EXHIBIT 99 b

                       AMENDMENT NUMBER THREE
                         TO CREDIT AGREEMENT


         THIS  AMENDMENT   NUMBER  THREE   TO  CREDIT   AGREEMENT   (this
  "Amendment") is made as of the 10th day of February, 2000, by and among
  CIRCUIT SYSTEMS,  INC., an  Illinois corporation  ("Circuit  Systems"),
  CIRCUIT SYSTEMS  OF TENNESSEE,  L.P., a  Tennessee limited  partnership
  ("CSTLP") and  SVPC CIRCUIT  SYSTEMS,  INC., a  California  corporation
  ("SVPCCSI"  and   together  with   Circuit  Systems   and  CSTLP,   the
  "Borrowers"), and  LASALLE  BANK NATIONAL  ASSOCIATION,  f/k/a  LaSalle
  National Bank ("Bank"), as Agent for the Lenders now or hereafter named
  in the Loan Agreement (hereinafter defined).

                             BACKGROUND

         A.   Borrowers are obligated and indebted to Bank and the  other
  Lenders  pursuant to the terms  of that certain Credit Agreement  dated
  as of January 6,  1999, as amended and  supplemented from time to  time
  (the  "Loan  Agreement"),  and  various  instruments,  agreements   and
  documents executed  in connection  therewith (collectively,  the  "Loan
  Documents"), pursuant to which Lenders have made loans and advances  to
  the Borrowers.

         B.   Borrowers have  informed  Lenders  that  Borrowers  are  in
  breach of certain provisions of the Loan Agreements, including  without
  limitation,  certain  financial  covenants   set  forth  in  the   Loan
  Agreements.

         C.   Borrowers have  requested  that  Bank (a)  amend  the  Loan
  Agreement to make  additional funds  available to  Borrowers under  the
  revolving loan facility, and (b) waive those Events of Default referred
  to in Section 1 hereof on the terms and conditions contained herein.

         D.   Capitalized terms used herein but not defined herein  shall
  have the same meanings assigned to them in the Loan Documents.

         NOW, THEREFORE, in consideration of the premises set forth above
  and the mutual promises contained in  this Consent, and for other  good
  and valuable consideration, the receipt and sufficiency of which hereby
  are acknowledged, Borrowers and Bank, on  behalf of the Lenders,  agree
  as follows:

         1.   WAIVER.   Effective  upon  the execution  and  delivery  by
  Borrowers of this Amendment to Bank and satisfaction of the  conditions
  precedent  set  forth  herein,  Bank  hereby  waives  any  defaults  in
  existence under Section 6.4 the Loan  Agreement.  The waiver set  forth
  in this Section 1 shall be a limited waiver and shall not constitute  a
  waiver of other violations or any  subsequent violations, whether of  a
  different or like nature, nor shall  it constitute a course of  conduct
  or dealing.
<PAGE>
         2.   AMENDMENTS TO LOAN AGREEMENT

         2.1  The first full  paragraph of the  definition of  "Borrowing
  Base" set forth in Section 1.1 of the Loan Agreement is hereby  amended
  in its entirety to read as follows:

         "Borrowing Base:

         For the Revolving Credit Loans: The lesser of $16,000,000 or the
         sum of (i) 85% of the face amount of Eligible Accounts, (ii) the
         lesser of  $3,000,000 or  the sum  of (1)  50% of  the value  of
         Eligible Finished Goods  and (2) 75%  of the  value of  Eligible
         Finished Goods on Consignment, (iii) the sum of 40% of the value
         of SVPCCSI's Raw Materials Inventory and 50% of the value of all
         other Borrowers'  Raw  Materials  Inventory,  but  in  no  event
         greater than  $2,000,000, and  (iv) 60%  of the  current  market
         value of the  common stock  of SigmaTron  held by  CSI, as  such
         market value is quoted on a recognized securities exchange,  but
         in no event greater than $2,000,000."

         2.2  The definition of "Eligible Finished Goods on  Consignment"
  set forth in Section 1.1 of the Loan Agreement is hereby amended in its
  entirety to read as follows:

         "Eligible Finished Goods on  Consignment" means that portion  of
         the Borrowers' finished  goods Inventory  (i) which  is held  by
         Lucent Technologies, Inc., Berg Electronics, Inc., or such other
         Account Debtors  approved by  Agent in  writing, (ii)  which  is
         subject  to  a  consignment  agreement  which  is  in  form  and
         substance acceptable to  Agent, (iii) is  located in the  United
         States, and  (iv) in  which the  Agent holds  a perfected  first
         priority Lien."

