Airplane Circuit Board Help

[Crash_Test_Pilot]

Some of the newer business jets have electronic window shades. It's a neat concept, but they stop working all the time and the cost to get one replaced is ridiculous. I'm trying to figure out how to repair.

Everything mechanical is pretty simple, but there's a circuit board that I'm worried is failing. I sent off to a circuit board repair company and they said they couldn't repair because, "it appears most of the components are programmed chips which we cannot support."

I've attached a couple of pictures for review. Here's my question - can anyone repair a circuit board with programmed chips (without having the program)?

 

[MaxHeadRoom78]

Typically the processor IC has been locked off after programming, security fuse etc, method depending on make/type .

 

[JimB]

Here's my question - can anyone repair a circuit board with programmed chips (without having the program)?

The quick answer is no, not possible.

Looking at your pictures, the only programmable chip is the big 100 (?) pin device with the two paper labels.

I cannot read the markings on the two 16 pin chips, my best guess is that these and the discrete components are what provide the interface to the window "mechanism" and it is these items which are more likely to be faulty than the big processor chip.

The whole circuit board appears to be sprayed with a clear lacquer to prevent moisture problems, that can be a problem when working on such boards.

Sorry to be so negative.

JimB

 

[alec_t]

can anyone repair a circuit board with programmed chips (without having the program)?

It rather depends on what the fault is. Without knowledge of the program details and without a schematic of the board the best you can probably do is to inspect the board closely for any physical damage/problem (e.g. loose components, poor wiring terminations, bulging electrolytic capacitors, dry joints, signs of overheating).
A DMM might be able to detect a failed semiconductor device with an in-circuit test. An ESR meter could perhaps identify a failing capacitor.