A500 does not reset on C-A-A

[LoadWB]

I have two A500s here that will not reset when pressing CTRL-Amiga-Amiga.  Nothing else seems to be affected -- no other keys are bad or stuck, and each key works properly independently.  Any ideas?

[steve30]

and each key works properly independently.

Do you mean that the CTRL and Amiga keys work properly when using the Amiga?

My A500+ also does not reset with CTRL+A+A, but upon testing it, Neither the CTRL, Amiga, ALT or SHIFT keys work when using the Amiga, which suggests a faulty keyboard.

[Zac67]

Two possibilities: either one of the C-A-A keys is broken or the _KBRESET line from the keyboard is.

[Lockon_15]

Or maybe one of 2 transistors on keyboard PCB is gone for good...

[LoadWB]

Lockon_15 wrote:
Or maybe one of 2 transistors on keyboard PCB is gone for good...

Anyone have a schematic of the A500 keyboard?  I don't think there's one in the manual.

[taunusand]

In my A500 manual (danish) there is a diagram.

But here are the pinout:
1: Clock
2: Data
3: Reset
4: +5Volt
5: nc (No connection)
6: Gnd
7: Power led
8: Disk activity led

Maybe something with in 5 is the problem?

[amigaksi]

>Anyone have a schematic of the A500 keyboard? I don't think there's one in the manual

There are schematics in the "Introduction to Amiga 500" manual (some introduction).  In the version that I have the keyboard pins 1 and 2 are reversed (found out the hard way-- experimentally).  However, the reset and ground pins were correctly labelled.  Try connecting the reset to the ground pin (carefully) and if that resets the Amiga, you know it's the keyboard and not the motherboard.  Or if not technically inclined, try the Peripheral Simulator here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320167447376

If it works and allows you to reset your Amiga from the PC, it's not the reset line on your motherboard.

[Speelgoedmannetje]

Zac67 wrote:
Two possibilities: either one of the C-A-A keys is broken or the _KBRESET line from the keyboard is.

There is no _KBRESET line on any type of keyboard I have ever seen. :-?
Only keyboard data, clock, ground and +5v.
Isn't it some option in the OS/kickstart that has disabled this?

[Zac67]

 :roll:

[amigaksi]

Should be clock (_KBCLOCK) on pin 1 and data (_KBDATA) on pin 2 instead of what the Introduction to Amiga 500 Manual schematic states (in Appendix F).

[CLS2086]

Hi,
try also to disassemble your keyboard and use electronic spray cleaned on the transfert film.