LX20-Secret Key Not Valid!

[Ken Ward]

I had to open my LX20 last night to replace both the 9v NiCd which
wasn't holding a charge with a 9v NiMh, and the small watch battery
which was dead. I reassembled it, connected it to the charger, and hit
the ON button.

It starts beeping and displays the message "Secret Key Not Valid!"

I followed the Memory Init routine from the manual, and put in a new
password in the Setup menu, but after I turn it off/on, the error
returns.

What do I need to do now?

Thanks,
Ken

[5Z]

I suspect you send it back and have it resealed. Sounds like you broke
the tamper seal in the device.

It *may* still be usable as an insecure FR, but forget badges or
records.

-Tom

[Marc Ramsey]

5Z wrote:
> I suspect you send it back and have it resealed. Sounds like you broke
> the tamper seal in the device.
>
> It *may* still be usable as an insecure FR, but forget badges or
> records.

Tom is correct, you broke the electronic seal. It needs to go back to
the factory or an authorized agent. Send an email to LX Navigation to
find out what your options are...

Marc

[Ken Ward]

In article >,
Marc Ramsey > wrote:

> 5Z wrote:
> > I suspect you send it back and have it resealed. Sounds like you broke
> > the tamper seal in the device.
> >
> > It *may* still be usable as an insecure FR, but forget badges or
> > records.
>
> Tom is correct, you broke the electronic seal. It needs to go back to
> the factory or an authorized agent. Send an email to LX Navigation to
> find out what your options are...
>
> Marc

The 9v NiCd was no longer holding a charge, so the only way the LX-20
would operate was on external power. Upon investigation I see that when
I opened the case to also replace the original nearly 10 year old
lithium watch battery which supplies power to save settings (name,
glider, units, etc), a micro switch opened.

Whether you're replacing the lithium battery because it is old or
because it has died, you still have to open the case, which opens the
micro switch and invalidates the security code. Actually, it's probably
better that this happened now, instead of in flight, in the middle of
the soaring season. I still have time to get this resolved. The 9v and
the lithium battery lasted for nearly 10 years, so they were due for
replacement. What's the reasoning behind hiding the LX-20 lithium
battery such that it can't be replaced without opening the micro switch?

I hear that there's a DOS application from Filser which resets the
security code, and that this is an issue for a number of secure flight
recorders. That is, there are other units which have a small battery
that when removed for replacement, cause the same problem. How do other
manufacturers handle this?

I note that my home central heating/cooling display uses a pair of
lithiums in parallel, so you can replace them one at a time without
losing the stored program.

Ken

[Marc Ramsey]

Ken Ward wrote:
> I hear that there's a DOS application from Filser which resets the
> security code, and that this is an issue for a number of secure flight
> recorders.

If such a DOS program is being provided to those who are not factory
authorized agents, I would like to hear about it. This would be a
definite violation of the terms under which the unit is approved. If
the case is opened, or the security seal is otherwise broken, the unit
*must* go back to the factory or a designated agent for resealing. The
internal hardware *must* be inspected for possible tampering. Any other
approach would make it trivially easy to subvert the entire system.

> That is, there are other units which have a small battery
> that when removed for replacement, cause the same problem. How do other
> manufacturers handle this?

The usual approach to allow replacement of the lithium cell, is to apply
external power during the replacement. To my knowledge, only the
GPS-NAV allows for replacement of the cell, without opening the case
(and without unsealing the unit). For all other approved flight
recorders using lithium cell (some use long lived rechargeable cells),
when it dies, the seal is lost, and it's time for a trip to the factory.

Marc

[Bruce]

Marc Ramsey wrote:
> 5Z wrote:
>
>> I suspect you send it back and have it resealed. Sounds like you broke
>> the tamper seal in the device.
>>
>> It *may* still be usable as an insecure FR, but forget badges or
>> records.
>
>
> Tom is correct, you broke the electronic seal. It needs to go back to
> the factory or an authorized agent. Send an email to LX Navigation to
> find out what your options are...
>
> Marc
If the LX20 loses power to the VRAM, or the tamper seal triggers it becomes
unusable. It will not boot bast the Secret key not valid message and will not
initialise the GPS, let alone display tasks, and record flights. Very secure.

The 9V battery is reasonably easy to replace as long as you keep the external
power on while you replace the battery. One little philips screw on the external
casing, lever it out of the hole carefully and replace with equivalent. If the
power is interrupted, and the lithium battery is no longer up to the job -
almost guaranteed after 10 years - you are in trouble.

If for any reason you get the dreaded "Secret Key Not Valid" disease your LX20
is in need of recussitation by a certified person. This only takes 20 minutes
with a notebook, and the data cables, and the appropriate software and tools.

Hint, charge it once a month even if you are not using it, they seem to
"hibernate" rather than switch off completely, and there is always a slow drain
on the battery.

Email > - Crtomir Rojnik and company will be able to
help, but shipping it may not be cheap or convenient. Let's not go into how I
got to learn all this...

--
Bruce Greeff
Std Cirrus #57
I'm no-T at the address above.

[Paul Remde]

Hi,

I'm working on getting approval from LX to fix the unit here in the USA as
an agent for LX. If I don't get approved then Ed Hollestelle at Solaire
Canada can definitely do it.

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com

"Bruce" > wrote in message
...
> Marc Ramsey wrote:
>> 5Z wrote:
>>
>>> I suspect you send it back and have it resealed. Sounds like you broke
>>> the tamper seal in the device.
>>>
>>> It *may* still be usable as an insecure FR, but forget badges or
>>> records.
>>
>>
>> Tom is correct, you broke the electronic seal. It needs to go back to
>> the factory or an authorized agent. Send an email to LX Navigation to
>> find out what your options are...
>>
>> Marc
> If the LX20 loses power to the VRAM, or the tamper seal triggers it
> becomes unusable. It will not boot bast the Secret key not valid message
> and will not initialise the GPS, let alone display tasks, and record
> flights. Very secure.
>
> The 9V battery is reasonably easy to replace as long as you keep the
> external power on while you replace the battery. One little philips screw
> on the external casing, lever it out of the hole carefully and replace
> with equivalent. If the power is interrupted, and the lithium battery is
> no longer up to the job - almost guaranteed after 10 years - you are in
> trouble.
>
> If for any reason you get the dreaded "Secret Key Not Valid" disease your
> LX20 is in need of recussitation by a certified person. This only takes 20
> minutes with a notebook, and the data cables, and the appropriate software
> and tools.
>
> Hint, charge it once a month even if you are not using it, they seem to
> "hibernate" rather than switch off completely, and there is always a slow
> drain on the battery.
>
> Email > - Crtomir Rojnik and company will be able
> to help, but shipping it may not be cheap or convenient. Let's not go into
> how I got to learn all this...
>
> --
> Bruce Greeff
> Std Cirrus #57
> I'm no-T at the address above.