<PAGE>

                                                                   EXHIBIT 10.42

NEITHER THIS NOTE NOR ANY SECURITIES WHICH MAY BE ISSUED UPON CONVERSION HEREOF
HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR REGISTERED
OR OTHERWISE QUALIFIED UNDER ANY STATE SECURITIES LAW.  NEITHER THIS NOTE NOR
ANY SUCH SECURITIES MAY BE SOLD OR OFFERED FOR SALE IN THE ABSENCE OF AN
EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT AND REGISTRATION OR OTHER
QUALIFICATION UNDER ANY APPLICABLE STATE SECURITIES LAWS, OR AN OPINION OF
COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION OR OTHER
QUALIFICATION IS NOT REQUIRED.


                                 DOVEBID, INC.

                   CONVERTIBLE SUBORDINATED PROMISSORY NOTE

$5,000,000                                                         June 15, 2000

     DoveBid, Inc., a Delaware corporation (the "Company"), with offices at 1241
East Hillsdale Blvd., Foster City, CA 94404, for value received, promises to pay
to the order of Robinc Holding B.V. ("Payee"), or Payee's permitted assigns (the
"Noteholder") at such address as the Noteholder may designate, Five Million
Dollars and No Cents ($5,000,000), plus simple interest thereon calculated from
the date hereof until paid at 6.53% per annum.  Principal and accrued interest
will be due and payable in lawful money of the United States in full on the
three year anniversary of the date of this Note (the "Maturity Date"), unless
this Note shall have been previously converted pursuant to Section 2 below, in
which case all outstanding principal under this Note and all accrued 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.  Payments by the Company
shall be applied first to any and all accrued interest through the payment date
and second to the principal remaining due hereunder.

     The following is a statement of the rights of the holder of this Note and
the conditions to which this Note is subject, and to which the holder hereof, by
the acceptance of this Note, agrees:

     1.   Definitions.  As used in this Note, the following terms, unless the
          -----------
context otherwise requires, have the following meanings:

          1.1  "Company" includes any corporation or other entity which succeeds
to or assume the obligations of the Company under this Note.

                                      -1-

<PAGE>

          1.2  "Conversion Stock" shall mean shares of Common Stock of the
Company of the same class of common stock that is registered by the Company
pursuant to an Initial Public Offering.

          1.3  "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 or 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.

          1.4  "Noteholder," "holder," or similar terms, when the context refers
to a holder of this Note, shall mean any person who shall at the time be the
registered holder of this Note.

          1.5  "Initial Public Offering" shall mean the closing of a sale of
Common Stock pursuant to a registration statement on Form S-1, Form SB-1 or SB-2
(or any similar or successor form) filed under the Securities Act, for an
underwritten initial public offering.

          1.6  "Securities Act" shall mean the United States Securities Act of
1993, as amended.

          1.7  "Subordination Agreement" shall mean the Subordination Agreement
attached hereto as Annex A and incorporated by reference herein.
                   -------

     2.   Conversion.
          ----------

          2.1  Mandatory Conversion.  This Note and all of the outstanding
               --------------------
principal and accrued and unpaid interest on and under this Note 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 Noteholder with written notice
(at the most recent address for Noteholder provided to the Company by Noteholder
in writing) (i) within seven days after it files with the United States
Securities and Exchange Commission (the "SEC") 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 at the
Company's sole election in the Company's sole discretion), 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 Noteholder will
receive the

                                      -2-

<PAGE>

rights and be subject to the obligations applicable to the purchasers of Common
Stock, provided that the sale restriction specified in Section 5.4 below shall
apply to the Conversion Stock. This Note shall not be convertible and shall not
be converted into Conversion Stock if there is not an Initial Public Offering on
or before the Maturity Date.

          2.2  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.

          2.3  Reservation of Stock.  Prior to any conversion of this Note
               --------------------
pursuant to Section 2.1 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 pursuant to
Section 2.1 above.

          2.4  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, undertakes and agrees to
accept such shares of Conversion Stock in full satisfaction of the outstanding
principal and accrued interest thereon 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.

          2.5  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.

          2.6  No Other Conversion.  The conversion described in this Section 2
               -------------------
shall constitute the sole methods by which this Note will convert.

     3.   Subordination.  This Note and the indebtedness evidenced by this Note
          -------------
are subordinated to the prior payment in full of all or substantially all other
indebtedness of the Company pursuant to the terms of a Subordination Agreement
in the form attached hereto as Annex A and incorporated herein by reference.
                               -------

     4.   Prepayment.  This Note may be prepaid, in its entirety (including the
          ----------
principal sum and interest accrued to the date of payment) without penalty or
premium at any time; provided that prepayment cannot take place after the
Company has filed with the SEC a registration statement on Form S-1, Form SB-1
or Form SB-2 (or any similar

                                      -3-

<PAGE>

or successor form) for an Initial Public Offering and for so long as any such
registration statement remains pending.

