(A500+) Ctrl + Amiga + Amiga does not work.

[Protek]

Have you a possibility to try another keyboard? I've got the same problem with one A500 keyboard but Ctrl-A-A works with a spare one. Too bad that this one misses the Backspace key and it needs more than a cap. I wonder if it would help to swap the circuit boards between the keyboards or do I have to dismantle the whole thing to get the backspace button base?

[Protek]

If I remember correctly, you have a possibility to test the keys with some of the utils that come with the OS.

[Protek]

rkauer wrote:
 Checking again the keyboard circuit, the reset line/wire is connected to the pin #8 of the 74LS27 chip on the kb board.

So, stating the obvious here, swapping the chip does the trick?

[Protek]

sim085 wrote:

rkauer wrote:
 If the chip is faulty, yes.

By ‘chip’ do you mean the ‘transistor’? Sorry for my ignorance but I am not an electronics expert :$ I have also found an image of the A500+ keyboard internals. I found the (red) wire I have to test on this image but cannot identify the transistor. Does anyone have a pointer on where this transistor can be found on the A500+ keyboard?

Regards,
Sim085

The chip contains the transistor. Just look for '74LS27'. :-)

Looking from the picture at Amiga Hardware, it seems that the chips aren't socketed, so soldering is needed. I guess, I'll just swap the whole controller board.

[Protek]

rkauer wrote:
 Yes, HD is the manufacturer "code", 74LS27 is the chip code (a TTL-LS chip) and P means some sort of revision. But prefer to swap the TRANSISTOR before change the (inexpensive) TTL, since it's easier to do.

Yes, there seems to be some actual transistors there. Since chips usually have transistors integrated into them, I drew a wrong conclusion, when you talked about the reset line connected to the pin 8 of 74LS27. :oops: