On Thu, 07 Oct 2010 01:51:18 -0400 "Michael A. Terrell"
wrote in Message id:
:


D Yuniskis wrote:

Hi Neil,

nesesu wrote:
On Sep 29, 2:54 pm, D Yuniskis wrote:

I come across a fair number of "defective" iPod "stereos"
(countertop boxes into which an iPod is docked). Is there
something intrinsically bad with these (besides being
crappy consumer kit) that drives these failures?

(e.g., the docking and undocking of the iPod without, perhaps,
adequate protection on the interconnect signals)

Well, if it is like many cordless phones, placing the handset onto the
base while carrying a large static charge will scramble the base
operation. On mine I need to unplug the wall wart from the base unit
to restore operation. Unfortunately, the base always faults to the OFF-
LINE state and puts a high level of receiver noise on the line and the
only indication that it is not working is a). no calls received and b)
picking up a wired phone greets you with the high level noise.
I have repaired lots of equipment that has no factory installed ESD
protection on the user interface and usually has a damaged interface
chip or device. Most of these devices were industrial and the designer
should have known better.

Most of these devices seem to have "sticky" (persistent) failures
when I encounter them. I.e., it is not a transient issue associated
with some action on my part.

For example, I have a unit, now, that runs well for "some amount of
time" and then *appears* to keep running -- though any attempts to
interact with it (the "dock") are ignored. E.g., withOUT an iPod
docked into it, I can select the "RADIO" funtion, tune a station
using the up/down buttons, adjust the volume, etc. The radio
will play as expected. Some time later, an attempt to alter the
volume or change the station will be totally ignored. Or, the
device might power itself *off* unprovoked.

I.e., it is as if the processor in the thing has crashed and:
- left things "as is" (in the case where the radio keeps playing
but buttons are ignored)
or
- crashed and "reset" all the I/O to "off" in the process.

Behaviors on other devices have been similar. It is as if
ESD has toasted something internally so that it only marginally
works -- or works temporarily.

shrug Most of these aren't worth the time to fix. I was
just curious as to why so man of them -- different models,
different manufacturers, etc. -- were exhibiting the same
sorts of general failures.


Lead free solder.

+ Chinese manufacturing.