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                                                                   EXHIBIT 10.29

                                  DOVEBID, INC.
                                  ------------

                           AMENDMENT TO CONVERTIBLE
                          SUBORDINATED PROMISSORY NOTE

     This Amendment is entered into as of May 22, 2001, by and between David S.
Gronik ("Payee") and DoveBid, Inc., a Delaware corporation (the "Company"). This
Amendment amends the terms and conditions of that certain Convertible
Subordinated Promissory Note issued by the Company to Payee on March 2, 2000 in
the principal amount of $1,425,000 (the "Note").

     Whereas, Payee and the Company desire to amend the Note on the terms and
conditions set forth below;

     Now, therefore, in consideration of the foregoing and for other good and
valuable consideration (receipt and sufficiency of which is mutually
acknowledged), the parties agree as follows:

     1. Extension of Term. The second sentence of the Note is hereby amended to
read as follows.

        "The Optional Convertible Debt (as defined below) will be due and
        payable in lawful money of the United States in full on March 2, 2004,
        unless the Optional Convertible Debt shall have been previously paid by
        the Company or converted pursuant to Section 2 below, in which case the
        portion of the Optional Convertible Debt that was converted shall be
        satisfied in full by virtue of such conversion and the issuance and
        delivery of fully paid and non-assessable shares of Conversion Stock to
        the holder of this Note as set forth in Section 2 below. The principal
        and accrued interest that does not constitute Optional Convertible Debt
        will be due and payable as follows: principal in the amount of $250,000
        will be due and payable in lawful money of the United States in full on
        March 2, 2003 and principal in the amount of $462,500 and all accrued
        but unpaid interest will be due and payable in lawful money of the
        United States in full on March 2, 2004 (the "Maturity Date") in each
        case unless such principal and/or accrued interest shall have been
        previously paid by the Company or converted pursuant to Section 2 below,
        in which case the portion of the principal that was converted and all
        accrued but unpaid interest thereon shall be satisfied in full by virtue
        of such conversion and the issuance and delivery of fully paid and
        non-assessable shares of Conversion Stock to the holder of this Note as
        set forth in Section 2 below. Notwithstanding the foregoing, the
        Optional Convertible Debt shall be immediately due and payable in lawful
        money of the United States in full upon the sale, conveyance, lease,
        transfer or other disposition of substantially all of the

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        assets of the Company to an acquirer who is not a reporting company
        under Section 13 or 15 of the Securities Exchange Act of 1934, as
        amended ("a Private Company"), or of a majority of the outstanding
        voting securities of the Company to a Private Company, in a single
        transaction or in a series of related transactions which occurs after
        March 2, 2002."

     2. Definitions.
        -----------

        2.1 Definition of Mandatory Convertible Debt. A new definition is hereby
added to the Note as Section 1.7 to read as follows: " `Mandatory Convertible
Debt" shall mean all of the principal amount of this Note and all of the accrued
but unpaid interest on this Note, as reduced by (i) any prepayments made by the
Company as permitted in Section 4 hereof and (ii) any conversion pursuant to
Section 2.2 of this Note."

        2.2 Definition of Optional Convertible Debt. A new definition is hereby
added to the Note as Section 1.8 to read as follows: " `Optional Convertible
Debt" shall mean $712,500 of the principal amount of this Note and all of the
accrued but unpaid interest on such principal, as reduced by any prepayments
made by the Company as permitted in Section 4 hereof."

        2.3 Definition of Conversion Stock. Section 1.2 of the Note is hereby
amended to read as follows: " `Conversion Stock' shall mean shares of Common
Stock of the Company, with respect to conversion of the Optional Convertible
Debt, and shall mean Common Stock of the Company of the same class of common
stock that is registered by the Company pursuant to an Initial Public Offering,
with respect to conversion of the Mandatory Convertible Debt. With respect to
Optional Convertible Debt, if the outstanding Common Stock of the Company shall
hereafter be changed through a reorganization or recapitalization into shares of
a different series or class of the Company's capital stock, the Conversion Stock
shall thereafter mean the shares into which the Common Stock was changed."

