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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                  ------------

                                 SCHEDULE 13G/A

           INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
              RULES 13d-1 (b), (c) AND (d) AND AMENDMENTS THERETO
                           FILED PURSUANT TO 13d-2 (b)
                                (Amendment No. 1 )*


                              PDF Solutions, Inc.
- --------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
- --------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    693282105
- --------------------------------------------------------------------------------
                                 (CUSIP Number)

                               December 31, 2002
- --------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

      |_|   Rule 13d-1(b)

      |_|   Rule 13d-1(c)

      |X|   Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                         (Continued on following pages)

                               Page 1 of 16 pages

CUSIP No. 693282105 Page 2 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) U.S. Venture Partners IV, L.P. ("USVP IV") - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 538,750 shares, except that Presidio Management Group IV, L.P. ("PMG IV"), the general partner of USVP IV, may be deemed to have sole voting power with respect to such shares, and William K Bowes, Jr. ("Bowes"), Irwin Federman ("Federman"), Steven M. Krausz ("Krausz") and Philip M. Young ("Young"), the general partners of PMG IV, may be deemed to have shared voting power with respect to such shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY See response to row 5. OWNED BY -------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 538,750 shares, except that PMG IV, the general partner WITH of USVP IV, may be deemed to have sole dispositive power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared dispositive power with respect to such shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER See response to row 7. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 538,750 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.3% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* PN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 3 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Second Ventures II, L.P. ("SV II") - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 65,626 shares, except that PMG IV, the general partner of SV II, may be deemed to have sole voting power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared voting power with respect to such shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY See response to row 5. OWNED BY -------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 65,626 shares, except that PMG IV, the general partner WITH of SV II, may be deemed to have sole dispositive power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared dispositive power with respect to such shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER See response to row 7. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 65,626 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.3 % - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* PN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 4 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) USVP Entrepreneur Partners II, L.P. ("UEP II") - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 18,749 shares, except that PMG IV, the general partner of UEP II, may be deemed to have sole voting power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared voting power with respect to such shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY See response to row 5. OWNED BY -------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 18,749 shares, except that PMG IV, the general partner of UEP II, may be deemed to have sole dispositive power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared dispositive power with respect to such shares. WITH -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER See response to row 7. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 18,749 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.1% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* PN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 5 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Presidio Management Group IV, L.P. - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. PMG IV is the general partner of USVP IV, SV II and UEP II, and may be deemed to have sole voting power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared voting power with respect to such shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY See response to row 5. OWNED BY -------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 623,125 shares, of which 538,750 are directly owned by WITH USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. PMG IV is the general partner of USVP IV, SV II and UEP II, and may be deemed to have sole dispositive power with respect to such shares, and Bowes, Federman, Krausz and Young, the general partners of PMG IV, may be deemed to have shared dispositive power with respect to such shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER See response to row 7. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 623,125 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.7% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* PN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 6 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) William K. Bowes, Jr. - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 42,747 shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY 623,125 shares, of which 538,750 are directly owned by OWNED BY USVP IV, 65,626 are directly owned by SV II and 18,749 EACH are directly owned by UEP II. Bowes is a general partner REPORTING of PMG IV, the general partner of USVP IV, SV II and UEP PERSON II, and may be deemed to have shared voting power with WITH respect to such shares. -------------------------------------------------------- 7 SOLE DISPOSITIVE POWER 42,747 shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. Bowes is a general partner of PMG IV, the general partner of USVP IV, SV II and UEP II, and may be deemed to have shared dispositive power with respect to such shares. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 665,872 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.9% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 7 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Irwin Federman - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 46,801 shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY 623,125 shares, of which 538,750 are directly owned by OWNED BY USVP IV, 65,626 are directly owned by SV II and 18,749 EACH are directly owned by UEP II. Federman is a general REPORTING partner of PMG IV, the general partner of USVP IV, SV II PERSON and UEP II, and may be deemed to have shared voting WITH power with respect to such shares. -------------------------------------------------------- 7 SOLE DISPOSITIVE POWER 46,801 shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. Federman is a general partner of PMG IV, the general partner of USVP IV, SV II and UEP II, and may be deemed to have shared dispositive power with respect to such shares. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 669,926 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.9% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 8 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Steven M. Krausz - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 10,953 shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY 623,125 shares, of which 538,750 are directly owned by OWNED BY USVP IV, 65,626 are directly owned by SV II and 18,749 EACH are directly owned by UEP II. Krausz is a general REPORTING partner of PMG IV, the general partner of USVP IV, SV II PERSON and UEP II, and may be deemed to have shared voting WITH power with respect to such shares. -------------------------------------------------------- 7 SOLE DISPOSITIVE POWER 10,953 shares. -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. Krausz is a general partner of PMG IV, the general partner of USVP IV, SV II and UEP II, and may be deemed to have shared dispositive power with respect to such shares. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 634,078 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.8% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No. 693282105 Page 9 of 16 Pages - -------------------------------------------------------------------------------- 1 NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Philip M. Young - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION U.S. Citizen - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER 49,980 shares. -------------------------------------------------------- NUMBER OF 6 SHARED VOTING POWER SHARES BENEFICIALLY 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. Young is a general partner of PMG IV, the general partner of USVP IV, SV II and UEP II, and may be deemed to have shared voting power with respect to such shares. OWNED BY -------------------------------------------------------- EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 49,980 shares. WITH -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER 623,125 shares, of which 538,750 are directly owned by USVP IV, 65,626 are directly owned by SV II and 18,749 are directly owned by UEP II. Young is a general partner of PMG IV, the general partner of USVP IV, SV II and UEP II, and may be deemed to have shared dispositive power with respect to such shares. - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 673,105 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* |_| - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.9% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IN - -------------------------------------------------------------------------------- *SEE INSTRUCTION BEFORE FILLING OUT!

