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Thread: XTS3000 flashing red LED

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    Default XTS3000 flashing red LED

    Again, glad to see this forum back!
    I have several XTS3K radios that have a flashing red LED when turned on and have seen other folks with the same issue.
    The radio will not receive but will transmit.
    This issue is in the RF board, I have seen this on VHF boards only.
    It is not a programming issue.
    I am convinced at this point that it is an injection or power issue and the back-end chip does not see enough IF noise to close the squelch, there is no noise coming from the speaker.
    This is very hard to trouble shoot with the RF board buried as it is, I suspect it is a shorted tantalum cap, I have put this on other forums with no response but figured I would try again....


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    When you say the radio will not RX, are you saying it has NO RX AT ALL (i.e. deaf, dead), or that the red light simply blinks away, and you don't hear anything? i.e. annoying blinking RX light, but no signal heard. But it receives fine, when hearing a strong signal, such as a repeater or something?

    If it's just a case of blinky RX light, but no RX, yes I've had it on mine, too. It's just receiving crap/noise that's in your environment. My XPR7550 is much worse for this type of behavior.

    Also, what are the host/DSP versions of this radio?
    Please elaborate.

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    No this is a failure, these radios will not RX at all (max output from a service monitor has no effect) there is no noise coming from the speaker, this failure has been noted on other forums several times, but with no resolution.
    it is definitely in the RF board, swapping control/vocoder ect, loading new S-rec, programming, alignment has no effect on the failure.
    The host/DSP has no effect, I have replaced the controller and vocoder boards from host 05.xx.xx and DSP R06.xx with 07.71.xx and N08.03.05 for example with no effect.

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    The red LED is signalling a no-lock condition in the receiver. Common failures are oscillator crystals that have gotten banged. Check for correct LO xtals operating at the correct frequencies. Look for easy - obvious first. Xtals are high on the fubar list.
    Retarded Mongoloid on PCP...

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    This could be but I do not think so, an unlock condition is met with a constant error tone from the speaker and an error message on the display (on mod II and III) on the XTS3K and the radio is fully synthesized so I don't think there are any LO crystals.
    This issue must be in the "back end" of the receiver past any points of self diagnostic checks. The blinking red LED is indicating the squelch is open, with the lack of noise in the audio output that leaves the impression there is no noise present which is what the squelch detects to close.
    Last edited by Mogman; 12-30-2017 at 08:23 AM.

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    Check the LO crystal like COM501 suggested (yes there is one). A dead oscillator will produce this symptom.

    Its a lot easier to just replace the RF board with an eBay special than spend any more time troubleshooting.

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    OK I do see the integrated frequency reference, something to try.

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    Quote Originally Posted by Mogman View Post
    This could be but I do not think so, an unlock condition is met with a constant error tone from the speaker and an error message on the display...
    You said you have TX and no RX... from what you are describing I'd say only the receive side of your radio has gone out of lock. Only when TX and RX have both failed do you get a FAIL 001.
    "The Girl Scouts found several hungry REACT members at the finish line..."

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    Mogman

    Check the RXBE output at the ABACUS to ADSIC with an oscilloscope, look for traffic on SBI, DIN and DIN- then check the output of the ADSIC to the DSP SCKR, RFS, RXD. The RXD signal is key as if you have no signal here you will get the RX indicator flashing and no RX, well that's what I have found on the ASTRO25 platform anyway and the XTS3000 setup looks much the same.

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