RF punch 800a2 channel repair question - Page 2 - 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 10th May 2013, 06:37 PM   #11
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Do you have DC on the output terminals of the defective channel?

Do any of the power supply FETS from the defective side test leaky or shorted?

Are any of the gate resistors for the power supply FETS in the defective channel shorted or out of tolerance?

Have you checked the drivers for the power supply?

Is the amp making rail voltage?

Is the amp making regulated voltage?

Do you have any solder bridges on the pads of the removed FETS in the defective channel?
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 11th May 2013, 04:48 PM   #12
chipper is offline chipper  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Los Angeles
Send a message via MSN to chipper Send a message via Yahoo to chipper
this is the side that heats up
Attached Images
File Type: jpg DSCN0439.jpg (996.6 KB, 40 views)
__________________
Feel the PUNCH
  Reply With Quote
Old 11th May 2013, 04:58 PM   #13
chipper is offline chipper  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Los Angeles
Send a message via MSN to chipper Send a message via Yahoo to chipper
shorted channel. I'll have voltages in a bit i need batteries for my meter.
Attached Images
File Type: jpg DSCN0438.jpg (985.4 KB, 39 views)
__________________
Feel the PUNCH
  Reply With Quote
Old 11th May 2013, 05:26 PM   #14
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
I think maybe you should get those source resistors back in as well as the output FETS.

Then check the protection circuits and make sure you don't have any shorted transistors or diodes.

You will have to check the gate resistors and various smd resistors to make sure none are shorted or out of tolerance.

You need to repair the output section first.
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 11th May 2013, 05:40 PM   #15
chipper is offline chipper  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Los Angeles
Send a message via MSN to chipper Send a message via Yahoo to chipper
Quote:
Originally Posted by seankane View Post
I think maybe you should get those source resistors back in as well as the output FETS.

Then check the protection circuits and make sure you don't have any shorted transistors or diodes.

You will have to check the gate resistors and various smd resistors to make sure none are shorted or out of tolerance.

You need to repair the output section first.

So there's a chance there may not be anything wrong with that bank of power supply fets? When I used the batts from out tv remote, I checked the gate voltage and got a steady 5.36vdc on each fet and checked the voltage going into the amp and it was at 13 voltages.

I also noticed the power supply has mixed mosfets 4 mtp75n05hd and 4 irf3205. Just thought I'd throw that out there.
__________________
Feel the PUNCH
  Reply With Quote
Old 12th May 2013, 01:37 AM   #16
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Is the side thats heating up the side with the IRF3205's and has been repaired?
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 12th May 2013, 01:40 AM   #17
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
This amp does not have separate power supplies. The power supply FETS all need to match.

Since its been repaired, I think it would be a good idea to go through the power supply completely for the amp to be reliable.
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 12th May 2013, 01:58 AM   #18
chipper is offline chipper  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Los Angeles
Send a message via MSN to chipper Send a message via Yahoo to chipper
Quote:
Originally Posted by seankane View Post
This amp does not have separate power supplies. The power supply FETS all need to match.

Since its been repaired, I think it would be a good idea to go through the power supply completely for the amp to be reliable.

I really have to now I popped a 75n05hd by accident when I was probing around in the power supply. Amp was still on after that happened! Like a piece of the mosfet just blew off and scared me sh#tless! I'm going to replace the whole thing and see if that eliminates the one bank of fets heating problem. And move on to the channel.
__________________
Feel the PUNCH
  Reply With Quote
Old 12th May 2013, 02:43 AM   #19
diyAudio Member
 
Join Date: Mar 2007
Location: Columbus, Ohio ^
I agree with Sean, the power supply FETs need to match & need to go through the power supply thoroughly for reliability. You need to do that now anyway, check the drivers & gate resistors thoroughly, as maybe that was overlooked during a previous repair causing the uneven heating of one bank.

If you have to order parts, make sure you order gate resistors & driver transistors as there cheap, if you don't already have extra.

Main reason for me posting here is to say be careful when you got the back off testing stuff, FETs can blow apart & throw pieces of themselves violently, could really mess up an eye. I had some close calls over the years & highly recommend wearing safety glasses when the backs off & the amp has problems.
  Reply With Quote
Old 12th May 2013, 03:30 AM   #20
diyAudio Member
 
Join Date: Jun 2012
If the Amp has IRF3205's in it right now what ohm gate resistors does it have in it??
  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
rockford fosgate punch 800a2 non working chipper Car Audio 8 27th May 2012 09:13 PM
Rockford Fosgate Punch 800a2 seankane Car Audio 3 25th June 2011 05:18 AM
Rockford Punch 800a2 seankane Car Audio 28 5th April 2011 01:27 AM
punch 800a2 $100?? chipper Car Audio 6 8th July 2010 06:21 AM
Assembly/mechanical question RF Punch 45HD gisewhcs Car Audio 6 19th February 2010 01:08 PM


New To Site? Need Help?

All times are GMT. The time now is 12:44 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