Try a can of compressed air. The cold air blown directly on an offending
component often reveals the source of intermittent failure.
--
Marc W8SDG
> On Nov 8, 2015, at 9:04 AM, Ignacy Misztal <no9e@arrl.net> wrote:
>
> The unit is mostly SMD. Some connections are only available from the
> bottom. The unit takes so little power that nothing heats up. I tried
> letting it sit until the problem appears, than tapping many points, with no
> change. I tried tracing, but since the element location needs to be
> deduced, and there are many components, a few hr work lead nowhere.
> Ignacy, NO9E
>
> On Sat, Nov 7, 2015 at 8:05 PM, shawn via TenTec <tentec@contesting.com>
> wrote:
>
>> Can you use it with the cover off? If so, I would run it until the problem
>> occurs, then feel and see if anything is hot. Do some voltage checks, see
>> more f any do not check against the manual.
>>
>> If you leave the unit on, but not in TX mode, will it do this? As in,
>> power on for say an hour, then check on tx--is it dead? Am not familiar
>> with unit, but I am wondering if it would isolate anything.
>>
>> Odds are good for a bad solder joint--I would check and reflow. I would
>> not think bad components but blindly replacing in the signal path may find
>> it.
>>
>> shawn kb1ckt
>>
>> Sent from my iPad
>>
>>> On Nov 6, 2015, at 2:43 PM, Ignacy Misztal <no9e@arrl.net> wrote:
>>>
>>> I bought TT715 used from W8EK last year. TT715 does wonders with Elecraft
>>> KX3 (reports 2 S better) but has one problem. After about 10-20 minutes,
>>> the lights are still on but there is not output. W8EK claims it was good
>>> when he emailed to me. TT715 looks new.
>>>
>>> I called TT service a year ago, and they claimed it may take a few hrs
>>> -perhaps more than TT715 is worth. I tried to look for weak points,
>>> tapping, checking with oscilloscope, and after a few hrs I could not find
>>> what is wrong. While a schematic is available,there is no component
>>> placement. Diagnostics is not easy since I have to wait until the
>> condition
>>> occurs.
>>>
>>> Did anyone have a similar problem? Any idea how to fix without taking
>> days?
>>>
>>>
>>> Ignacy, NO9E
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