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Re: Dead TT030 Repair
Posted: 25 Jun 2024 18:09
by grunwald
I was referring to other users having the same error code. :)
Re: Dead TT030 Repair
Posted: 25 Jun 2024 18:38
by Cyprian
grunwald wrote: 13 Jun 2024 15:32
Went back last night and focused on SEL and BNK5 signals. The following chart shows how memory is mapped dependent on whether the 2/8mb board is installed. The jumper on the board determines the state of BNK5.
interesting.
where did you get this documentation?
Re: Dead TT030 Repair
Posted: 25 Jun 2024 18:59
by grunwald
"TT MCU" on docs-dev
Re: Dead TT030 Repair
Posted: 25 Jun 2024 20:07
by Cyprian
grunwald wrote: 25 Jun 2024 18:59
"TT MCU" on docs-dev
great, thanks
Re: Dead TT030 Repair
Posted: 26 Jun 2024 16:29
by grunwald
It turns out that the Ctrl-Alt-Del issue was the keyboard. The Ctrl key is not registering.
Re: Dead TT030 Repair
Posted: 26 Jun 2024 16:45
by czietz
grunwald wrote: 26 Jun 2024 16:29
It turns out that the Ctrl-Alt-Del issue was the keyboard. The Ctrl key is not registering.
Perhaps check the keyboard membrane. When Ctrl stopped working on one of my TT keyboards, it was a damaged trace:
https://forum.atari-home.de/index.php/t ... #msg262044
... that I repaired:
https://forum.atari-home.de/index.php/t ... #msg262075
Since the damage was
underneath the green protective layer, I suspect a manufacturing defect that grew worse over time.
Re: Dead TT030 Repair
Posted: 26 Jun 2024 21:37
by stephen_usher
The other issue with the Mitsumi keyboards is that the conductive carbon impregnated rubber stops being conductive and you have to use carbon paint to fix it.
Re: Dead TT030 Repair
Posted: 27 Jun 2024 02:10
by atari030
I have the misfortune of have a TT and 2 MegaSTE KB's that need repairing. I figure the hassle of conductive paint repair might be easier than going to Best for three replacement mylars. I've not used conductive paint before, is there any specific type/brand to look at or are they much of a muchness?
Re: Dead TT030 Repair
Posted: 27 Jun 2024 02:29
by grunwald
I had a similar issue with one of my other keyboards. I fixed it at the time with thin copper tape and conductive epoxy. I used MG Chemicals 8331 which I had from another project. It works great but it costs more than a replacement mylar! I also picked up a new mylar from Best on my last order when I noticed they were back in stock. I'll pull the keyboard apart when I get a chance and repair or replace the mylar. The memory card issue is the one that's keeping me up at night....
Re: Dead TT030 Repair
Posted: 27 Jun 2024 06:49
by stephen_usher
If it’s the conductive rubber which has gone bad then changing the mylar won’t help.
When I did my TT keyboard I used the stuff that Exxos used to have in his store (but doesn’t sell any more).
I’ve got a remote control I need to fix and I’m going to experiment with Graphit 33.