         2.3  The definition of "Revolving  Credit Termination Date"  set
  forth in Section  1.1 of the  Loan Agreement is  hereby amended in  its
  entirety to read as follows:

         "Revolving Credit Termination Date means August 1, 2001."

         2.4  The definition of  "Term Loan Maturity  Date" set forth  in
  Section 1.1 of the Loan Agreement is hereby amended in its entirety  to
  read as follows:

         "Term Loan Maturity Date means August 1, 2001."

         2.5  The Loan Agreement is hereby  amended to provide that  upon
  the expiration of any  LIBOR-Rate Interest Period  with respect to  any
  Revolving Loan Tranche or Term Loan Tranche in existence on the date of
  this Amendment, all such Revolving Loan Tranches and Term Loan Tranches
  shall thereafter bear interest  at the Base  Rate Option and  Borrowers
  shall not be permitted to elect the LIBOR-Rate Option.
<PAGE>
         2.6  Upon the effectiveness  of this  Amendment, the  applicable
  Margin for  Base Rate  Loans  and the  Pricing  Matrix for  the  Unused
  Availability Fee shall be as follows and Annex B to the Loan  Agreement
  shall be amended accordingly:

         "Applicable Margin for the Revolving Credit Loans and Term Loan:

          Funded Debt/                                Unused Availability
          EBITDA Ratio                    Prime +             Fee
          ------------                    -------     -------------------
          Greater than or equal to          .75%             .50%
          5.25 to 1.0

          Less than 5.25 to 1.0 but         .50%             .375%
          greater than or equal to
          4.50 to 1.0

          Less than 4.50 to 1.0 but         .50%             .25%
          greater than or equal to
          3.50 to 1.0


          Funded Debt/                                Unused Availability
          EBITDA Ratio                    Prime +             Fee
          ------------                    -------     -------------------
          Less than 3.50 to 1.0 but         .25%             .25%
          greater than or equal to
          2.50 to 1.0

          less than 2.50 to 1.0             .0%              .125%


         2.7  Sections  6.4(a)-(d)  of  the  Loan  Agreement  are  hereby
         amended in their entirety to read as follows:

         "6.4(a) Minimum EBITDA.   Borrowers'  consolidated EBITDA  shall
         not be less than  the amounts set forth  in the table below  for
         the indicated  fiscal periods  of  Borrowers' Fiscal  Years  set
         forth below ending as of the  last day of such indicated  fiscal
         period:


           Fiscal Period of Borrowers       Minimum EBITDA
           --------------------------       --------------
           Nine months ending 1/31/00         $4,150,000

           Ten months ending 2/29/00          $5,000,000

           Eleven months ending 3/31/00       $6,000,000

           Twelve months ending 4/30/00       $7,100,000

           Three months ending 7/31/00        $2,775,000

           Six months ending 10/31/00         $6,100,000

           Nine months ending 1/31/01         $9,000,000

           Twelve months ending 4/30/01       $12,000,000
<PAGE>

         "6.4(b) Adjusted Debt Service Ratio.   For the indicated  fiscal
         periods of Borrowers' Fiscal Years set forth below ending as  of
         the last day of such  indicated fiscal periods, Borrowers  shall
         not permit the ratio of  (i) Borrowers' consolidated EBITDA  for
         such period, less (1) the sum of Borrowers' consolidated Capital
         Expenditures  for  such  period,   minus  increased  long   term
         Indebtedness of Borrowers incurred  during such period, and  (2)
         Borrowers' cash  income  taxes paid  for  such period,  to  (ii)
         Borrowers' consolidated Debt Service  for such period,  measured
         as of the last day of such indicated fiscal periods, to be  less
         than the  ratios  set  forth  below  for  the  indicated  fiscal
         periods:

           Fiscal Period                    Minimum  Adjusted Debt
           of Borrowers                     Service Ratio
           --------------------------       -----------------------
           Nine months ending 1/31/00       - 0.10 to 1.0

