Blew up my motherboard, need help finding a replacement MOSFET - Page 1
Forum section: electronics / general

author: tribat
author_rank: Contributor
timestamp: June 18, 2010, 11:18:00 am
content: So I just learned that you should always check the spacers before you slap a motherboard on the testing bench. Managed to get an extra spacer under the memory voltage switching circuitry and it of course shorted and brokeLuckily the memory sticks survived and went thru memtest86 without problems =)The part that I broke on the board is a TO-252 packaged AP9916H N-Channel switching MOSFET. I've never dealt with mosfets so I have no clue what part I could use to replace it with. Any ideas what I should do? Ordering a single mosfet from places like Digikey or Mouser is probably gonna cost me more than a new motherboard so that's something to consider too I guess :p

author: Hypernova
author_rank: Unknown
timestamp: June 18, 2010, 12:05:13 pm
content: Are you sure that's the only thing broken? It's likely that some other chips on the board have also been damaged.

author: allanw
author_rank: Frequent Contributor
timestamp: June 18, 2010, 06:27:37 pm
content: Quote from: tribat on June 18, 2010, 11:18:00 amQuite on the contrary, Digikey and Mouser will sell you MOSFETs in single quantites at like $1 each. Digikey also has like $2.41 shipping on small orders if you're willing to wait a few days.Try to find a mosfet of the same form factor and similar characteristics as the one you're replacing.http://tw.ic-on-line.cn/IOL/datasheet/ap9916h_254136.pdfThe important specs are: low on-resistance (25 milliohms), 2.5V gate drive (look at the I_d current vs V_DS curves, make sure that the I_d that flows for 2.5V V_G is high). Not really sure what the other two bullet points mean. Also it's kind of risky unless you can find the exact mosfet, but it doesn't seem to be easily available. Also there might be other broken parts.

author: Zero999
author_rank: Super Contributor
timestamp: June 18, 2010, 08:43:34 pm
content: Where do you live?I spent a few minutes searching and found a suitable part in RS Components: SUD40N03-18Phttp://docs-europe.origin.electrocomponents.com/webdocs/059e/0900766b8059e7d8.pdfhttp://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=5057893

author: tribat
author_rank: Contributor
timestamp: June 19, 2010, 09:32:00 pm
content: Quote from: shafri on June 18, 2010, 03:57:32 pmI looked trough some dead boards that I have but none of them had ones with suitable current rating.Quote from: Hero999 on June 18, 2010, 08:43:34 pmOhh sweet! I live in Finland, I'm not quite sure how to go about cheaply acquiring few of those babys

author: Zero999
author_rank: Super Contributor
timestamp: June 19, 2010, 10:42:16 pm
content: RS also exist in Finland.http://fi.rsdelivers.com/product/vishay/sud40n03-18p/n-channel-mosfet-sud40n03-18p-40a-30v/5057893.aspxI couldn't see the price and have no idea whether this is value for money in the country you live in. They come in packs of five which works out at £6.80 after tax and is not a large amount of money.

author: Unknown
author_rank: Unknown
timestamp: June 19, 2010, 10:58:44 pm
content: Note that in some countries vendors like RS and Farnell will sell exclusively to business customers.

author: Time
author_rank: Frequent Contributor
timestamp: June 19, 2010, 11:03:06 pm
content: I guess I take living within a drives distance from mouser for granted.

author: Zero999
author_rank: Super Contributor
timestamp: June 21, 2010, 10:23:06 am
content: Quote from: alm on June 19, 2010, 10:58:44 pmRS and Farnell sell to anyone, I don't know if that's their general policy, there's a filed for company in the form to sign up but I just filled the name of the company I work in. I also get free delivery from RS because my account was created for me by by previous boss so it's registered as a business account. I don't get free orders though because he wasn't silly enough to give me the company credit card details.

author: jahonen
author_rank: Super Contributor
timestamp: June 21, 2010, 10:36:32 am
content: Quote from: tribat on June 19, 2010, 09:32:00 pmYE internationalsells RS stuff in Finland, and you can order things from Farnell via many other companies.Regards,Janne