This is a slightly outdated report, but I am writing this for completeness.

The broken infrared QPD (Q3000 SN3), which had been determined to be broken and was then removed from TMSY on 7th of March 2013 [1], was inspected at the lab. As originally suspected [2], indeed the 1st segment is not 'diode-ing' any more and it shows a small resistance of 2.8 Ohm regardless of the polarity. There is no obvious sign in the appearance of the diode. The rest of the segments looks quite healthy and exhibits a usual voltage drop of 0.44 V. Though interestingly the broken segment is still able to produce photo current when it is illuminated by a flashlight.

BTW, don't be confused by this report --- this is different from the newly broken QPDs which reside in HAM3 [3].

[1] LHO alog 5716 "A new PZT mirror installed at ISCTEY and red in-vac QPD swapped on TMSY"
[2] LHO alog 2865 "TMSY red QPD damage report"
[3] LHO alog 5937 " HAM3 ISC IR QPDs are likely broken, in-vac cabling error, IO QPD should be OK"