     5.   Restrictions on Transfers.
          -------------------------

          5.1  No Transfers Unless Registered or Exempt.  Noteholder understands
               ----------------------------------------
that Noteholder may not transfer any shares of Conversion Stock unless such
shares are registered under the Securities Act and qualified under applicable
state securities laws or unless, in the opinion of counsel to the Company,
exemptions from such registration and qualification requirements are available.
Noteholder acknowledges that the Company's registration statement on Form S-1,
that was previously filed with the SEC on March 10, 2000, has been withdrawn
prior to becoming effective and that the shares of Conversion Stock issuable
upon conversion of this Note will not be registered under the Securities Act.
Noteholder further acknowledges that it will have no rights under Section 11 of
the Securities Act with respect to the issuance of the Conversion Stock upon
conversion of this Note.  Noteholder understands that only the Company may file
a registration statement with the SEC and that the Company is under no
obligation to do so with respect to the Conversion Stock. Noteholder has also
been advised that exemptions from registration and qualification may not be
available or may not permit Noteholder to transfer all or any of the Conversion
Stock in the amounts or at the times proposed by Noteholder.

          5.2  Rule 144.  In addition, Noteholder has been advised that SEC Rule
               --------
144 promulgated under the Securities Act, which permits certain limited sales of
unregistered securities, is not presently available with respect to the
Conversion Stock and, in any event, requires that the Conversion Stock be held
(or deemed held pursuant to Rule 144(d)(3)) for a minimum of one (1) year, and
in certain cases two (2) years, after they have been purchased and paid for
                                                               ------------
(within the meaning of Rule 144), before they may be resold under Rule 144.
Noteholder understands that Rule 144 may indefinitely restrict transfer of the
Conversion Stock so long as Noteholder becomes and remains an "affiliate" of the
Company or if "current public information" about the Company (as defined in Rule
144) is not publicly available.

          5.3  Disposition of Conversion Stock.  Noteholder hereby agrees that
               -------------------------------
Noteholder will make no disposition of the Conversion Stock (other than as
permitted by this Agreement) unless and until: (a) Noteholder has notified the
Company of the proposed disposition and provided a written summary of the terms
and conditions of the proposed disposition; (b) Noteholder has complied with all
requirements of this Note applicable to the disposition of the Conversion Stock
(including the restrictions on transfer); and (c) Noteholder has provided the
Company with written assurances, in form and substance satisfactory to counsel
for the Company, that (i) the proposed disposition does not require registration
of the Conversion Stock under the Securities Act or applicable state securities
laws, or (ii) all appropriate actions necessary for compliance with the
registration requirements of the Securities Act or of any exemption from
registration available under the Securities Act (including Rule 144) and
applicable state securities laws has been taken.

                                      -4-

<PAGE>

          5.4  Restriction on Transfer and Sale.  Noteholder shall not transfer,
               --------------------------------
assign, grant a lien or security interest in, pledge, hypothecate, encumber or
otherwise dispose of any of the Conversion Stock, except as permitted by this
Agreement.  Upon and following any conversion of this Note, 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 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 restrictions on sale.

          5.5  Legends.  Noteholder understands and agrees that the Company will
               -------
place appropriate legends on any stock certificate(s) evidencing the Conversion
Stock that may be required by state or federal securities laws, the Company's of
Incorporation or Bylaws, this Note any other agreement.  Noteholder agrees that,
to ensure compliance with the restrictions imposed by this Note, the Company may
issue appropriate "stop-transfer" instructions to its transfer agent, if any,
and if the Company transfers its own securities, it may make appropriate
notations to the same effect in its own records.  The Company will not be
required (i) to transfer on its books any Conversion Stock that have been sold
or otherwise transferred in violation of any of the provisions of this Note, or
(ii) to treat as owner of such Conversion Stock, or to accord the right to vote
or pay dividends to any purchaser or other transferee to whom such Conversion
Stock have been so transferred.

          5.6  Disclosure.  The Company agrees, for a period of two years
               ----------
following the date of this Agreement, to use reasonable commercial efforts to:

               (a)  make and keep material public information available within
the meaning of Rule 144(c) of the Securities Act at all times after ninety (90)
days after the closing of the Initial Public Offering; and

               (b)  file with the SEC in a timely manner all reports and other
material documents required of the Company under the Securities Act and the
United States Securities Exchange Act of 1934, as amended (the "Exchange Act").

