MegaST2 won't start up properly
MegaST2 won't start up properly
I've got a MegaST2, which isn't properly working. When I switch on the machine, I only have a black screen. When I switch it on with the floppy drive disconnected, there is a flickering screen for a couple of seconds before it goes black.
However when I shortcircuit pin 17 and 18 of the CPU, it'll boot, but there are no icons on the desktop while the menu works correctly.
Someone before me soldered a mod ontop of the CPU as you can see in the picture below:

Please help. What can I do to solve this issue?
However when I shortcircuit pin 17 and 18 of the CPU, it'll boot, but there are no icons on the desktop while the menu works correctly.
Someone before me soldered a mod ontop of the CPU as you can see in the picture below:

Please help. What can I do to solve this issue?
Re: MegaST2 won't start up properly
I forgot:
Pin 18 shows 5Volts on a multimeter
Pin 17 just 0Volt
Pin 18 shows 5Volts on a multimeter
Pin 17 just 0Volt
-
- Posts: 298
- Joined: Tue Aug 22, 2017 4:27 am
Re: MegaST2 won't start up properly
The mod is a factory installed blitter patch.
Clearly you already suspect the reset circuitry. Have you tried checking U2 7407?
Clearly you already suspect the reset circuitry. Have you tried checking U2 7407?
Re: MegaST2 won't start up properly
Sorry, I'm a n00b to hardware and electronics...
what is "U2 7407"? And what to check?
what is "U2 7407"? And what to check?
Re: MegaST2 won't start up properly
Broken reset switch ? