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                                                                EXHIBIT 10(d)(3)


                          CONVERTIBLE PROMISSORY NOTE

$500,000.00                      Dallas, Texas                 September 6, 1996

       1.     PRINCIPAL.  For value received, ErgoBilt, Inc., a Texas
corporation ("Maker"), hereby promises to pay to Summit Partners Management Co.
("Payee") or order, in accordance with the terms of this promissory note
("Note"), at such place as Payee may from time to time in writing designate,
the sum of Five Hundred Thousand and No/100 Dollars ($500,000.00), together
with interest at the "Interest Rate" as defined below, on the terms and
conditions set forth herein.

       2.     INTEREST RATE.  Interest shall accrue on the unpaid principal
balance due under this Note at an annual percentage rate (the "Interest Rate")
equal to eight percent (8%) based on a three hundred sixty (360) day year and
actual days elapsed.  Interest shall accrue from the date of this Note until
paid in full.

       3.     PAYMENT.

              3.1.   Maturity Date.  Subject to the mandatory prepayment
obligation described in Paragraph 3.3 below, the entire principal balance and
all accrued unpaid interest shall be due and payable one (1) year from the date
of this Note (the "Maturity Date").  All payments shall be made in currency of
the United States.

              3.2.   Voluntary Prepayment.  Maker may prepay all or any part of
the unpaid principal balance at any time without penalty or premium.

              3.3.   Mandatory Prepayment.  Prior to the Maturity Date, Maker
intends to complete an initial public offering of Maker's common stock (the
"IPO").  If the IPO closes at any time prior to the Maturity Date, then Maker
shall repay to Payee, concurrently with the closing of the IPO, the sum of Two
Hundred Fifty Thousand and No/100 Dollars ($250,000.00) in principal (or
one-half of the unpaid principal balance due under the Note, whichever is
less), plus all accrued and unpaid interest on this Note.  The remaining
principal balance under this Note shall be converted into common stock of the
Maker pursuant to Paragraph 4.1 below.

              3.4.   Security.  This Note is secured by the Investment and
Security Agreement dated as of the date hereof (the "Security Agreement") among
Maker, Gerald McMillan and Payee, and Payee shall be entitled to the benefit
thereof.

       4.     CONVERSION.

              4.1.   Conversion.  Subject to the terms and conditions of this
Paragraph 4, upon Mandatory Prepayment, the unpaid principal balance remaining
due under this Note after such Mandatory Prepayment, contemporaneously
therewith, shall be automatically converted to shares of the Common Stock,
$0.10 par value, of Maker ("Maker's Common Stock") at a conversion rate
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equal to such principal amount divided by a price per share equal to the "IPOP"
(as defined herein).  The term "IPOP" shall mean the "Price to the Public" of
one share of Maker's Common Stock as set forth on the cover page of the final
prospectus for the IPO.

              4.2.   Delivery of Shares; Reduction in Principal Balance.  Upon
Conversion pursuant to Section 4.1, Maker shall issue and deliver to Payee or
its designated affiliates certificates representing the shares of Maker's
Common Stock, registered in Payee's or its designated affiliate's name(s).
Upon issuance of the shares, the principal balance due under this Note shall be
deemed automatically reduced by that amount of principal converted into shares
of Maker's Common Stock.

              4.3.   Anti-Dilution Provisions and Notice.

                     (a)    Notice.  In case:

                            (i)    Maker declares a dividend or other
distribution on Maker's Common Stock payable otherwise than in cash out of
retained earnings; or

                            (ii)   Maker authorizes the issuance to the holders
of Maker's Common Stock of rights, options or warrants entitling them to
subscribe for or purchase any shares of capital stock of any class or any other
subscription rights, options or warrants; or

                            (iii)  Of any reclassification of the capital stock
of the corporation (other than a subdivision or combination of outstanding
shares of Maker's Common Stock), or of any consolidation or merger to which
Maker is a party, or of the sale, transfer or other disposition of all or
substantially all of the assets of Maker; or

                            (iv)   Of the voluntary or involuntary liquidation,
dissolution or winding up of Maker;

                     then Maker shall file with the transfer agent for the 
shares of Maker's Common Stock and shall cause to be mailed to Payee, at least
twenty (20) days prior to the applicable record or effective date hereinafter
specified, a notice stating (x) the date as of which the holders of record of
Maker's Common Stock to be entitled to such dividend, distribution, rights or
warrants are to be determined, or (y) the date on which such reclassification,
consolidation, merger, sale, transfer disposition, liquidation, dissolution or
winding up is expected to become effective, and the date as of which it is
expected that the holders of record of Maker's Common Stock shall be entitled
to exchange their shares for securities, cash or other property deliverable
upon such reclassification, consolidation, merger, sale, transfer, disposition,
liquidation, dissolution or winding up, and if applicable, the vote on any
action authorizing such.

