Ma audio hk-802sx - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

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 21st June 2010, 02:53 AM   #1
diyAudio Member
 
Join Date: Sep 2006
Default Ma audio hk-802sx

I recieved this amp in for repair. I pulled the first 2 legs of the power supply fets off the board. Leg 3 is still solderd to the board. I also pulled the rectifiers and power supply drivers in this amp.

I still read a short directly across power and ground terminals of the amp.

Wondering what could cause this?? Transformer maybe??
  Reply With Quote
Old 21st June 2010, 04:06 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
D1-d3?
  Reply With Quote
Old 21st June 2010, 04:09 AM   #3
diyAudio Member
 
Join Date: Sep 2006
I lifted 1 side of D1,D2,D3 out of the board And i still read a short between positive and negative terminals
  Reply With Quote
Old 21st June 2010, 04:20 AM   #4
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
If there are no other large diodes and the FETS are out of the circuit, I'd suspect a solder bridge.
  Reply With Quote
Old 21st June 2010, 05:40 AM   #5
diyAudio Member
 
Join Date: Sep 2006
I looked over the entire amp i dont see any solder bridges and no other diodes.

The amp worked for a few secs when it came in but then started drawing high current and reading shorted
  Reply With Quote
Old 21st June 2010, 01:33 PM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Does it read shorted with your meter as well as drawing high current when connected to 12v?
  Reply With Quote
Old 21st June 2010, 03:25 PM   #7
diyAudio Member
 
Join Date: Sep 2006
It reads shorted with my meter. And draws high current with just power and ground hooked up to the amp.
  Reply With Quote
Old 21st June 2010, 03:31 PM   #8
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
It's possible that a primary filter capacitor has failed but that's unlikely. Have you cleaned all of the flux off of the board around the power supply FETs and examined the area with a magnifying glass? Sometimes a tiny thread of solder can be hidden in the flux and cause this problem.
  Reply With Quote
Old 21st June 2010, 03:33 PM   #9
diyAudio Member
 
Join Date: Sep 2006
I will clean it right now and let you know in 5 mins
  Reply With Quote
Old 21st June 2010, 03:46 PM   #10
diyAudio Member
 
Join Date: Sep 2006
Perry,

I cleaned the board . Guess i overlooked the first time i found a solder bridge between legs 1 and 2 for one of the power supply fets.

Next question is The guy had this amp hooked up in his car. He ran 4 guage wire to it. And he added a 2.5 farad cap.

When he had it up and running he said the amp was not as loud as it should be . He said it was only putting out 1/4 of its power and his 600 watt amp was louder.

I told him that his ground and power wire was way to tin for the amp and that his ground wire was also to long (3 ft).

He then told me that the cap he has in the car went from 13.90 volts down to 8 volts with the amp playing and now the cap wont turn on at all and the amp has very low output.

Anything i should check for when putting it back together?
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help with MA Audio HK1000D shawnk Car Audio 12 22nd February 2010 06:30 PM
Ma Audio HK 4000d works but some fets are burnt scrub50187 Car Audio 7 21st April 2008 06:51 AM
MA Audio 802sx help judtoff Car Audio 2 12th November 2007 02:25 PM
MA Audio HK4000 Tom7227 Car Audio 1 16th September 2007 10:07 PM
MA Audio vs. Dayton ZuMbAiU Subwoofers 7 30th January 2006 01:29 AM


New To Site? Need Help?

All times are GMT. The time now is 06:47 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2