On Fri, 7 May 2010 11:19:24 +0100, "N_Cook" put
finger to keyboard and composed:

Anyway inside the printer there were 6 unmarked 2 land SMD lumps marked on
the overlay as E1 to E6 , is E a designation for fuse?, all were 0 ohms
across.

There were 2 unmarked green 2 land lumps on the USB lines marked VR
on the overlay, bidirectional transient suppressors ?

USB ports have short circuit current protection. I believe some may
implement this via polyswitches, or some similar device, eg PTC
resistor (?). Are these devices in series with the supply pins?

and 2 SMD contacting the USB lines marked CR, presumably rectifiers, but can
anyone identify with more certainty

4 land device marked topmark D132
found on topcode listings

CM1213 1, 2, 4, 6 and 8-Channel Low Capacitance ESD Protection Arrays
http://www.datasheetarchive.com/pdf-...DSA-127548.pdf

Yours would be the CM1213-02Sx 2-channel array (D132 marking code). I
suspect that it would be providing ESD protection on each of the D+
and D- pins.

2 land device marked WU1

FWIW, this forum thread ...

http://www.monitorlab.ru/forum/viewt...b8d9 e43e15d4

.... suggests that, in a HP 1020, the WU1 part may be a ...

PESD5V2S2UT Phi A SOT23 Uni-directional ESD Protection 5.2V:
http://www.nxp.com/documents/data_sh...2UT_SERIES.pdf

However it is a 3-pin device.

Generally do truncated 3 and 4 character topcodes have any relation to the
full code ?

In the D132 case, it appears to be true.

13 - 1213
2 - -02


- Franc Zabkar
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