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69814Re: RXTX ensemble Trouble

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  • Jaco Le roux
    Nov 6, 2012
    • 0 Attachment
      Hi Alan,

      All is fine with the resistors, but I have done a test on the IC's.

      USB & 12volt connected

      U11:
      pin1 = 2.63
      pin2 = 2.54
      pin3 = 2.54
      pin4 = 0
      pin5 = 2.54
      pin6 = 2.54
      pin7 = 2.74
      pin8 = 5.05

      U10
      Pin 8 = 0
      Pins 1 and 15 (PTT OFF) = 0
      Pin 2 (from Divider) = 2.5
      Pin 14 (from Divider) = 2.53 (sometimes I measure 5.05 checked for shorts )
      Pin 7 (to OpAmp) Vdc = 2.54
      Pin 9 (to OpAmp) Vdc = 2.54
      Pin 16 (Vdd) Vdc = 5.05
      Pins 1 and 15 (PTT ON) = 5.05

      U6 & U7 ( This is where I found a problem )

      Left IC, Pin 1 Vdc = 0.3
      Left IC, Pin 2 Vdc = 0.3
      Left IC, Pin 3 Vdc = 0.3
      Left IC, Pin 4 Vdc = 0
      Left IC, Pin 5 Vdc = 0.3
      Left IC, Pin 6 Vdc = 0.3
      Left IC, Pin 7 Vdc = 0.3
      Left IC, Pin 8 Vdc = 5.05
      Right IC, Pin 1 Vdc = 0.3
      Right IC, Pin 2 Vdc = 0.3
      Right IC, Pin 3 Vdc = 0.3
      Right IC, Pin 4 Vdc = 0
      Right IC, Pin 5 Vdc = 0.3
      Right IC, Pin 6 Vdc = 0.3
      Right IC, Pin 7 Vdc = 0.3
      Right IC, Pin 8 Vdc = 5.05

      U8 ( Did check for any dry joints just can't find any, re-soldered the board )

      A: Pin 2 Vdc = 2.55
      B: Pin 14 Vdc = 2.50
      C: Pin 7 (R30 hairpin) Vdc = 2.02
      D: Pin 9 (R31 hairpin) Vdc = 2.02
      E: Pin 13 (R25 hairpin) Vdc = (Starts at 2volt then decrease, voltage increase if PCB get's twisted)
      F: Pin 10 (R26 hairpin) Vdc = (Starts at 2volt then decrease, voltage increase if PCB get's twisted)
      G: Pin 12 (R27 hairpin) Vdc = (Starts at 2volt then decrease, voltage increase if PCB get's twisted)
      H: Pin 11 (R28 hairpin) Vdc = (Starts at 2volt then decrease, voltage increase if PCB get's twisted)

      U5

      At U5

      R13 hairpin (wrt regular ground) Vdc = 2.51
      R14 hairpin (wrt regular ground) Vdc = 5.05

      Pin 1 (blue point) Vdc = 5.05
      Pin 2 (yellow point) Vdc = 2.48
      Pin 3 (yellow point) Vdc = 2.52
      Pin 4 (blue point) Vdc = 5.05
      Pin 5 (yellow point) Vdc = 2.5
      Pin 6 (yellow point) Vdc = 2.54 (sometimes 5.05, twist PCB then voltage back to 2.54)
      Pin 7 (regular ground) Vdc = 0
      Pin 8 (yellow point) Vdc = 2.55
      Pin9 (yellow point) Vdc = 2.5
      Pin 10 (blue point) Vdc = 5.05
      Pin 11 (yellow point) Vdc = 2.52
      Pin 12 (yellow point) Vdc = 2.54
      Pin 11 (blue point) Vdc = 5.05
      Pin 14 (blue point) Vdc = 5.05

      Si570

      pin1 = 3.28
      pin2 = 3.28
      pin3 = 0
      pin4 = 1.61
      pin5 = 0.3
      pin6 = 3.29
      pin7 = 3.29
      pin8 = 0.930

      This is it, I hope that there is some good answers for this, I'm tiered of searching for the problem, I would just like to get this thing working.

      I have also changed the 5volt regulator due to some problem it had or got, I have measured it of the PCB and got a 12v output for only a second and then it just go to 0volt.

      Thanks for the help this far.

      73' Jaco de ZS6PX

      --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
      >
      >
      > ----- Original Message -----
      > Subject: [softrock40] Re: RXTX ensemble Trouble
      >
      >
      > > I have checked the output to ground on the 5volt regulator with my DMM and got a 10 Ohm reading. I have lifted all the IC's pins
      > > connected to the 5v track and still find it to be 10 ohms, If I select continuity on the DMM it beeps and give reading of 10ohm.
      > >
      > > This might be the problem I have with the 5volt that only measure in at 1.3volt, even the input side of the 5volt where it should
      > > be 12volt I only measure 3.5volt, I think something is shorting but I can't find where.
      > >
      >
      > Jaco,
      >
      > I was wondering if you had used 10 ohms for R61, 62.
      > Your measurements do not quite support that but, maybe...
      > Check these and the connections where they join to T5 and U10. Maybe a short to ground here.
      > Report, I need to think!
      >
      > 73 Alan G4ZFQ
      >
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