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Help with Resistor value Texas Star DX500

Discussion in 'Amplifiers' started by TonyV225, Jul 17, 2012.

  1. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    I had opened up one of my Texas Star DX500 yesterday because it mysteriously stopped powering up and I knew right away what had to be done as Ive dealt with this before (The $h!++y fuse holders) and the fuses were the original 35 ampers which I could never find so I always replace bad ones with 30 ampers.

    First off I seen the flat metal blades in the glass fuses were warped which I suspected because I have dealt with this bfore with fuses in Texas Stars getting extremely warm. I replaced the fuses and all was good well that was after repairing one fuse holder. Anyways after I grabbed the lid I was getting ready to install it when I seen a dreaded black smoke or soot stain and thought what the hell so I was looking and didnt see anything burnt so I looked at where the lid was smoke stained and sure enough right below that area on the board was a burnt resistor.

    The amp still works so Im asuming this has been this way since purchased the amplifier a few years ago from a forum member because I never ever smelled anything hot or smell that naty stink these resistors and diode emit when they sizzle. now as I said the amplifier still has always worked but I did notice that on the high setting (just the red poer botton depressed) the SWR rockets right up but I dont run them on High anyways and Im a sidebander aswell.

    The location of the burnt resistor is ........Whith the lid or top cover off and the amplifier facing you there are 3 resistors on the left sidr or left center of the board right below and off the right corner of the relay. 2 of them are horizontal and there one right next to them to the left that angled or pretty much vertical and that vertical one is the cooked or fried resistor I am wondering what value resistor this is and what exactly its for if anyone know if could please help me identify the value of this and its purpose in the circuit.



    I have another Texas Star DX500 but really dont want to finagle that beast ouit of its pain in the @$$ mounting spot ;) As I had stated the amplifier has always worked and worked after I repaired the fuses and one of the rediculous fuse holders but for some reason me finding that burn smoke spot on the lid is driving me insane and I just wanna replace it and wanna know what its purpose is ;) Thanks in advance ......Tony
     

  2. QROdx

    QROdx W9WDX Amateur Radio Club Member

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    the only resistors around the relay should be a 68kΩ and a pair of 470Ω

    dx400-dx500_schematic
     
  3. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    can you post a picture tony?


    73
    Jeff
     
  4. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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  5. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    Jeff its C5 on the cb tricks layout pic.
     
  6. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    It shows its a 150PF Cap!! If thats indeed true then boy this one was burnt right up!!! I have to figure out the voltage of this and figure out what its purpose was or is LOL!!
     
    #6 TonyV225, Jul 17, 2012
    Last edited: Jul 17, 2012
  7. AudioShockwav

    AudioShockwav Extraterrestrial Admin
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    That`s part of the Receive amp Tony, are you sure it is c-5?


    73
    Jeff
     
    1 person likes this.
  8. TonyV225

    TonyV225 W9WDX Amateur Radio Club Member

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    Im pretty almost positive but Im gonna double check. I remember the 2 resistors side by side and this off to the left of them right nrxt to them as I described in my post. As big of a black spot on the lid Im thinking that it has to be that cap to create that spot the rubber coating over the cap itself. But as I said there were the 2 resistors side by side then this right next to them on the left. and the recieve amp still wors so Im totally baffled now. LOL!!
     
    #8 TonyV225, Jul 18, 2012
    Last edited: Jul 18, 2012
  9. drollins1989

    drollins1989 New Member

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    hello fellas can anyone help. what is the resistor with the glass diode underneath it? my dx500v needs both them parts and i can,t figure out what they are cause the burnt so bad and not very good at reading schematics. need either part numbers or % of both. these parts are about a inch from were it says a-0 on the bottom of the small board!. the rear board!! and its the closest parts to the black 25v 33uf cap on the edge of the board. anyone can help thanks
     
  10. BJ radionut

    BJ radionut Supporting Member and 6m addict

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    [​IMG]
    [​IMG]
     

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