On Thu, 17 Jul 2014 08:02:17 -0600, Randy Day
wrote:

In article ,
says...

[snip]

Bingo. I measured near infinity on all the pin connections on a known
good cartridges. I'm not a big fan of COB (chip on board)
construction, but I don't think that was the problem. COB failures
usually cause opens, not shorts. So, my guess(tm) is either crappy
constuction (adjacent wire bonds shorted), or static damage.

Tin whiskers from cheap chinese ROHS solder...

What solder? The chip is glued to a gold plated PCB (no tin) without
any other components. See lousy photo at:
http://inkjet411.com/?page_id=35
In my experience with tin whiskers (in GE MSTR radio cavities and tin
plated connectors), the whiskers are "blown" by even the smallest
voltage across them. In this case, all 4 pins have a fairly large
(3.3v) potential between adjacent pins at various times, which is more
than sufficient to blow any tin whisker. Maybe a broken piece of wire
left around the chip during wire bonding, could easily produce a
short.

I wonder how they do these? Emulation?
http://www.ebay.com/itm/like/160698015099
http://cmyshow.en.ec21.com/Continuous_Bulk_Ink_Supply_System--1638985_1795969.html

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558