        2.4 Definition of Conversion Price. Section 1.3 of the Note is hereby
amended to read as follows: " The `Conversion Price' for Optional Convertible
Debt shall mean $8.01 per share of Conversion Stock, as appropriately adjusted
to reflect the effect of stock splits and combinations, stock dividends,
recapitalizations and reorganizations of or on the Conversion Stock after the
date hereof. For Mandatory Convertible Debt, the `Conversion Price' shall mean
the price per share that is the exact middle of the price range stated in the
Company's final amended registration statement on Form S-1, Form SB-1, Form SB-2
or a similar successor form pertaining to an Initial Public Offering that closes
on before the Maturity Date. No conversion shall occur and there is therefore no
Conversion Price with respect to an Initial Public Offering that closes after
the Maturity Date."

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     3.  Conversion. Section 2 of the Note is hereby amended to read as follows:
         ----------

               "2.1 Mandatory Conversion. This Note and all of the outstanding
         Mandatory Convertible Debt shall be converted into Conversion Stock at
         the Conversion Price immediately prior to the first closing of an
         Initial Public Offering before the Maturity Date. For informational
         purposes, the Company shall provide the Noteholder with written notice
         (at the most recent address for the Noteholder provided to the Company
         by the Noteholder in writing) (i) within seven days after it files with
         the Securities and Exchange Commission any registration statement on
         Form S-1, Form SB-1 or Form SB-2 (or any similar or successor form) for
         an Initial Public Offering, and (ii) reasonably promptly following the
         closing of an Initial Public Offering. Conversion as described in this
         Section 2.1 shall occur only upon the closing of an Initial Public
         Offering, provided that (i) upon the closing of an Initial Public
         Offering, the conversion shall be deemed to have occurred immediately
         prior to the first closing of such Initial Public Offering, and (ii) as
         a condition precedent or condition subsequent to conversion (the
         election between which type of condition shall be the Company's sole
         election in the Company's sole discretion), the Noteholder must
         surrender this Note for conversion at the principal office of the
         Company. Incident to any conversion, the Conversion Stock will have
         those rights and privileges, and be subject to those restrictions, of
         the shares of Common Stock as set forth in the Company's Certificate of
         Incorporation, and the Noteholder will receive the rights and be
         subject to the obligations applicable to the purchasers of Common
         Stock, provided that the sale restriction specified in Section 2.6
         below shall apply to the Conversion Stock. This Note shall not be
         convertible pursuant to this Section 2.1 and shall not be converted
         into Conversion Stock under this Section 2.1 if there is not an Initial
         Public Offering on or before the Maturity Date.

               2.2  Optional Conversion.
                    -------------------

               2.2.1 If not previously converted pursuant to Section 2.1 above,
         all of the outstanding Optional Convertible Debt may be converted, at
         any time prior to the Maturity Date, into Conversion Stock at the
         Conversion Price in the sole discretion of the Company. To elect to
         convert the Optional Convertible Debt, the Company shall send written
         notice of its election to the Noteholder prior to the Maturity Date.
         Noteholder will thereafter deliver the original Note to the Company at
         the Company's principal office for reissuance to reflect the conversion
         of the Optional Convertible Debt. Incident to any conversion, the
         Conversion Stock will have those rights and privileges, and be subject
         to those restrictions, of the shares of Conversion Stock as set forth
         in the Company's Certificate of Incorporation, and the Noteholder will
         receive

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          the rights and be subject to the obligations applicable to the
          purchasers of Conversion Stock, provided that the sale restriction
          specified in Section 2.6 below shall apply to the Conversion Stock.

                    2.2.2 In the event of any conversion pursuant to this
          Section 2.2 prior to March 2, 2004, the Company shall pay to
          Noteholder, in cash, an amount equal to the lesser of (a) the United
          States state and federal capital gains tax imposed on Noteholder as a
          result of the receipt of such Conversion Stock or (b) an amount equal
          to the outstanding principal and accrued but unpaid interest then
          represented by this Note (the "Tax Payment"). The amount paid by the
          Company shall be offset first against any accrued but unpaid interest
          due hereunder and then against the outstanding principal amount of
          this Note. Upon conversion of this Note pursuant to this Section 2.2
          and calculation of Noteholder's capital gains tax therefor, Noteholder
          will give the Company at least 30 days prior written notice thereof to
          permit the Company to verify the capital gains calculation made by
          Noteholder and will deliver such information to the Company as may be
          necessary to conduct such verification. The Tax Payment shall be made
          by the Company after the 30-day verification period but need not be
          paid earlier than 10 days prior to the time Noteholder's capital gains
          tax must be paid in connection with conversion of this Note as
          provided in this Section 2.2 above.

