Texas Instruments Home Computer 99/4A

TI-99/4A
Preliminary Information
Release Year	1979
Leak Risk	Not Sure
Batteries	None
Mounting Technology	Through Hole, Sockets
Capacitor Types	Aluminum Electrolytic
Destructive Entry	No

For more information, see this article's corresponding Wikipedia page: TI-99/4A.

Original Parts

Power Supply

4A/PS

NO

1049689-2

Capacitor Specifications and Footprint Information
RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
C7, C10	2	47 µF	16 v	THT	6mm	12mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)
C8	1	1000 µF	25 v	THT	13mm	26mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)
C9	1	3300 µF	35 v	THT	22mm	39mm	Axial	85 °C	Electrolytic	Nichicon	(M)
C12	1	4.7 µF	50 v	THT	6mm	12mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)
C15	1	470 µF	12 v	THT	12.5mm	24mm	5mm	105 °C	Electrolytic	Nippon Chemi-Con	CERX

Main Board

The main board of the TI-99/4A has very little silkscreening. The only permanent marking on the board are an unrecognizable symbol followed by "-24 (ET) 246".

Capacitor Specifications and Footprint Information
RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
C1, C2, C7	3	100 µF	16 v	THT	8mm	16mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)
C3	1	10 µF	16 v	THT	5mm	12mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)
C4, C5, C6, C8, C9	4	22 µF	16 v	THT	6mm	12mm	Axial	85 °C	Electrolytic	Nichicon	SE(M)

The reference designations used for the main board here are not official as there are no designations silkscreened onto the PCB. See the image of the main board for the designations.

Replacement Parts

Basic PCB Name

Capacitors
RefDes	Qty	Compatible Part Number	Order Links
			Digikey

If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search.

Kits

Digikey BOM: https://www.digikey.com/

References