           Ten months ending 2/29/00          0.30 to 1.0

           Eleven months ending 3/31/00       0.35 to 1.0

           Twelve months ending 4/30/00       0.40 to 1.0

           Three months ending 7/31/00        0.80 to 1.0

           Six months ending 10/31/00         0.90 to 1.0

           Nine months ending 1/31/01         1.00 to 1.0

           Twelve months ending 4/30/01       1.00 to 1.0


         "6.4(c) Minimum  Tangible Net  Worth.   Borrowers'  Consolidated
  Tangible Net Worth shall  not be less than  the amount set forth  below
  for the indicated fiscal periods of  Borrowers' Fiscal Years set  forth
  below ending as of the last day of such indicated fiscal periods:


             Fiscal Period of Borrowers       Minimum Tangible
                                                 Net Worth
             --------------------------       ----------------
             Nine months ending 1/31/00          $6,400,000

             Ten months ending 2/29/00           $8,750,000

             Eleven months ending 3/31/00        $8,900,000

             Twelve months ending 4/30/00        $9,000,000

             Three months ending 7/31/00         $9,175,000

             Six months ending 10/31/00          $9,600,000

             Nine months ending 1/31/01          $9,750,000

             Twelve months ending 4/30/01       $10,000,000
<PAGE>
         "6.4(d) Maximum  Debt to  Tangible  Net Worth  Ratio:  Borrowers
         shall not  permit the  ratio of  the sum  of their  consolidated
         Indebtedness, less all Indebtedness of Borrowers subordinated to
         the  Obligations  by  written  agreements  acceptable  to  Agent
         ("Subordinated Debt")  to  the sum  of  Borrowers'  consolidated
         Tangible Net Worth, plus Subordinated Debt  to be more than  the
         ratios set  forth  below for  the  indicated fiscal  periods  of
         Borrowers' Fiscal Years set  forth below ending  as of the  last
         day of such indicated fiscal periods:


                                              Maximum Debt to
           Fiscal Period                     Tangible Net Worth
           of Borrowers                            Ratio
           --------------------------           ------------
           Nine months ending 1/31/00           10.20 to 1.0

           Ten months ending 2/29/00            7.75 to 1.0

           Eleven months ending 3/31/00         7.75 to 1.0

           Twelve months ending 4/30/00         7.75 to 1.0

           Three months ending 7/31/00          7.75 to 1.0

           Six months ending 10/31/00           7.25 to 1.0

           Nine months ending 1/31/01           6.75 to 1.0

           Twelve months ending 4/30/01         6.40 to 1.0


         2.8  Section 6.1 of the Loan Agreement is hereby amended to  add
  the following new subsection (vi) thereto:

         "(vi)     Indebtedness of (1) CSI  to Tribhovan M. Patel,  Samir
         Patel, Sejal Patel and Impex Electronics, Inc., (2) Indebtedness
         of SVPCCSI and CSI to  H.O.T.L.R.T., Inc., and (3)  Indebtedness
         of CSI to Tribhovan  M. Patel, as assignee  of Brijesh H.  Shah,
         Dahyabhai S. Patel, Kiran Patel, Tribhovan M. Patel, as assignee
         of Stan Menezes, P.J. Patel, Hasumati  D. Patel, P.J. Patel,  as
         assignee of Brijesh H. Shah and  P.J. Patel as assignee of  Stan
         Menezes,  all  of  which   Indebtedness  in  (1)-(3)  above   is
         subordinated to  the  repayment  of  Borrowers'  Obligations  to
         Lenders, by written agreements on terms acceptable to Agent."
<PAGE>
    3.   REAFFIRMATIONS OF COLLATERAL DOCUMENTS

         (a)  Borrowers are parties to each of the following documents:

              (i) Security Agreement (Inventory, Equipment, Accounts  and
              General Intangibles) dated January 6, 1999;

              (ii) Mortgage,  Assignment of  Leases and  Rents,  Security
              Agreement, Fixture Filing and Financing Statement dated  as
              of January 7, 1999 and filed with the Cook County, Illinois
              Recorder on January 13, 1999 as Document No. 99037717  (the
              "Elk Grove Village Mortgage"), as heretofore amended;

              (iii) Mortgage, Assignment  of Leases  and Rents,  Security
              Agreement, Fixture Filing and Financing Statement dated  as
              of January 7, 1999 and filed with the Lake County, Illinois
              Recorder on February 8, 1999  as Document No. 4294762  (the
              "Antioch Mortgage"), as heretofore amended; and

              (iv)  Deed  of  Trust,  Assignment  of  Leases  and  Rents,
              Security Agreement, Fixture Filing and Financing  Statement
              dated as of January 7, 1999 and filed with the Santa  Clara
              County, California Recorder on January 15, 1999 as Document
              No. 14600088 (the  "Santa Clara  Mortgage"), as  heretofore
              amended.