                     (b)    Stock Split.  In the event Maker shall at any time
split in a greater or  combine in a lesser number of shares the outstanding
shares of Maker's Common Stock, the number of shares of Maker's Common Stock
issuable upon conversion shall be increased proportionately





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in case of subdivision or decreased in the case of a combination, effective in
either case at the close of business on the date when such subdivision or
combination becomes effective.

                     (c)    Recapitalization or Merger.  In the event that
Maker shall be recapitalized, consolidated with or merged into any other
corporation, or shall sell or convey to any other corporation all or
substantially all of its property as an entirety, provision shall be made as
part of the terms of such recapitalization, consolidation, merger, sale or
conveyance so that any holder of Maker's Common Stock may thereafter receive in
lieu of Maker's Common Stock otherwise issuable to him upon conversion of his
shares the same kind and amount of securities or assets as may be distributable
upon such recapitalization, consolidation, merger, sale or conveyance with
respect to Maker's Common Stock.

                     (d)    Dividend.  In the event that Maker shall at any
time pay to the holders of Maker's Common Stock a dividend in Maker's Common
Stock, the number of shares of Maker's Common Stock issuable upon Payee's
exercise of its Conversion Rights shall be proportionately increased, effective
at the close of business on the payment date for determination of such
dividend.

              4.4.   Adequate Shares.  Maker shall at all times reserve and
keep available, free from preemptive rights, out of the authorized but unissued
shares of Maker's Common Stock, for the purpose of issuance upon conversion, a
sufficient number of shares of Maker's Common Stock potentially deliverable
upon Payee's exercise of its Conversion Rights.

              4.5.   Taxes.  Maker shall not be required to pay any tax which
may be payable in respect of the original issuance or payable in respect of any
transfer involved in the issuance and delivery of shares of Maker's Common
Stock in a name other than that in which the shares so converted were
registered, and no such issuance or delivery shall be made unless and until the
person requesting such issuance has paid to Maker the amount of any such tax or
has established to the satisfaction of Maker that such tax has been paid.

              4.6.   Limitations.  Shares of Maker's Common Stock issuable upon
conversion shall include only shares of the class designated as Common Stock as
of the date of this Note or shares of Maker of any classes or series resulting
from any reclassification or reclassifications thereof and which have no
preference or priority in the payment of dividends or in the distribution of
assets in the event of any voluntary or involuntary liquidation, dissolution or
winding up of the corporation and which are not subject to redemption by Maker,
provided that if, at any time there shall be more than one such resulting class
or series, the shares of each such class and series then so issuable shall be
substantially in the proportion which the total number of shares of such class
and series resulting from all such reclassifications bears to the total number
of shares of all such classes and series resulting from all such
reclassifications.

              4.7.   Restrictions on Transferability.  All shares of Maker's
Common Stock issued to Payee in satisfaction of Payee's conversion rights shall
be validly issued, fully paid and nonassessable.  No fractional shares shall be
issued.  Payee acknowledges and understands that the





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certificates of Maker's Common Stock issued to it upon exercise of its
Conversion Rights will bear a restrictive legend in substantially the following
form:

                     "The shares represented by this certificate have not been
                     registered under the Securities Act of 1933, as amended,
                     and may not be offered, sold or otherwise transferred,
                     pledged or hypothecated unless and until such shares are
                     registered under such Act or an opinion of counsel
                     satisfactory to Company is obtained to the effect that
                     such registration is not required."

       5.     ALLOCATION OF PAYMENTS.  Any amounts, when paid against this
Note, shall be credited first to any reasonable costs or expenses incurred by
Payee to collect on this Note, then to the interest then due, and then to
unpaid principal.  Interest shall cease to accrue upon any principal paid.

