Edition 55
Technical Trends - Failure Modes and Modularity
by Bryant Underwood, Public Safety Sourcing, Cassidian Communications

Return to Menu


Exit Reviews:
I was reading an analysis by Bunnie Huang regarding the failure modes of various electronic products after several years of use. The reports are pretty clever and very detailed. Bunnie calls the reports Exit Reviews. The slant of the report is brilliant and one that I would recommend for all products repaired by high-volume operations. This is especially true when you consider the engineering and historical value of the information in improving designs or refining repair processes. Let me share a couple of take-aways from one of the reports on a Samsung Galaxy S-II.

First there was only one failure mode discovered that did not result from some form of abuse. That failure mode related to the logic in the phone needing to sense a ‘wrist snap’ that you have moved the phone from your ear and are ready to terminate the call. That repeated action over years, severely stresses the reference oscillator and the contacts for the board interconnections. That was it. All of the other failures were the result of dropping, collected dust or not replacing the battery when it clearly had no more life.


The battery failure mode was interesting. Bunnie shared a very cool battery troubleshooting trick that is used in China. You remove the battery and lay it on a flat surface and spin the battery. If the battery spins freely, it is bulged and needs to be replaced. Bunnie’s battery failed the test and he kept using the phone. While stuck at an airport, playing a game the battery died but did so in an uncontrolled manner corrupting the flash memory and bricking the phone.

Then there was dust. Take a look at the photo below of the USB/charge connector. It is amazing the phone would charge at all. It is also interesting to consider that this concentration of dust at the charge port may have contributed to the battery failure that finally bricked the phone.


The other aspect about dust that I have found interesting is how many phones I have seen recently where the symptom is no audio and the root cause was dust packed into the pinhole sized microphone sound canal. Quick tip: when you find this problem use a desoldering tool to vacuum the dust from sound canal clear to get the phone working. I would even recommend you do this on every phone you touch to reduce bounce repairs.

Modular Products:

We are all aware that e-waste is a growing issue that is hard to overestimate the growing impact. When a product breaks there will be one small part that fails but all the other components are in good working order. The entire product is often discarded, creating huge waste. The affects of this high generation of e-waste for personal electronics drives higher recurring costs and pushed valuable resources into the trash.

For most mass market products there is some form of recycling that functions to recover working components at a higher level of value-add. For example, in transportation there are salvage yards that recover transmissions, engines and body parts. For desktop PCs and servers major modules like memory of power supplies are recovered and reused. For phones and other personal devices the level of integration has become so dense that this value-harvesting is just not practical. However that same size reduction can be an advantage if matched with a standardized backbone interface. The result would be to speed repair, reuse components and make upgrades trivial.


The most brilliant approach I have seen in addressing this is the concept of PhoneBloks. The short video really must be seen. There is a base that interconnects the LCD interface on one side to functional blocks on the other side. The whole assembly can be customized and repaired with only a T6 driver.

The resistance to this concept is the removal of control of the product from the hardware manufacturers. So you might say, this will never change because no manufacturer will allow their product to be standardized… Well you may be right, except for one trend- the Firefox OS for cellphones. The carriers are terrified that they may become nothing but utilities that provide data pipes. To fight that threat they are partnering to develop a cellphone platform they can control. That platform will focus on HTML 5 and be based on the Firefox OS. We are on the verge of the current seeing the iPhone/Samsung duopoly becoming transformed into a three-way race. For the wireless carriers, they need hardware costs to drop. They want to sell service billing not more plastic and silicon. The technology that is there only barrier that needs close is for a wireless carrier to embrace and implement this form factor for the subscriber units running Firefox. I believe the attractiveness of that decision makes this change inevitable. When that happens, we will have another groundbreaking shift in the personal electronics market. All of this is being driven by e-waste, repair and recurring cost. We are really in a time when change is occurring at a rate faster than large companies can control or anticipate. Sure is fun to watch.

Links:
https://medium.com/people-gadgets/554936428f60
http://www.phonebloks.com/
http://www.youtube.com/watch?v=oDAw7vW7H0c
http://www.mozilla.org/en-US/firefox/os/
RLM
Bryant Underwood manages Public Safety Sourcing for Cassidian Communications, an EADS North America Company in Frisco Texas.

Return to Menu