Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: FT-757 GXII Problem  (Read 1669 times)
VU2XMX
Member

Posts: 3




Ignore
« on: June 27, 2010, 06:33:17 PM »

Hi !
This regarding a big problem I got into with my FT-757 GXII. I use it with ATU FT-757AT. The cable to connect band data and to supply the antenna tuner is homebrew where the wire from pin 7 (rig side, same number on tuner side) is exposed with no insultation for some 7mm from the connector (rig side). I accidentally shorted this wire to ground while connecting my radio to station ground Sad . This has shutdown the rig - no display, nothing. On switch on the meter needle goes full scale.

This pin 7 supplies 13 vdc to the antenna tuner and it has, I guess, 500mA limit. Could you tell what part/component of the circuit in the radio is damaged?
I love this radio and wish it comes alive again. I promise I will take utmost care of it if it come to lfe again !

I have the circuit diagram for the radio.

73,
Prem VE6XMX (also, Vu2XMX)
Logged
WA9FVP
Member

Posts: 37




Ignore
« Reply #1 on: June 27, 2010, 08:28:04 PM »

First press in both push buttons on the rear panel and turn off the radio for a minute.  The CPU will reset and display 7.000 MHz when you turn it on.  If it's OK, don't forget to press out the buttons.

If that doesn't work;

There's a 5 volt, 3 terminal regulator (78L05) Q68 and an 8v 3 terminal regulator (UPC7808) Q1.   Make sure that both regulators are getting 13v.  If not,  check the 13 volts on the Local board (J10 pin 2) it feeds off the PA board on J3 pin2.  It the 13 volts is there, remove the Local Unit and check for burnt copper tracks on the local unit.  If not, you'll have to check the PA unit for burnt tracks.   
Logged
VU2XMX
Member

Posts: 3




Ignore
« Reply #2 on: June 28, 2010, 10:07:20 AM »

Thanks, so precise steps!
I am eager to get home and try the easy part out right away! If it  doesn't work, the  other steps you have given are are so precise and by following themI should be able to fix it. Will post an update later.

Thanks again,
73
Prem


Logged
VU2XMX
Member

Posts: 3




Ignore
« Reply #3 on: August 16, 2010, 04:31:53 PM »

Hi John!
Thanks a million!
That's exactly what it was. The track must have been blown at some point you have specified. I did not take out the board but just jumpered the voltage source to the other point. The radio is alive again.
73,
Prem
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!