Computer Devices Dot

For more information, see this article's corresponding Wikipedia page: The_Dot_(computer).

Computer Devices Dot

Preliminary Information
Release Year	1983
Leak Risk	Low
Batteries	Soldered to CPU card
Mounting Technology	Through Hole, Sockets
Capacitor Types	Aluminum Electrolytic, Tantalum, Ceramic
Destructive Entry	No
Hardware Specifications
CPU	8088
Storage	3.5in Sony OA-D30V or OA-D31V pre-standard Drives
Power Requirements
Input Voltage	120V AC
Power Connector	IEC C13/C14 Socket

The Dot by CDI was a portable IBM compatible-ish computer with built in CRT, printer, and 3.5in floppy drive(2).

Known Issues

Shuts off during use

Causes

• Probably PSU caps are bad

Solutions

• Recap PSU

Horizontal instability in image on CRT

Causes

• Probably CRT analog board caps are bad

Solutions

• Recap CRT analog board

Disassembly Notes

There is a very difficult to access screw to the right of the CRT that must be removed to gain full access to CRT analog board.

Original Parts

CRT Analog Board

Sanyo, DK7459NL

• 

Capacitor Specifications and Footprint Information

RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
C512	1	2200 µF	10 V	Through Hole	16mm	24mm	8mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 129
C620	1	1000 µF	35 V	Through Hole	16mm	24mm	8mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 32
C607, C509	2	4.7 µF	25 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 321
C673	1	22 µF	16 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 13
C504, C502	2	10 µF	16 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 207
C505	1	33 µF	16 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 47
C510	1	1 µF	25 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Sanyo	C 27
C501	1	2.2 µF	50 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 156
C656	1	22 µF	25 V	Through Hole	5mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 17
C511	1	4.7 µF	25 V	Through Hole	8mm	12mm	5mm	85 °C	Aluminum Electrolytic	Sanyo	O.E 28
C506, C508, C606	3	220 µF	16 V	Through Hole	10mm	12mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 442
C210	1	100 µF	100 V	Through Hole	13mm	20mm	5mm	85 °C	Aluminum Electrolytic	Nichicon	SE (M)
C652, C651	2	10 µF	160 V	Through Hole	10mm	15mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 172
C612	1	470 µF	25 V	Through Hole	10mm	20mm	5mm	85 °C	Aluminum Electrolytic	Rubycon	CE W M 172
C621	1	4.7 µF	50 V	Through Hole	18mm	32mm	7mm	85 °C	Non-Polar Aluminum Electrolytic	Rubycon	H. D.

Integrated Circuits

RefDes	Qty	Model Number/Part Number	Manufacturer (If Applicable)	Explanation	Datasheet
	1	HD74LS123P	Hitachi	Monostable Multivibrator	SN74LS123

PSU Board

0002-14506, D51274, Rev C, 22-3-3285

• 

Capacitor Specifications and Footprint Information

RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
C16, C20	2	470 µF	200 V	Through Hole	25mm	56mm	10mm	85 °C	Aluminum Elecytolytic	Marcon	HPW-N
C19, C2	2	220 µF	35 V	Through Hole	10mm	20mm	5mm	85 °C	Aluminum Elecytolytic	ic	RARA
C12	1	4.7 µF	50 V	Through Hole	4mm	8mm	5mm	105 °C	Aluminum Elecytolytic	Qunio	GR
C3, C23, C24, C25	4	2200 µF	35 V	Through Hole	18mm	36mm	10mm	105 °C	Aluminum Elecytolytic	Marcon	CE-US
C18	1	470 µF	16 V	Through Hole	10mm	20mm	5mm	105 °C	Aluminum Elecytolytic	Marcon	CE-US
C15	1	33 µF	16 V	Through Hole	5mm	8mm	5mm	85 °C	Aluminum Electrolytic	Panasonic	S

Integrated Circuits

RefDes	Qty	Model Number/Part Number	Manufacturer (If Applicable)	Explanation	Datasheet
	2	LM339N	National Semiconductor	Quad Differential Comparators	LM339
	1	LM358N	National Semiconductor	Low Power Dual OpAmp	LMx58
	1	SG3549		Current Sense Latch	SG3549

Q160 Logic Board

28-3-7097

Capacitor Specifications and Footprint Information

RefDes	Qty	Capacitance	Voltage	Mount	Diameter/Size	Height	Lead Spacing	Temp	Type	Brand	Series
	3	15 µF	35V	Through Hole	5mm	8mm	5mm	85 °C	Aluminum Electrolytic	IC

Replacement Parts

CRT Analog Board

Capacitors

RefDes	Qty	Compatible Part Number	Order Links
C512	1	EKZH250ELL222ML20S	Digikey
C620	1	35WXA1000MEFC16X16	Digikey
C607, C509	2	UVR1V4R7MDD1TA	Digikey
C673	1	UVR1C220MDD1TA	Digikey
C504, C502	2	ECA-1EM100B	Digikey
C505	1	ECA-1CM330B	Digikey
C510	1	UPX1V010MPD	Digikey
C501	1	50YXJ2R2MTA5X11	Digikey
C656	1	50YXJ22MTA5X11	Digikey
C511	1	UVR1V4R7MDD1TA	Digikey
C506, C508, C606	3	EEU-FR1C221B	Digikey
C210	1	100YXJ100MT810X20	Digikey
C652, C651	2	UPS2C100MPD1TD	Digikey
C612	1	25YXG470MEFCT810X16	Digikey

CRT Horizontal Deflection Capacitor

RefDes	Qty	Compatible Part Number	Notes
C621	2	UVP1A472MHD or ECE-A0JN682U	WARNING: There is no suitable replacement for the original capacitor. The original rated ripple current is not matched by any currently produced capacitors. The best recommendation I have is to put two of the stated capacitors here in parallel to attempt to get enough ripple current endurance. But this is UNTESTED.

Integrated Circuits

RefDes	Qty	Compatible Part Number	Order Links
	1	SN74LS123N	DigiKey Mouser LCSC

PSU Board

Capacitors

RefDes	Qty	Compatible Part Number	Order Links
C16, C20	2	LGU2D471MELZ	Digikey
C19, C2	2	UVZ1V221MPD1TD	Digikey
C12	1	UPS1J4R7MDD1TA	Digikey
C3, C23, C24, C25	4	50MXG2200MEFCSN20X25	Digikey
C18	1	UVZ1C471MPD1TA	Digikey
C15	1	EEU-FR1V330B	Digikey

Integrated Circuits

RefDes	Qty	Compatible Part Number	Order Links
	2	LM339N	DigiKey Mouser LCSC
	1	LM358N/NOPB	DigiKey Mouser LCSC

Q160 Logic Board

Capacitors

RefDes	Qty	Compatible Part Number	Order Links
	3	EEA-GA1H150B	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/

Related Links

• Videos or other things that might be helpful to check out