Replacing a defective T4 trim switch in my 14mz...

[hpilotrc]

Here are some pics in various stages of dissassembly:

Removing printed circuit boards without using adequate static discharge protection can permanently destroy sensitive electronic components and render you 14mz useless. Do not attempt dissassembly unless you are qualified to do so!!!



RF Module printed circuit board removed:


RF Module plastic pcb holder removed:


Main printed circuit board removed showing black plastic LCD holder still intact:


Top of main printed circuit board. Two ball grid array IC's (the main processor's) can be seen.


Bottom of main printed circuit board:


LCD Display in plastic holder is removed but the touch panel, two upper metal brackets, and associated potentiometer assemblies still have to be carefully removed. Then their are a bunch of screws (2 extra long ones) that have to be removed before the board can be pulled out. My transmitter happened to have at least one screw (you can see it) missing from production! It just happened to be where the faulty switch was.






Finally after removing the black LCD Display holder, glass touch panel, and some upper frame parts you are able to get to the trim switch assembly. The black plastic rocker trim switches are also different depending on the position they are installed in and will fall out easily! The trim switches are very small smd switches and care needs to be taken when removing them....




Michael

[pqr]

My T4 is also playing up - sometimes it goes left, sometimes it doesn't. Looks very interesting, but I have a basic question please - how o you get the back off? I can't see any screws heads at the back even after taking the rubber strips off

Regards, Phil

[hpilotrc]

Phil,

Sorry for taking so long to answer you.

First you have to use a metric allen wrench to remove the bottom 4 cap screws. Then use the same wrench to remove the 4 screws around the black plastic antenna mount - and one each (silver color) left and right for the top switch clusters. You should now have 10 screws removed.

The switch clusters can gently be pulled up from the end of each corner and allow just to rest as is (don't disturb the multiple sets of wires). Remove the black antenna mount.

Now at the top you will see 6 more small screws. Two small small Phillips at each end, 2 small silver Phillips about 1/3 in, and 2 larger black phillips near the middle where the antenna mount piece is.

Once you remove these 6 (total of 16) you will be able to carefully lift the back cover off. The back cover has 3 sets of wiring harnesses connected to it. These need to be gently removed using your nail or a small screwdriver to gently pry apart. You may be also able to remove by gently tugging and rocking the harness using your fingers...but be carefull not to break anything!

There is a lot more to do before you are able to get to those hidden trim switches though!

Hope this helps!

Michael

[pqr]

Hi Michael, Thanks for full explanation. A lot of work but I guess you end up knowing the insides of the Tx by the end :-|

Thanks again

[mineiro]

Hi,
Good job! I have the same problem with my Futaba T10C . As per your pics, my dead trim switches are exactly the same of yours 14MZ.
Could you please tell where you found the spare switch? I searched all around the web but I could not find them... :o(
Many thanks!!

[hpilotrc]

You can get any of the parts including the spare switches from Hobby Services in Illinious.

Michael