       6.     EVENTS OF DEFAULT AND REMEDIES

              6.1    An "Event of Default" shall exist if any one or more of
the following events (herein collectively called "Events of Default") occurs
and is continuing:

                     (a)    Maker shall fail to pay when due any principal of
or interest on this Note;

                     (b)    Maker shall fail to pay when due any fee, expense
or other payment required hereunder after five (5) days' prior written notice
from Payee of such delinquency;

                     (c)    any representation or warranty made in this Note,
or any of the other documents executed in connection herewith or relating
hereto, including, without limitation, the Warrant and Common Stock
Subscription Agreement dated as of the date hereof between Maker and Payee and
the Security Agreement (the "Loan Documents"), or in any certificate or
statement furnished or made to Payee pursuant hereto or thereto or in
connection herewith or therewith shall prove to be untrue or inaccurate in any
material respect as of the date on which such representation or warranty is
made;

                     (d)    default shall occur in the performance of any of
the covenants or agreements of Maker contained herein, or in any of the other
Loan Documents;

                     (e)    default shall occur in the payment of any
indebtedness of Maker or default shall occur in respect of any note, loan
agreement or credit agreement relating to any such indebtedness and such
default shall continue for more than the period of grace, if any, specified
therein; or any such indebtedness shall become due before its stated maturity
by acceleration of the maturity thereof or shall become due by its terms and
shall not be promptly paid or extended;





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                     (f)    any of the Loan Documents shall cease to be legal,
valid, binding agreements enforceable against any party executing the same in
accordance with the respective terms thereof or shall in any way be terminated
or become or be declared ineffective or inoperative or shall in any way
whatsoever cease to give or provide the respective liens, security interest,
rights, titles, interest, remedies, powers or privileges intended to be created
thereby;

                     (g)    Company shall (i) apply for or consent to the
appointment of a receiver, trustee, custodian, intervenor or liquidator of
itself or of all or a substantial part of its assets, (ii) file a voluntary
petition in bankruptcy or admit in writing that it is unable to pay its debts
as they become due, (iii) make a general assignment for the benefit of
creditors, (iv) file a petition or answer seeking reorganization of an
arrangement with creditors or to take advantage of any bankruptcy or insolvency
laws, (v) file an answer admitting the material allegations of, or consent to,
or default in answering, a petition filed against it in any bankruptcy,
reorganization or insolvency proceeding, or (vi) take corporate action for the
purpose of electing any of the foregoing;

                     (h)    an involuntary petition or complaint shall be filed
against Maker seeking bankruptcy or reorganization of Maker, or the appointment
of a receiver, custodian, trustee, intervenor or liquidator of Maker, or all or
substantially all of its assets, or an order, order for relief, judgment or
decree shall be entered by any court of competent jurisdiction or other
competent authority approving a petition or complaint seeking reorganization of
Maker or appointment of a receiver, custodian, trustee, intervenor or
liquidator of Maker, or of all or substantially all of its assets;

                     (i)    any final judgment(s) for the payment of money in
excess of the sum of $25,000.00 in the aggregate shall be rendered against
Maker and such judgment or judgments shall not be satisfied or discharged at
least ten (10) days prior to the date on which any of its assets could be
lawfully sold to satisfy such judgment; or

                     (j)    Maker sells, leases or otherwise disposes of all or
substantially all of the assets of Maker, whether in one transaction or through
a series of transactions, or merges with or consolidates into any other person.

              6.2    Remedies Upon Event of Default.  If an Event of Default
occurs and is continuing, then Payee shall exercise any one or more of the
following rights and remedies, and any other remedies provided in any of the
Loan Documents, as Payee may deem necessary or appropriate:  (i) declare the
principal of, and all interest then accrued on, this Note and any other
liabilities hereunder to be forthwith due and payable, whereupon the same shall
forthwith become due and payable without presentment, demand, protest, notice
of default, notice of acceleration or of intention to accelerate or other
notice of any kind, all of which Maker hereby expressly waives, anything
contained herein or in the Loan Documents to the contrary notwithstanding, (ii)
reduce any claim to judgment, and/or (iii) without notice of default or demand,
pursue and enforce Payee's rights and remedies under the Loan Documents, or
otherwise provided under or pursuant to any applicable law or agreement;
provided, however, that if any Event of default specified in





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Section 6.1(g) or (h) occurs, the principal of, and all interest on, this Note
and other liabilities hereunder shall thereupon become due and payable
concurrently therewith.