     6.   Usury Savings Clause.  The Company and the Noteholder intend to comply
          --------------------
at all times with applicable usury laws.  If at any time such laws would render
usurious any amounts due under this Note under applicable law, then it is the
Company's and the Noteholder's express intention that the Company not be
required to pay interest on this Note at a rate in excess of the maximum lawful
rate, that the provisions of this Section 6 shall control over all other
provisions of this Note which may be in apparent conflict hereunder, that such
excess amount shall be immediately credited to the principal balance of this
Note (or, if this Note has been fully paid, refunded by the Noteholder to the
Company), and the provisions hereof shall immediately be reformed and the
amounts

                                      -5-

<PAGE>

thereafter decreased, so as to comply with the then applicable usury law, but so
as to permit the recovery of the fullest amount otherwise due under this Note.

     7.   General Provisions.
          ------------------

          7.1  Notices.  All notices and other communications required or
               -------
permitted hereunder shall be effective upon receipt (or refusal of receipt) and
shall be in writing and delivered by depositing the same in United States mail,
addressed to the party to be notified, postage prepaid and registered or
certified with return receipt requested, by delivering the same in person to
such party or to an officer or agent of such party (or in the case of the Payee
by facsimile), as follows:

               (i)  If mailed or delivered to the Company, to each of the
following, using two separate mailings or deliveries:

               DoveBid, Inc.
               1241 East Hillsdale Blvd.
               Foster City, CA 94404
               Attn: Cory Ravid, Chief Financial Officer

               DoveBid, Inc.
               1241 East Hillsdale Blvd.
               Foster City, CA 94404
               Attn: Anthony Capobianco, General Counsel

               (ii) If mailed, delivered or faxed to the Payee, addressed or
faxed to it at the following address or fax number:

               Robinc Holding B.V.
               1411 DD Naarden, Gooimeer 6
               The Netherlands
               Fax: _______________

               with a copy to:

               Stibbe Simont Monahan Duhot
               Stibbetoren
               2001 Strawinskylaan
               1077 ZZ Amsterdam
               The Netherlands
               Attn: Jurjen de Korte
               Fax: 011-31-70-546 0123

               or to such other address (or in the case of the Payee, the fax
number) as any party hereto shall specify in writing to the other parties hereto
pursuant to this Section 7.1 from time to time. Such notice shall be effective
only upon actual receipt.

                                      -6-

<PAGE>

          7.2  Severability; Headings.  In case any provision of this Note shall
               ----------------------
be invalid, illegal or unenforceable, the validity, legality and enforceability
of the remaining provisions shall not in any way be affected or impaired
thereby, unless to do so would deprive the Noteholder or the Company of a
substantial part of its bargain.  All headings used herein are used for
convenience only and shall not be used to construe or interpret this Note.

          7.3  Noteholder Representations and Status.  By accepting this Note,
               -------------------------------------
the Payee and any other Noteholder each acknowledges, represents and warrants
that (i) this Note is being acquired for investment, solely for its own account
and not as a nominee for any other person or entity, and that it will not offer,
sell or otherwise dispose of this Note except as expressly permitted by this
Note and under circumstances which will not result in a violation of the
Securities Act and (ii) it is an "accredited investor" with the meaning of Rule
501(a) of Regulation D promulgated under the Securities Act.

          7.4  Assignment.  Neither this Note nor any right or obligation
               ----------
hereunder may be assigned or delegated by Payee without the prior written
consent of the Company, except to Robert Bouland.  Neither this Note nor any
right or obligation hereunder may be assigned or delegated by the Company
without the prior written consent of Payee, except pursuant to a merger in which
the Company is a party, or pursuant to a sale or other transfer of substantially
all of the assets of the Company.  Any purported assignment in violation of this
paragraph shall be void.

          7.5  Amendment; Waiver.  Any provision of this Note may be amended or
               -----------------
modified only by a writing signed by both the Company and Noteholder.
Compliance with any provision of this Note may be waived only by a writing
signed by the party against which enforcement of the change, waiver, discharge
or termination is sought.

          7.6  Governing Law.  This Note shall be construed and enforced in
               -------------
accordance with, and governed by, the internal laws of the State of California,
excluding that body of law applicable to conflicts of laws.



             [The rest of this page is intentionally left blank.]

                                      -7-

<PAGE>

          IN WITNESS WHEREOF, each party has caused this Note to be executed as
of the date first set forth above.

                              DOVEBID, INC.


                              By:       /s/ Anthony Capobianco
                                 -------------------------------------------
                              Name:  Anthony Capobianco
                              Title: Vice President and General Counsel


Acknowledged and Agreed to
by Robinc Holding B.V.:


By:  /s/ Robert Bouland
   ------------------------
Name:  Robert Bouland
Title: Director

                                      -8-