 9:42 am

Good morning to all.
By way of introduction, I have joined the forum as I am desperate for an answer to what I expect many electronics specialist will find a very basic question. I am a retired mechanical engineer with a little electronics knowledge gained from an enquiring mind, I feel that the forum membership will be very interesting and helpful to me.

I have spent hours trying to identify what could be an IGBT on the heatsink of a Sharp induction hob Main board. The photo shows, from left to right a bridge rectifier, two identical 3 pin items ( these are the culprits) and a definite IGBT (H20 R12 03). The hob blew the 20 amp fuse and it looks to me like the two unidentified items also, they both show open circuit on the multimeter. The numbering on both is G281H125DF and B V5 632 and no amount of online searching recognises these numbers for me to get replacements. Can anyone help please, are the two unidentified semiconductors also IGBT's ? If so, what alternative spec would be acceptable replacements. I should add that Sharp cannot help me with supplying a new complete board (it's only 4 years old!) or offer help identifying the components.

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The site wouldn't accept the file size of my image so I have used photobucket, please check on the link.
https://app.photobucket.com/u/midhurstm ... 4b271239ef

Thanks in advance to anyone who replies. Barry

David
Posts: 220
Joined: Sun Oct 04, 2015 6:18 pm

Re: help with semiconductor identification

Post by David » Sat May 09, 2020 5:25 pm

Hello
Hmmm … I was rather surprised that you cannot find suitable IGBTs on Google. Lets try another way.

Most customer electrics are very broadly similar to those made by other manufacturers For example, have a look at toasters - they are virtually identical when he cases are removed!

You might like to explore the net looking for "hob components" and mentioning the number of rings, and their individual or total current demand. These components are reasonably cheap - a few £s each - and you can keep some in case you have a whoops by connecting anything in reverse!

Whenever you have a fault in a circuit which uses significant power, don't forget that the other power using devices will probably also be stressed. Therefore it is a very good idea to change all of the IGBTs, bridges, and big capacitors (blue in your pic).

If you did not want to do this yourself, you can always call in a professional, but from your comments you obviously want to DIY. Please, please remember that you are dealing with mains current, so take the greatest care. Use PPE, and try using a socket strip so that you can be out of the room when you switch on for the first time. Don't forget to use heat sink material between semiconductors and heatsinks.

Hope this helps.

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