Here is the procedure from the KLN-89B install
manual for putting your unit into the maintenance mode to adjust many settings
that we mere pilots should never be allowed to adjust <giant grin>!
Per the KLN-89B installation manual: "To enter the
maintenance pages, the MSG button must be depressed before the unit is turned on
and continue to be depressed for 10 seconds (+/- 2 seconds) after turn on. At
the end of the 10-second period, release the MSG button for 1 second and
momentarily press the button again. Following this sequence, the unit will
automatically enter the Maintenance (MNT) pages."
This tip courtesy of Beech Lister and B55/H35 owner, Mike
The KLN94 may be similar. To be sure, download
the KLN94 install manual HERE
KLN-89B Internal Memory
Does your KLN-89B take a long time to acquire satellites
for navigation? Are you getting error messages like: "user data lost", "Error
0008", hardware failure"? Well it could be that your internal memory battery is
dead! Hey, what do you want, it's probably been in service for over 5 or 6
So, if you have a little CSOB talent with a screwdriver,
voltmeter and soldering iron, you might be able to avoid that, possibly $250,
trip to the avionics shop and put that money toward a better use, like 70-80
gallons of 100LL!
Beech Lister and B55/H35 owner, Mike
T. (with an assist from John P.) recently successfully replaced his KLN-89B
internal memory battery. Here is their pirep on how they did it and the source
of the battery:
With a lot of patient hand-holding from John P, this morning I replaced the
memory backup battery in my KLN-89B. Apparently the operation was successful, as
the receiver booted up OK when it was put back in the aircraft.
The battery itself is a Tadiran TL-5104/P, available from retail suppliers
Newark for about $8. (The "P" means "axial leads," which is the variant
you'll need.) It's a AA lithium battery, 2100 mAh and 3.6v, made especially as a
The battery is soldered into the main circuit board. But it's adequately
accessible by simply removing the 89B's top panel -- six screws. Soldering (and
gluing) the replacement battery takes some finesse with a fine-tipped iron, but
it's doable. (Gluing: The barrel of the battery is glued to a connector using
what appears to be silicone sealant or similar; you'll need something similar.)
The soldering itself would be much easier if one worked on the backside of the
circuit board. But it looked like this would require disassembling the receiver
in a big way, and I was worried that that operation might cause problems.
Background: I powered-up the 89B recently and encountered several error
messages, including " Error 0008" and "hardware failure" and "user data lost."
The 89B install manual says 0008 can be a dead battery, but I hear it
can also be a RAM failure or other problems. I wasn't sure it was just a dead
battery because the receiver had worked perfectly a few weeks before. But
putting multimeter across the battery showed zero volts.
(BTW, Tadiran says this battery has a 20-year shelf life. It has introduced a
2300 mAh battery that it says replaces the 5104, but other than the higher
capacity, the two batteries are the same and there's no reason not to use a
5104, the company told me.)
John's 89B showed different symptoms when its battery started to whither. He
said it took a long time to acquire satellites. I don't think he saw the 0008