       7.     WAIVERS.  Waiver of any provision of this Note by Payee shall not
be deemed to constitute a waiver of any other provision hereunder, whether or
not similar, nor shall any waiver constitute a continuing waiver.  No waiver
shall be binding unless executed in writing by Payee.

       8.     LIMITATIONS ON USURY.  Regardless of any provisions contained in
this Note, Payee shall never be deemed to have contracted for or be entitled to
receive, collect or apply as interest (whether called interest herein or deemed
to be interest by operation of law or judicial determination) on this Note, any
amount in excess of the highest lawful rate, and, in the event Payee ever
receives, collects or applies as interest any such excess, such amount which
would be excessive interest shall be applied to the reduction of the unpaid
principal balance of this Note, and, if the principal balance of this Note is
paid in full, any remaining excess shall forthwith be paid to Maker.  In
determining whether or not the interest paid or payable under any specific
contingency exceeds the highest lawful rate, Maker and Payee shall, to the
maximum extent permitted under applicable law, (i) characterize any
non-principal payment (other than payments which are expressly designated as
interest payments hereunder) as an expense, fee, or premium, rather than as
interest, (ii) exclude voluntary prepayments and the effect thereof, and (iii)
spread the total amount of interest throughout the entire contemplated term of
this Note so that the interest rate is uniform throughout such term.

       9.     MISCELLANEOUS.

              9.1.   Governing Law.  This Note shall be governed by, and
construed and enforced in accordance with, Texas law.

              9.2.   Binding Effect.  All of the terms, covenants,
representations, warranties and conditions herein shall be binding upon, and
inure to the benefit of, and be enforceable by, the parties and their
respective successors and assignees.

              9.3.   Attorneys' Fees.  If any party brings an action in
connection with the performance, breach or interpretation of this Note, or in
any action related hereto, the prevailing party in such action shall be
entitled to recover from the losing party in such action all reasonable
attorneys fees, court costs, costs of investigation, accounting, and other
costs reasonably incurred or related to such litigation.

              9.4.   Notices.  All notices, demands and other communications
required or permitted to be given hereunder shall be deemed to have been duly
given and received if in writing and (i) effective immediately if delivered
personally; or (ii) effective seventy-two (72) hours after mailing if deposited
in the United States mail, first class, postage prepaid, registered or
certified mail, return receipt requested, addressed as set forth below; or
(iii) effective upon confirmation of delivery if sent by telecopier to a
party's telecopier number set forth below and after twenty-four (24) hours, if
sent by a nationally recognized overnight courier (e.g., Federal Express,
D.H.L., etc.) to the party at such party's address set forth below:





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                 Maker:                       ErgoBilt, Inc.
                                              Attn:  Gerard Smith, President
                                              5001 Quorum Drive, Suite 147
                                              Dallas, Texas 75240
                                              Telecopier No.:  214-392-9719

                 With courtesy copy to:       Wolin, Fuller, Ridley & Miller LLP
                                              Attn:  Norman R. Miller, Esq.
                                              3100 Bank One Center
                                              1717 Main Street
                                              Dallas, Texas 75201
                                              Telecopier No.:  214-939-4949

                 Payee:                       Summit Partners Management Co.
                                              Attn:  Mr. Don V. Ingram
                                              2200 Ross Avenue
                                              Suite 4500, LB 170
                                              Dallas, Texas 75201
                                              Telecopier No.:  214-220-4349

                 With courtesy copy to:       Haynes and Boone, L.L.P.
                                              Attn:  Marc H. Folladori, Esq.
                                              1000 Louisiana Street, Suite 4300
                                              Houston, Texas 77002-5012
                                              Telecopier No.:  713-547-2600

       The addresses provided above may be changed by notice given to the other
party in accordance with this Paragraph.  A party's failure to provide a
courtesy copy shall not invalidate notice otherwise given in accordance with
this Paragraph.

                                        ERGOBILT, INC.

                                        By: /s/ GERARD SMITH       
                                            --------------------------------
                                            Gerard Smith, President         

Accepted and Agreed:

SUMMIT PARTNERS MANAGEMENT CO.

By: /s/ DON V. INGRAM    
    ----------------------------
    Don V. Ingram


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