         The documents listed in  subsections (i) through (iv),  together
  with any and all other  instruments, documents and agreements  granting
  to Lender a security interest in  all personal property, real  property
  and  fixtures  of  Borrowers,  are  collectively  referred  to  as  the
  "Security Agreements".

         (b)  Each Borrower hereby expressly reaffirms and assumes all of
  its  obligations  and  liabilities  as   set  forth  in  the   Security
  Agreements, agrees that the  obligations secured thereby shall  include
  all obligations of such Borrower to Lender under the Loan Agreement, as
  amended from time to time, including  this Amendment, and agrees to  be
  bound by and abide by and operate and perform under and pursuant to and
  comply fully with all of the terms, conditions, provisions, agreements,
  representations, undertakings, warranties,  and covenants contained  in
  the Security Agreements, in so far as such obligations and  liabilities
  may be modified by this Amendment.

         4    REPRESENTATIONS AND WARRANTIES.   To induce  Bank to  enter
  into this Amendment, Borrowers represent and warrant to Bank that:

         (a)  Representations and Warranties.   On the  date hereof,  the
  representations and warranties set forth in the Loan Documents are true
  and correct with  the same effect  as though  such representations  and
  warranties had been made on the date hereof, except to the extent  such
  representations and warranties expressly relate to an earlier date.

         (b)  Events of Default.  On the date hereof, no Event of Default
  (other than those being waived hereby) under any of the Loan  Documents
  has occurred and is continuing.
<PAGE>
         (c)  No  Conflict.    The  execution  and  performance  by   the
  Borrowers of this  Amendment and the  consummation of the  transactions
  contemplated by the Amendment to Pledge Agreement will not (i)  violate
  any provision  of  law, any  order  of any  court  or other  agency  of
  government, the Articles of Incorporation  or ByLaws of either  Circuit
  Systems or  SVPCCSI  or the  Partnership  Agreement of  CSTLP  or  (ii)
  violate any indenture, contract, agreement or other instrument to which
  any Borrower is a party, or  by which its property  is bound, or be  in
  conflict with, result  in a breach  of or constitute  (with due  notice
  and/or lapse of time)  a default under,  any such indenture,  contract,
  agreement or other instrument or result  in the creation or  imposition
  of any lien, charge or encumbrance of any nature whatsoever upon any of
  the property or assets of any Borrower.

         5.   CONDITIONS PRECEDENT.  The effectiveness of this  Amendment
  and the agreement by Bank to  waive the existing Events of Default  and
  enter into  this  Amendment  is subject  to  the  following  conditions
  precedent:

         (a)  Borrowers shall have delivered to the Bank an executed copy
  of this Amendment.

         (b)  Circuit  Systems  shall  have  delivered  to  the  Bank  an
  executed copy  of an  Amendment  to Pledge  Agreement  in the  form  of
  Exhibit A hereto,  together with share  certificates evidencing all  of
  the issued and outstanding shares of  common stock of Infovision,  Inc.
  and an executed assignment separate from certificate in blank.

         (c)  Circuit Systems and SVPCCSI shall have delivered to Bank  a
  copy  of  the  resolutions  or  written  consent  of  their  Boards  of
  Directors, certified  to  be true  and  correct by  their  Secretaries,
  authorizing this Amendment.

         (d)  Circuit Systems shall have  delivered to Bank the  original
  of the subordinated  notes, evidencing the  subordinated debt due  from
  Circuit Systems to Sejal Patel,  Samir Patel, Impex Electronics,  Inc.,
  and Tribhovan M. Patel,  together with evidence of  the receipt of  the
  proceeds of the subordinated loans by  Sejal Patel, Samir Patel,  Impex
  Electronics, Inc.,  and Tribhovan M. Patel to Circuit Systems.

         (e)  Circuit Systems shall  have delivered to  Bank an  executed
  copy of  a Subordination  Agreement, in  the  form attached  hereto  as
  Exhibit B, from each of Tribhovan  M.  Patel, Samir Patel, Sejal  Patel
  and Impex Electronics, Inc.

         (f)  Borrowers shall  have delivered  to  Bank an  Amendment  to
  Subordination Agreement  in  the  form of  Exhibit  C  attached  hereto
  executed by H.0.T.L.R.T., Inc. and Circuit Systems.

