Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Junior Member
 
Posts: 7
Default Troubleshoot SMPS in Zenith TV...again!!!

Hello Everyone;

Once again I am still having trouble with a Zenith Model: A32B41W (9-2003) TV set...a wire-wound sand block? power resistor (5W, 0.68ohm RX3401) keeps burning up immediatly when the unit is plugged in. I got the schematic and looked over the power supply section and the resistor that connects to the bridge rectifier (DX3401) and supplies the ground (-) is the trouble maker. This is the set that was killed by too much input voltage (240 not 120). I replaced some components including the 470uF (CX3405) main filter cap and couple other resistors. I don't understand what keeps burning this resistor...any ideas???

Would the HOT (1167-01) be responsible for shorting the power resistor?

Also, If you want to have the full (1MB) .PDF schematic for Zenith GB series, contact me through email and i'll send it to you.
Ejohnson1486(at)yahoo(dot)com
Thank You for any help
  #2   Report Post  
Posted to sci.electronics.repair
Tech Data
 
Posts: n/a
Default Troubleshoot SMPS in Zenith TV...again!!!

Did you just forget to mention it or, didn't you change the regulator
and driver transistor yet? That resistor is a surge resistor and the
only thing from keeping the fuse from blowing. The reg. is an STR53041
and I forget the driver number except it's a Motorola. Also, there's a
100uf and a 22uf cap that needs changing and you're done. The other
components in the power supply should be just fine.

  #3   Report Post  
Posted to sci.electronics.repair
Tech Data
 
Posts: n/a
Default Troubleshoot SMPS in Zenith TV...again!!!

I think you can measure pins 3 and 4 for a short but, doesn't matter.
It's bad and so is the driver transistor and the two electrolytics.

  #4   Report Post  
Junior Member
 
Posts: 7
Default

Quote:
Originally Posted by Tech Data
Did you just forget to mention it or, didn't you change the regulator
and driver transistor yet? That resistor is a surge resistor and the
only thing from keeping the fuse from blowing. The reg. is an STR53041
and I forget the driver number except it's a Motorola. Also, there's a
100uf and a 22uf cap that needs changing and you're done. The other
components in the power supply should be just fine.
Hey, I pulled the STR53041 regulator off the board and the replacement .68ohm 5W power resistor didn't burn up this time...now, how do I test this STR53041 regulator? Just to make sure it is bad. I only have an ohmmeter (AKA: multimeter) Thanks, Johnson
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Req; Help to fix dead ATX SMPS no_go Electronics Repair 5 March 11th 06 06:07 PM
SMPS shuts down Sharp 21AG1-S Jason D. Electronics Repair 0 September 23rd 05 02:44 AM
Won't buy another new Zenith Jeff Strieble Electronics Repair 11 December 17th 03 06:01 AM
Zenith PV4657BG SMPS tran. question dwfincher Electronics Repair 1 November 13th 03 05:04 AM
Zenith TV problems Jeff Strieble Electronics Repair 5 July 23rd 03 11:54 PM


All times are GMT +1. The time now is 04:59 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"