Cambridge L-Nav

[Brian Laverick-Smith]

I have a fault with my cambridge version 2 which I
wonder if any one else has experienced. I will try
the agent but in between time .....?
On a recent flight the speed to fly indicator played
up showing full pull up advice with settings Mc 0
speed 45 knots and showing 2 down ! Before this it
has been good for the two years I have had it
It is 15 years old so maybe it has had its day ? [
like me ]

Any ideas folks

Brian K.G.C.
Brian L-Smith Kent England
Brian L-Smith

[David Kinsell]

Brian Laverick-Smith wrote:
> I have a fault with my cambridge version 2 which I
> wonder if any one else has experienced. I will try
> the agent but in between time .....?
> On a recent flight the speed to fly indicator played
> up showing full pull up advice with settings Mc 0
> speed 45 knots and showing 2 down ! Before this it
> has been good for the two years I have had it
> It is 15 years old so maybe it has had its day ? [
> like me ]
>
> Any ideas folks
>
> Brian K.G.C.
> Brian L-Smith Kent England
> Brian L-Smith
>

I had some intermittent problems with an L-NAV recently.
Netto sometimes showed eight knots up sitting on the ground,
winds aloft sometimes showed as extremely high, and of course
the altitude required indication was way off.

There are some connectors between boards that are tin-plated,
and the processor chip was socketed with a socket having
tin-plated pins. Not good design at all for an aircraft
instrument.

Took it apart, reseated everything including the processor,
and also replaced the battery. Not sure which item fixed
it, but works fine now.

-Dave

[01-- Zero One]

LNav 'goofiness' is almost always a depleted battery. --No, won't
help to use a 14 volt battery on it David :-)



Larry

"01" Zero One





"David Kinsell" > wrote in message
:

> Brian Laverick-Smith wrote:
> > I have a fault with my cambridge version 2 which I
> > wonder if any one else has experienced. I will try
> > the agent but in between time .....?
> > On a recent flight the speed to fly indicator played
> > up showing full pull up advice with settings Mc 0
> > speed 45 knots and showing 2 down ! Before this it
> > has been good for the two years I have had it
> > It is 15 years old so maybe it has had its day ? [
> > like me ]
> >
> > Any ideas folks
> >
> > Brian K.G.C.
> > Brian L-Smith Kent England
> > Brian L-Smith
> >
>
> I had some intermittent problems with an L-NAV recently.
> Netto sometimes showed eight knots up sitting on the ground,
> winds aloft sometimes showed as extremely high, and of course
> the altitude required indication was way off.
>
> There are some connectors between boards that are tin-plated,
> and the processor chip was socketed with a socket having
> tin-plated pins. Not good design at all for an aircraft
> instrument.
>
> Took it apart, reseated everything including the processor,
> and also replaced the battery. Not sure which item fixed
> it, but works fine now.
>
> -Dave

[David Kinsell]

01-- Zero One wrote:
> LNav ‘goofiness’ is almost always a depleted battery.

The units have a low-voltage warning built in, so anybody
should be able to tell if that's the problem. You can't really
replace the battery without flexing the boards and renewing
the connections, so it's a bit hard to separate the two.


> --No, won’t
> help to use a 14 volt battery on it David J
>

I least I don't tell people that radios work just great
on 8 volts :-)

Dave




>
>
> Larry
>
> “01” Zero One
>
>
>
>
>
> "David Kinsell" > wrote in message
> :
>
>> Brian Laverick-Smith wrote:
>> > I have a fault with my cambridge version 2 which I
>> > wonder if any one else has experienced. I will try
>> > the agent but in between time .....?
>> > On a recent flight the speed to fly indicator played
>> > up showing full pull up advice with settings Mc 0
>> > speed 45 knots and showing 2 down ! Before this it
>> > has been good for the two years I have had it
>> > It is 15 years old so maybe it has had its day ? [
>> > like me ]
>> >
>> > Any ideas folks
>> >
>> > Brian K.G.C.
>> > Brian L-Smith Kent England
>> > Brian L-Smith
>> >
>>
>> I had some intermittent problems with an L-NAV recently.
>> Netto sometimes showed eight knots up sitting on the ground,
>> winds aloft sometimes showed as extremely high, and of course
>> the altitude required indication was way off.
>>
>> There are some connectors between boards that are tin-plated,
>> and the processor chip was socketed with a socket having
>> tin-plated pins. Not good design at all for an aircraft
>> instrument.
>>
>> Took it apart, reseated everything including the processor,
>> and also replaced the battery. Not sure which item fixed
>> it, but works fine now.
>>
>> -Dave
>

[01-- Zero One]

Actually, I was speaking of the internal battery inside the LNav. It is
a small coin style battery used to retain settings. I have had mine go
south and all sorts of weirdness were the result.



Larry



PS: Dave, maybe you need to run your radios on metric volts or
something. :-)









"David Kinsell" > wrote in message
:

> 01-- Zero One wrote:
> > LNav 'goofiness' is almost always a depleted battery.
>
> The units have a low-voltage warning built in, so anybody
> should be able to tell if that's the problem. You can't really
> replace the battery without flexing the boards and renewing
> the connections, so it's a bit hard to separate the two.
>
>
> > --No, won't
> > help to use a 14 volt battery on it David J
> >
>
> I least I don't tell people that radios work just great
> on 8 volts :-)
>
> Dave
>
>
>
>
> >
> >
> > Larry
> >
> > "01" Zero One
> >
> >
> >
> >
> >
> > "David Kinsell" > wrote in message
> > :
> >
> >> Brian Laverick-Smith wrote:
> >> > I have a fault with my cambridge version 2 which I
> >> > wonder if any one else has experienced. I will try
> >> > the agent but in between time .....?
> >> > On a recent flight the speed to fly indicator played
> >> > up showing full pull up advice with settings Mc 0
> >> > speed 45 knots and showing 2 down ! Before this it
> >> > has been good for the two years I have had it
> >> > It is 15 years old so maybe it has had its day ? [
> >> > like me ]
> >> >
> >> > Any ideas folks
> >> >
> >> > Brian K.G.C.
> >> > Brian L-Smith Kent England
> >> > Brian L-Smith
> >> >
> >>
> >> I had some intermittent problems with an L-NAV recently.
> >> Netto sometimes showed eight knots up sitting on the ground,
> >> winds aloft sometimes showed as extremely high, and of course
> >> the altitude required indication was way off.
> >>
> >> There are some connectors between boards that are tin-plated,
> >> and the processor chip was socketed with a socket having
> >> tin-plated pins. Not good design at all for an aircraft
> >> instrument.
> >>
> >> Took it apart, reseated everything including the processor,
> >> and also replaced the battery. Not sure which item fixed
> >> it, but works fine now.
> >>
> >> -Dave
> >

[Pete Startup]

And the wierd stuff starts LONG before the battery
reaches the low voltage level that gives the warning!

Pete

[Pete Startup]

And the wierd stuff starts LONG before the battery
reaches the low voltage level that gives the warning!

Pete