Page 10 of 16 This statement amends the statement on Schedule 13G filed by U.S. Venture Partners IV, L.P., Second Ventures II, L.P., USVP Entrepreneur Partners II, L.P., Presidio Management Group IV, L.P., William K. Bowes, Jr., Irwin Federman , Steven M. Krausz and Philip M. Young. The foregoing entities and individuals are collectively referred to as the "Reporting Persons." ITEM 4. OWNERSHIP: The following information with respect to the ownership of the Common Stock of the issuer by the persons filing this Statement is provided as of December 31, 2002: (a) Amount beneficially owned: See Row 9 of cover page for each Reporting Person. (b) Percent of Class: See Row 11 of cover page for each Reporting Person. (c) Number of shares as to which such person has: (i) Sole power to vote or to direct the vote: See Row 5 of cover page for each Reporting Person. (ii) Shared power to vote or to direct the vote: See Row 6 of cover page for each Reporting Person. (iii)Sole power to dispose or to direct the disposition of: See Row 7 of cover page for each Reporting Person. (iv) Shared power to dispose or to direct the disposition of: See Row 8 of cover page for each Reporting Person.

Page 11 of 16 ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS: If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following: Yes [X]

Page 12 of 16 SIGNATURES After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated: February 11, 2003 U.S. Venture Partners IV, L.P. /s/ Michael Maher By Presidio Management Group IV, L.P. ----------------------------------------- Its General Partner Signature Michael Maher Chief Financial Officer/Attorney-In-Fact Second Ventures II, L.P. /s/ Michael Maher By Presidio Management Group IV, L.P. ----------------------------------------- Its General Partner Signature Michael Maher Chief Financial Officer/Attorney-In-Fact USVP Entrepreneur Partners II, L.P. /s/ Michael Maher By Presidio Management Group IV, L.P. ---------------------------------------- Its General Partner Signature Michael Maher Chief Financial Officer/Attorney-In-Fact Presidio Management Group IV, L.P. /s/ Michael Maher A Delaware Limited Partnership ----------------------------------------- Signature Michael Maher Chief Financial Officer/Attorney-In-Fact William K. Bowes, Jr. /s/ Michael Maher ----------------------------------------- Michael Maher Attorney-In-Fact Irwin Federman /s/ Michael Maher ----------------------------------------- Michael Maher Attorney-In-Fact

Page 13 of 16 Steven M. Krausz /s/ Michael Maher ----------------------------------------- Michael Maher Attorney-In-Fact Philip M. Young /s/ Michael Maher ----------------------------------------- Michael Maher Attorney-In-Fact

Page 14 of 16 EXHIBIT INDEX Found on Sequentially Exhibit Numbered Page - ------- ------------- Exhibit A: Agreement of Joint Filing 15 Exhibit B: Reference to Michael P. Maher as Attorney-In-Fact 16

Page 15 of 16 EXHIBIT A Agreement of Joint Filing The Reporting Persons have agreed that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of PDF Solutions, Inc. shall be filed on behalf of each of the Reporting Persons. Note that copies of the applicable agreement are already on file with the appropriate agencies.

Page 16 of 16 EXHIBIT B REFERENCE TO MICHAEL MAHER AS ATTORNEY-IN-FACT Michael P. Maher has signed the enclosed documents as Attorney-In-Fact. Note that copies of the applicable Powers of Attorney are already on file with the appropriate agencies.