Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

irf9540 mosfet test(p-channel)
irf9540 mosfet test(p-channel)
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 1st February 2004, 08:16 AM   #1
luv2bass is offline luv2bass  Greece
diyAudio Member
Join Date: Feb 2004
Location: -
Default irf9540 mosfet test(p-channel)

i do all of the following...

"connect the meter negative to the MOSFET's source. This is arrowed in the drawing above which shows the most popular TO220 MOSFETs.

Hold the MOSFET by the case or the tab if you wish, it doesn't matter if you touch the metal body but be careful not to touch the leads until you need to.

First touch the meter positive on to the gate.

Now move the positive meter probe to the drain. You should get a low reading. The MOSFET's gate capacitance has been charged up by the meter and the device is turned on.

With the meter positive still connected to the drain, touch a finger between source and gate (and drain if you wish, it matters not). The gate will be discharged through your finger and the meter reading should go high, indicating a non-conducting device. "

...but when i try to discharge the gate,it doesn't discharge.do you think the mosfet is damaged or do i test the wrong way?

i tried the same for the irf540 and works!!!

p.s. the mosfets(irf540 and irf9540) are part of Rockford 451s amplifier output stage.the problems started when i connected invert polarity the power wires
  Reply With Quote
Old 2nd February 2004, 09:35 PM   #2
ukram is offline ukram  Finland
diyAudio Member
Join Date: Jun 2003
Location: Espoo, Finland
Try measuring the resistance between fet pins. I had some failed fets that had shorts between (all?) pins in my old Onkyo A-8067 amp. That amp was the reason for building my own amp, which has NOT had any problems, about 6 months old now. I still have a bunch of FETs that i bought for repairs. If you get about zero resistance from gate to some other pin, then the FET has certainly failed.
  Reply With Quote


irf9540 mosfet test(p-channel)Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Test for blown body-diode in mosfet? h_a Solid State 2 29th June 2009 07:47 AM
ampli mosfet irf 540 + irf9540 xcicc Solid State 24 20th March 2009 12:10 AM
How to test Mosfet with Multimeter? Ryssen Pass Labs 7 30th August 2008 03:27 PM
How to test mosfet? Nordic Solid State 21 22nd February 2007 07:42 AM

New To Site? Need Help?

All times are GMT. The time now is 04:39 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio