Mike had firmly riveted Tracy's case down on top of the structural
 tunnel between the pilots feet. This area is subject to a lot of
 vibration
 merely by taxiing around the airport.

 I had to unbolt the top of the tunnel to
 get the case out of there. Took me a couple of hours as one
 button socket head 10-32 head hex had striped out.

 The circuit board is mounted upside down so if a chip wanted
 to fall out it would have no real impediment.

 I could see nothing obviously wrong with the circuitry except for
 one solder bridge to ground on one of the 3 terminal 5 volt regulators.
 It was the center lead and as I recall that is supposed to be ground
 anyway.

 Both computer chips were firmly in the sockets.

 This EC2AX computer was built in 2001 so the electrolytic caps could
 be deteriorated.

 Apparently it was updated in 2003. These computers have mechanical
relays
 so it is not a good idea to bolt them down. Dave Leonard suggested
shock
 mounts and that is what I am going to do. I'll drill the rivets out
 and mount it on rubber isolators.

 IMHO the 10-32 socket button head screws are best replaced
 with normal socket heads. Too bad I cannot find hex heads in 10-32.

 I'll fly it for awhile and see if this fixes the problem.

 Paul Lamar

Hey Paul;
Have considered hot-glue/rtv/silicon/conformal coating to try to keep
those PLCC and other components in place and protected?
Cheers
Cary

I hesitate to do that as Tracy needs to pop the chips out of there
for reprogramming. I don't think those old style chips can be re-flashed
while still in the circuit. I am guessing but embedded computer chips
have come along way since 2001.

I don't know what the history of this EC2 computer really is.
What was done when and why it was done. Perhaps
Tracy has records on it he can share with me.


Paul Lamar



Paul,  For small screws check out e-bay seller  a_future_heirloom
They sell plated, alloy, and stainless screws  in packages of like 6
pieces for 98 cents.  I recently bought some 2-56 hex head alloy screws
for an HO train engine from them. First go to their online e-bay store
and find the part. Then if it is not presently in the auction you e-mail
them at
afutur_hzi3807ojfx@members.ebay.com
<mailto:afutur_hzi3807ojfx@members.ebay.com>.   They will then list the
item in the auction.  I basically ordered a similar screw on the auction
after checking with their e-mail and attached a note of what I really
wanted shipped.  The alloy screws appear well made so I got a variety.
Delivery was on the third day.

george


I found a company in RI http://www.jamestowndistributors.com/
    
10-32 S/S Hex Caps Fine Thread.
I have an order in but they cannot send it $5 flat rate USPO.
I am awaiting an email from them on what it is going to cost
to ship it from the east coast to the west coast.
These companies frequently try to get rich on the shipping.
Summit Racing is a good example. Come on price but $10 surcharge
for shipping not including the actual cost of shipping.

Paul Lamar