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

MTX 1501D (old design) power supply issues
MTX 1501D (old design) power supply issues
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
Reply
 
Thread Tools Search this Thread
Old 27th September 2019, 05:58 PM   #11
BumpinYota is offline BumpinYota  United States
diyAudio Member
 
Join Date: Jul 2019
Location: Venice, FL
Well ive discovered something that also makes perfect sense but i hadnt anticipated.

But if you place ground of your oscilliscope to the amp's main ground, then place the probe on the aluminum heatsink with time divide set to 5us and voltage divide to 1v, you can see the ouptut switching wave (57kHz) being induced in the heat sink!!

You would not believe how long i spent trying to find the short to the heat sink...until i momentarily fired up the board on my rubber mat on the desk with the heat sink in my lap a good 6" away! LoL

Last edited by BumpinYota; 27th September 2019 at 06:02 PM.
  Reply With Quote
Old 27th September 2019, 06:13 PM   #12
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Heatsinks aren't always grounded. On some of these amps, there was a small capacitor (0.1uF?) between a screw and ground. You can add one if your amp doesn't have one. Paralleling a 1k resistor with the cap is a bit better because it drains off any DC as well.

This is only to shunt capacitively coupled noise to ground. If you have a bad insulator that's shorting to the heatsink, that's an entirely different issue.
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote

Reply


MTX 1501D (old design) power supply issuesHide 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
MTX 1501D problem power supply yoppi Car Audio 65 15th March 2016 08:51 PM
S-892 power supply issues Nite Car Audio 33 5th October 2012 02:03 AM
power supply issues beamnet Tubes / Valves 6 9th September 2005 11:47 AM
more help, power supply issues theChris Solid State 15 11th April 2003 06:54 PM
help on power supply issues and more! mwmitchell Tubes / Valves 2 16th August 2002 01:35 AM


New To Site? Need Help?

All times are GMT. The time now is 05:57 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki