View Single Post
  #6   Report Post  
Posted to sci.electronics.repair
N_Cook N_Cook is offline
external usenet poster
 
Posts: 5,247
Default Overlay designations & miscellanea

Franc Zabkar wrote in message
...
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...0466ab2db337cd
6b8d9e43e15d4

... 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
--
Please remove one 'i' from my address when replying by email.



I wonder how we can pick up this wildcard structure as in the Philips/XNP
datasheet
http://www.nxp.com/documents/data_sh...2UT_SERIES.pdf
in a Google search


MARKING

TYPE NUMBER / MARKING CODE
PESD3V3S2UT / *U9
PESD5V2S2UT / *U1
PESD12VS2UT / *U2
PESD15VS2UT / *U3
PESD24VS2UT / *U4
Note
* = p : made in Hong Kong.
* = t : made in Malaysia.
* = W : made in China.