Welcome, Guest. Please login or register.

Author Topic: CDTV keyboard issues  (Read 3448 times)

Description:

0 Members and 1 Guest are viewing this topic.

Offline Pat the Cat

Re: CDTV keyboard issues
« Reply #14 from previous page: February 26, 2021, 08:01:24 AM »

I have individual 10k ohm resistors. I was wondering if there's a way to hack them temporarily on to the connections to see if that'll fix things before replacing RP6 outright. Possible?


Hmmm... would mean soldering to the pins of the chip. (2 pull up resistors, one for kclock, one for kdat).

If you had a IC socket to solder to, and plug the even CIA on top, then yes. I'd be wary about soldering direct to a CIA chip, they seem a bit fragile (very prone to static shock).

I've seen somebody blow up a CIA chip just doing a continuity test on a live Amiga (GadgetUK164). All he was doing was measuring voltage to the serial port.

If you have a socket, it's worth doing just to make sure it really does fix the keyboard problem.

Changing a resistor pack means dismounting the whole board, worth looking for any other faults first (battery? etc etc etc).
"To recurse is human. To iterate, divine."

A1200, Vanilla, Surf Squirrel, SD Card, KS 3.0/3.z, PCMCIA dev
A500, Vanilla, A570, Rev 5, KS 1.2/1.3 Testbench system
Rasp Pi, UAE4ARM, 3D laser scanner, experimental, hoping for AmigaOS4Arm, based on Watterott Fabscan Pi
 

Offline Pat the Cat

Re: CDTV keyboard issues
« Reply #15 on: February 26, 2021, 08:06:33 AM »
Oh hang on a minute - the +5V is going to take the path of least resistance, ie the RP6 resistor pack.

You will HAVE to remove it for testing with conventional resistors, which is going to mess up other pull signals on RP6.

Wait for replacement. I'm 95% sure a new resistor pack will fix it.
"To recurse is human. To iterate, divine."

A1200, Vanilla, Surf Squirrel, SD Card, KS 3.0/3.z, PCMCIA dev
A500, Vanilla, A570, Rev 5, KS 1.2/1.3 Testbench system
Rasp Pi, UAE4ARM, 3D laser scanner, experimental, hoping for AmigaOS4Arm, based on Watterott Fabscan Pi
 

Offline hishamkTopic starter

Re: CDTV keyboard issues
« Reply #16 on: March 18, 2021, 08:17:03 PM »
So I replaced the 10k resistor pack and also the 10uf 50v cap by the keyboard port (the old one was fine though). Still no joy, exactly the same behavior.
2x A1000, 2x A2000, 1x A3000, 4x A1200, 3x A500, 1x CDTV, 1x CD32, 2x Pegasos II, 1x EFIKA
 

Offline Pat the Cat

Re: CDTV keyboard issues
« Reply #17 on: March 18, 2021, 08:24:26 PM »
It looks like it's RP6. The resistance is pretty shot for 40 and 39 against +5V. It's around 2 ohm.



Is that still the case, pins 39 and 40 shorted to 5 volts with next to no resistance? Take the chip out, then measure with keyboard connected and unconnected.

EDIT: There has to be something shorting those pins out either to 5V or to 0V. It could be the lead after all... but you did check for no shorts between any of the pins.
« Last Edit: March 18, 2021, 09:01:56 PM by Pat the Cat »
"To recurse is human. To iterate, divine."

A1200, Vanilla, Surf Squirrel, SD Card, KS 3.0/3.z, PCMCIA dev
A500, Vanilla, A570, Rev 5, KS 1.2/1.3 Testbench system
Rasp Pi, UAE4ARM, 3D laser scanner, experimental, hoping for AmigaOS4Arm, based on Watterott Fabscan Pi
 

Offline moulder

  • Newbie
  • *
  • Join Date: Mar 2024
  • Posts: 1
  • Country: pl
    • Show only replies by moulder
Re: CDTV keyboard issues
« Reply #18 on: March 16, 2024, 02:55:52 PM »
Did you manage to solve keyboard problem? I have similar issue except my keyboard reacts to the reset. Dont know what is the reason. Keyboard is ok - I checked it on another cdtv.