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Cobra UK 29 LTD ST over voltage

Discussion in 'CB Radio Modifications' started by m3vuv, Apr 21, 2018.

  1. m3vuv

    m3vuv New Member

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    hi all ive gotone of these torepair for a friend,he put it into a waggon and shoved 24 volts into it,now we have no led display,no tx,sounds like the pll is unlocked,now i suspect there is a 7805 voltage regulator that supplies the smd chip that controls the pll etc,trouble is i can see it on the schematic,but cant find it on the radio,any ideas anyone,its not a mod i know but couldnt see where else to post,cheers Paul,m3vuv.


     

  2. nomadradio

    nomadradio Analog Retentive

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    Without a measurement of some sort, this is like shooting in the dark.

    Do you have power on the PLL chip's 5-Volt pin? I don't think we have any component-layout or schematic data on UK model radios here. Only the USA versions.

    73
     
  3. sonoma

    sonoma Sr. Member

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    #3 sonoma, Apr 21, 2018
    Last edited: Apr 21, 2018
  4. m3vuv

    m3vuv New Member

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    well,acording to the parts list the 5v reg im after is a kia 7805plisted as ic 105,problem is i cant see where its located,any ideas?,cheers m3vuv.
     
  5. m3vuv

    m3vuv New Member

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    well i found the reg and its ok,noticed there isnt a feed to the meter lamp so time to look at the schematic.
     
  6. sonoma

    sonoma Sr. Member

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    the service manual I posted last night does it cover your radio. was not sure if it covered your radio. that is the only one for that radio I have ever seen.
    I like the trouble shooting info they put on page 5. I have only seen one of these radios back years ago. not very easy to find here in the US..
     

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