SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* TPG ADVISORS INC (Last) (First) (Middle) TEXAS PACIFIC GROUP 301 COMMERCE STREET, SUITE 3300 (Street) FORT WORTH TX 76102 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ON SEMICONDUCTOR CORP [ ONNN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 02/04/2004
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.01	02/03/2004		S		13,000,000	D	$6.98	111,999,433(1)(2)(3)	I	Through funds managed by the Reporting Person(1)(2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Common Stock is beneficially owned by funds managed by the Reporting Person. Pursuant to Rule 16a-1(a)(2)(ii)(B) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), the Reporting Person is deemed to be the beneficial owner of the shares of the Issuer beneficially owned by TPG Semiconductor Holdings LLC only to the extent of the greater of the Reporting Person's direct or indirect interest in the profits or capital account of such entities. Pursuant to Rule 16a-1(a)(4) under the Exchange Act, this filing shall not be deemed an admission that the Reporting Person is, for purposes of Section 16 of the Exchange Act or otherwise, the beneficial owner of any securities owned by such funds in excess of such amount. David Bonderman, James G. Coulter and William S. Price, III (the "Shareholders") are officers, directors and the sole shareholders of the Reporting Person, and therefore may be deemed to beneficially own the shares owned by the Reporting Person.

2. Each Shareholder disclaims beneficial ownership of such shares in excess of the greater of his direct or indirect pecuniary interest in such shares.

3. Excludes 42,595,774 shares of Common Stock issuable upon the conversion of 10,000 shares of Series A cumulative convertible preferred stock held by TPG ON Holdings LLC, of which the Reporting Person is the general partner (excluding 851,915 additional shares of Common Stock expected to be issuable upon such conversion in respect of accumulated and unpaid dividends as of March 31, 2004).

	TPG Advisors, Inc., By : Richard A. Ekleberry, Vice President	02/04/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.