Overlay designations & miscellanea
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From: N_Cook on 7 May 2010 06:19 I thought I'd messed up the USB lead of my HP 1020 laserjet , measuring voltages etc, trying to learn about USB function. Turned out I must have strained a USB A to B adaptor and nothing wrong with the printer. Is one rule of thumb (for a suspect USB connection) that a maximum USB insertion force of 250 gram is too low and above 450 gram is generally good ? ( I later went around a number of leads /connectors, adaptors with the kitchen scales). 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 ? 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 D13 AZZ23C8V2 Diode SOT23 dual zener 8.2V 0.3W, 3 pin related? 2 land device marked WU1 found WU BZX284-B4V3 Phi I SOD110 0.4W zener 4.3V E24 �2%, 2 pin related ? Generally do truncated 3 and 4 character topcodes have any relation to the full code ?
From: Michael A. Terrell on 7 May 2010 14:42 N_Cook wrote: > > I thought I'd messed up the USB lead of my HP 1020 laserjet , measuring > voltages etc, trying to learn about USB function. Turned out I must have > strained a USB A to B adaptor and nothing wrong with the printer. Is one > rule of thumb (for a suspect USB connection) that a maximum USB insertion > force of 250 gram is too low and above 450 gram is generally good ? ( I > later went around a number of leads /connectors, adaptors with the kitchen > scales). > 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. 'E' is often used to indicate a connection off the board. They are probably there for automated testing in a 'Bed of Nails' (AKA: Pogo Pins) test fixture during the manufacturing process. More and more manufacturing is moving to this method where boards are handled by machines from the time the blanks are loaded into a pick & place machine, till they are ready to be installed in a product. > There were 2 unmarked green 2 land lumps on the USB lines marked VR > on the overlay, bidirectional transient suppressors ? > 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 > D13 AZZ23C8V2 Diode SOT23 dual zener 8.2V 0.3W, 3 pin > related? > > 2 land device marked WU1 > found > WU BZX284-B4V3 Phi I SOD110 0.4W zener 4.3V E24 �2%, 2 pin > related ? > > Generally do truncated 3 and 4 character topcodes have any relation to the > full code ? No. They match the component's location on the schematics and B.O.M. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: N_Cook on 8 May 2010 03:53 Michael A. Terrell <mike.terrell(a)earthlink.net> wrote in message news:eLSdnTz02p5rw3nWnZ2dnUVZ_v6dnZ2d(a)earthlink.com... > > N_Cook wrote: > > > > I thought I'd messed up the USB lead of my HP 1020 laserjet , measuring > > voltages etc, trying to learn about USB function. Turned out I must have > > strained a USB A to B adaptor and nothing wrong with the printer. Is one > > rule of thumb (for a suspect USB connection) that a maximum USB insertion > > force of 250 gram is too low and above 450 gram is generally good ? ( I > > later went around a number of leads /connectors, adaptors with the kitchen > > scales). > > 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. > > > 'E' is often used to indicate a connection off the board. They are > probably there for automated testing in a 'Bed of Nails' (AKA: Pogo > Pins) test fixture during the manufacturing process. More and more > manufacturing is moving to this method where boards are handled by > machines from the time the blanks are loaded into a pick & place > machine, till they are ready to be installed in a product. > > > > There were 2 unmarked green 2 land lumps on the USB lines marked VR > > on the overlay, bidirectional transient suppressors ? > > 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 > > D13 AZZ23C8V2 Diode SOT23 dual zener 8.2V 0.3W, 3 pin > > related? > > > > 2 land device marked WU1 > > found > > WU BZX284-B4V3 Phi I SOD110 0.4W zener 4.3V E24 �2%, 2 pin > > related ? > > > > Generally do truncated 3 and 4 character topcodes have any relation to the > > full code ? > > > No. They match the component's location on the schematics and B.O.M. > > > -- > Anyone wanting to run for any political office in the US should have to > have a DD214, and a honorable discharge. The "E" were not all the same physical size, one was quite large. Did not try a probe on the central material but matt black , ie non metalic. If they were in fact inductors what subclass ?, there were other items marked "L" for inductors on the same board
From: N_Cook on 8 May 2010 04:15 So my proper Googling for D132 ,in this case, should be of form "D132" AND "datasheet" "part marking" OR "top code" OR "topcode" OR "top mark" OR "topmark" OR "marking" in the searchbox
From: Franc Zabkar on 8 May 2010 04:22
On Sat, 8 May 2010 09:15:09 +0100, "N_Cook" <diverse(a)tcp.co.uk> put finger to keyboard and composed: >So my proper Googling for D132 ,in this case, should be of form > >"D132" AND "datasheet" "part marking" OR "top code" OR "topcode" OR "top >mark" OR "topmark" OR "marking" > >in the searchbox IMHO, adding "filetype:pdf" in place of "datasheet" would be better: Try this: http://www.google.com/search?q=diode+D132+marking+filetype%3Apdf BTW, I have no answer to your question regarding wildcards. It appears that Google parses the asterisk instead of searching for it. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |