Apple M0115 Extended Keyboard Issue

[Riverman]

I recently bought an Apple M0115 Extended Keyboard with orange Alps, which I've been dying to own for quite a while. It works great, except that the forward delete key doesn't work, and several other keys produce the forward delete key code along with their own. I verified the behavior with a key code app. The offending keys are the up arrow, 2 on the numpad, page up, and page down. I took a look at the backside of the board, and the keys don't seem to share common traces. I also popped the top off of the delete key switch, but didn't see anything odd inside there. Can someone help steer me in the right direction? Thanks!

[Findecanor]

Have there been any mods to it to it to make it work with a modern computer?

I would inspect the solder joints to the controller, to see if perhaps two pads have been bridged.

[Muirium]

Yes. If it's not USB modded, then what converter are you using? Those can be flaky.

[Riverman]

I'm using an old Griffin iMate I bought 20 years ago. It's never given me any problems, and unfortunately I don't have any other ADB keyboards to test it with at the moment. I have a few others, but they're packed away somewhere in my storage unit.

[Muirium]

The AEK (I & II) matrix can be found here.

Code: Select all

 	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	 
0	KP 9	numlk	 	scrlk	prtscr	F12	F10	F9	F7	F6	F5	F4	F3	F2	F1	esc	0
1	KP /	KP =	KP 8	pause	pgup	bksp	F11	0)	F8	7&	6^	4$	3#	2@	1!	`~	1
2	KP *	 	KP 7	 	pgdn	\|	=+	O	9(	8*	T	5%	 	 	 	 	2
3	KP -	 	KP 6	 	end	home	[{	-_	 	 	Y	G	 	 	 	 	3
4	KP 3	right	KP 5	 	del	ins	]}	P	K	I	 	R	E	W	Q	tab	4
5	KP enter 	KP 4	 	up	enter	'"	;:	L	 	U	 	D	 	 	 	5
6	 	 	KP +	left	 	.>	/?	,<	J	H	B	F	 	 	S	A	6
7	 	KP .	 	down	KP 2	KP 1	KP 0	M	N	 	space	V	C	X	Z	 	7
 	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	 

As you can see: all your offending keys are on the same column 4. Looks like a PCB issue.

[Riverman]

Thanks! That definitely does make it look like a PCB issue. I'll have to examine the board a little more closely and see what I can find. Hopefully whatever is causing the issue is on bottom. I don't see a good way to examine the top since the plate covers it all.