         (g)  Borrowers  shall  have  delivered  to  Bank  Amendments  to
  Subordination Agreements  in  the form  of  Exhibit D  attached  hereto
  executed by Circuit Systems, SVPCCSI and each of Tribhovan M. Patel  as
  assignee of Brijesh H. Shah, Dahyabhai S. Patel, Tribhovan M. Patel  as
  assignee of  Stan  Menezes, P.J.  Patel,  Kiran Patel,  P.J.  Patel  as
  assignee of Stan Menezes, P.J. Patel as assignee of Brijesh Patel,  and
  Hasumati D. Patel.
<PAGE>
         (h)  Borrowers  shall  have  delivered   to  Bank  an   executed
  consignment agreement, in  form acceptable to  Bank, between  Borrowers
  and Berg Electronics, Inc., together with evidence of the perfection of
  Bank's Lien on all Inventory consigned to Berg Electronics, Inc.

         (i)  Borrowers shall have delivered to Bank a Guaranty  executed
  by  Infovision,  Inc.  in  the  form  of  Exhibit  E  attached   hereto
  guarantying the  payment  of  Borrowers' Obligations  and  an  executed
  Security Agreement and Financing  Statements in the  form of Exhibit  F
  attached hereto granting Bank a Lien on the assets of Infovision,  Inc.
  as collateral security for Borrowers' obligations.

         (j)  Borrowers shall  have  delivered to  Bank  a  Subordination
  Agreement in the form of Exhibit G attached hereto executed by  Project
  Control Solutions,  Inc.  ("PCS")  and Infovision,  Inc.,  whereby  PCS
  subordinates the repayment of Infovision, Inc.'s obligations to PCS  to
  the repayment of Infovision, Inc.'s obligations to Bank.

         (k)  Borrowers shall have delivered to Bank executed Forbearance
  Agreements in form  acceptable to  Bank between  CSI and  each of  PCS,
  Kiran Patel,  Tribhovan  M. Patel,  as  assignee of  Brijesh  H.  Shah,
  Dahyabhai S. Patel, Tribhovan  M. Patel, as  assignee of Stan  Menezes,
  P.J. Patel, as  assignee of  Stan Menezes,  P.J. Patel  as assignee  of
  Brijesh Patel, and Hasumati D. Patel.

         (l)  Circuit Systems of Tennessee,  Inc., the corporate  general
  partner of CSTLP, shall have delivered to Bank evidence of all required
  partnership approvals for CSTLP to execute and deliver this Amendment.

         (m)  Borrowers shall  have  delivered  to  Bank  a  copy  of  an
  executed employment  agreement  between  CSI  and  Tribhovan  M.  Patel
  providing for  Tribhovan  M.  Patel's  employment  as  Chief  Operating
  Officer of CSI on terms acceptable to Bank.

         7.   GENERAL PROVISIONS.

         (a)  Except  as  herein  amended  or  modified,  the  terms  and
  provisions of the  Loan Documents shall  remain unchanged  and in  full
  force and effect and are in all other respects ratified and confirmed.

         (b)  This Amendment shall  be construed in  accordance with  and
  governed by the laws of the  State of Illinois, and the obligations  of
  Borrowers under  this  Amendment are  and  shall arise  absolutely  and
  unconditionally upon the execution and delivery of this Amendment.

         (c)  This  Amendment.  may   be  executed  in   any  number   of
  counterparts, each of  which shall be  deemed an original,  but all  of
  which taken together shall constitute one and the same instrument.

         (d)  Borrowers hereby agree  to pay  all out-of-pocket  expenses
  incurred by Bank  in connection with  the preparation, negotiation  and
  consummation  of  this  Amendment,  and  all  other  documents  related
  thereto, including without limitation, the  fees and expense of  Bank's
  counsel.
<PAGE>

         IN  WITNESS  WHEREOF,  Borrowers  and  Bank  have  caused   this
  Amendment to be duly executed by  their duly authorized officers,  each
  as of the day and year first above written.

                             CIRCUIT SYSTEMS, INC.



                             By:  __________________________
                             Title:____________________________

                             CIRCUIT SYSTEMS OF TENNESSEE, L.P.



                             By:  __________________________
                             Title:____________________________

                             SVPC CIRCUIT SYSTEMS, INC.



                             By:  __________________________
                             Title:____________________________

                             LASALLE BANK NATIONAL ASSOCIATION



                             By:  __________________________
                             Title:____________________________