Front Panel

Located halfway up under the front bezel section with the ventilation holes.

Photo available of the backside and a super-duper overlay and a bigger size front.

Connector List:

CTRL_PNL: Control Panel connector, 16-pin, two-row, jumper-spaced, Pin 1 is missing, blocked on the connector.
FNT_PNL: Front Panel (connects to motherboard). 34-pin, two-row, tight-spaced, Pin 21 is missing.
AUDIO_CABLE: Connects to motherboard. Single-row, 10-pin, tightly-spaced; Pin 7 is missing.
INTRUDER: Connects to the chassis intrusion detector switch. Single-row, 5-pin, jumper-spaced. 5-pin version of the 4-pin CD-AUDIO connectors.
EXT_SPK: Optionally connects to external speaker.
HP_OUT: Headphone out. Stereo 3.5mm jack.
USB_FNT: Front USB connectors. Double USB connector.

CTRL_PNL

From the pin-side:

Pin	Description	Connects to FNT_PNL Pin
1	Removed and blocked on the connector	—
2	PWR SWITCH LEFT SIDE (Both)	20
3	GND	GND
4	HDD LED NEG	22
5	PWR LED GREEN POS	23
6	HDD LED POS	5 thru R19
7	GND	GND
8	ESUP SWITCH RIGHT SIDE (Both)	28
9	PWR LED YELLOW POS	27
10	N/C	—
11	GND	GND
12	N/C	—
13	ESUP LED NEG	24
14	ESUP LED POS	5 Thru R20
15	GND	GND
16	GND	GND

FNT_PNL

From the pin-side:

Pin	Description	Connects to
1	INTRUDER 3	INTRUDER 3, FNT 32
2	VCC ??	FNT 3, FNT 4
3	VCC ??	FNT 2, FNT 4
4	VCC ??	FNT 2, FNT 3
5	LED VCC	CTRL 6 thru R19, CTRL14 thru R20
6	?
7	?
8	INTRUDER 5	INTRUDER 5
9	GND	GND
10	GND?	GND?
11	GND	GND
12	?
13	?
14	GND	GND
15	?
16	GND	GND
17	?
18	?
19	GND	GND
20	PWR SWITCH LEFT SIDE (Both)	CTRL 2
21	Pin removed	—
22	HDD LED NEG	CTRL 4
23	PWR LED GREEN POS	CTRL 5
24	ESUP LED NEG	CTRL 13
25	GND	GND
26	?
27	PWR LED YELLOW POS	CTRL 9
28	ESUP SWITCH RIGHT SIDE (Both)	CTRL 8
29	GND	GND
30	INTRUDER 1	INTRUDER 1
31	EXT_SPK 2	EXT_SPK 2
32	INTRUDER 3	INTRUDER 3
33	EXT_SPK 4	EXT_SPK 4
34	EXT_SPK 1	EXT_SPK 1

AUDIO_CABLE

From pin-side:

Pin	Description	Connects to
1	GND	GND
2	OUT LEFT	3.5 jack tip
3	GND	GND
4	OUT RIGHT	3.5 middle ring
5	GND	GND
6	?
7	Pin removed	—
8	?
9	?
10	GND	GND

INTRUDER

From pin-side:

Pin	Description	Connects to
1		FNT 30
2	GND	GND
3		FNT 1, FNT 30
4	GND	GND
5		FNT 8

EXT_SPK

From pin-side:

Pin	Description	Connects to
1		FNT 34
2		FNT 31
3	GND	GND
4		FNT 33

HP_OUT

From solder-side:

When unconnected to a 3.5 jack:

When connected to a jack:

Pin	Description	Connects to
1	SENSE	GND if connected, otherwise Base Ring (floats)
2	GND	GND
3	SENSE	GND if unconnected, otherwise floats
4	SENSE	GND if connected, otherwise Base Ring (floats)
5	GND	GND
6	SENSE	GND if unconnected, otherwise floats
7	Left channel	Tip
8	GND if connected, otherwise floats	Base Ring
9	Right channel	Middle Ring

USB_FNT

This I cannot be bothered with, way too many surface mounted components. You are welcome to drop me an email (@ 400sc-at-peterlada-dot-com) if you draw a circuit diagram, or have any info.