                    2.2.3 If the Company fails to deliver the written notice of
          conversion provided for in Section 2.2.1 prior to the Maturity Date,
          the conversion right of the Company that is set forth in this Section
          2.2 shall terminate on the Maturity Date.

               2.3  No Fractional Shares. No fractional shares will be issued on
          conversion of this Note. If on any conversion of this Note a fraction
          of a share results, the Company will pay the cash value of that
          fractional share, calculated on the basis of the applicable Conversion
          Price.

               2.4  Reservation of Stock. Prior to any conversion of this Note
          pursuant to this Section 2 above, the Company will take such corporate
          action and obtain such government consents and approvals as may, in
          the reasonable opinion of its counsel, be necessary to authorize the
          issuance of a sufficient number of shares of Conversion Stock into
          which this Note is to convert.

               2.5  Fully Paid Shares; Certificates. All shares of Conversion
          Stock issued upon the conversion of this Note shall be validly issued,
          fully paid and non-assessable. The certificates representing the
          shares of Conversion Stock issued upon conversion hereof shall be
          delivered to the holder against surrender of this Note. The holder, by
          accepting this Note,

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        undertakes and agrees to accept such shares of Conversion Stock in full
        satisfaction of the Optional Convertible Debt or of the Mandatory
        Convertible Debt, as the case may be, that is outstanding as of the
        effective date of conversion in accordance with the terms of this Note.
        Anything to the contrary in this Note notwithstanding, the Company's
        obligation to issue shares of Conversion Stock to any holder of this
        Note is expressly conditioned upon compliance of such issuance with
        applicable federal and state securities laws without registration or
        other qualification thereunder.

               2.6 Restriction on Sale. Upon and following any conversion
         pursuant to this Section 2, no holder of any Conversion Stock shall
         effect any sale or distribution of any of the Conversion Stock (which
         shall include any and all voting securities received by such holder as
         or in connection with a stock dividend, stock split or other
         recapitalization or similar distribution on or in respect of the
         Conversion Stock) or any of the Company's other equity securities, or
         of any securities convertible into or exchangeable for such securities,
         during the period beginning on the closing of the Initial Public
         Offering and ending 180 days after such closing. The certificate(s)
         representing the shares of Conversion Stock issued upon the conversion
         of this Note shall be legended to reflect such restriction on sale.

               2.7 No Rights or Liabilities as Shareholder. This Note does not
         by itself entitle the Noteholder to any voting rights or other rights
         as a shareholder of the Company. In the absence of conversion of this
         Note, no provisions of this Note, and no enumeration herein of the
         rights or privileges of the holder shall cause such holder to be a
         shareholder of the Company for any purpose by virtue hereof.

               2.8 No Other Conversion. The conversion provisions set forth in
         this Section 2 constitute the sole methods by which this Note will
         convert."

     4.  Effect of Prepayments. There is hereby added an additional sentence at
the end of Section 4 of the Note to read as follows: "In the event of any
partial prepayment of the Note, the amount prepaid shall be credited towards the
Optional Convertible Debt and/or any portion of the Mandatory Convertible Debt
that does not constitute Optional Conversion Debt, as specified at the time of
such prepayment by the Company, in its sole discretion, until the Note is repaid
in full."

     5.  Effect of Amendment. This Amendment will be effective as of the date
first set forth above, upon execution of this Amendment by the Company and
Payee. This Amendment may be executed in any number of counterparts, each of
which shall be deemed an original and all of which, taken together, will
constitute one and the same Amendment. Except as expressly provided above, the
terms and conditions of the Note remain in full force and effect, unmodified,

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as of the date hereof. None of the rights of Payee under the Note or this
Amendment shall be terminated, waived, or otherwise adversely affected by any
termination by Payee or the Company of Payee's employment with the Company.

        In Witness Whereof, Payee and the Company have executed this Amendment
to Convertible Subordinated Promissory Note, in the case of the Company by a
person duly authorized to do so.

THE COMPANY: DOVEBID, INC.                   PAYEE: DAVID S. GRONIK


By:     /s/ Anthony Capobianco                   /s/ David S. Gronik
    ----------------------------------       ----------------------------------
                                             (Signature of Payee)
Title:  VP and General Counsel
       -------------------------------

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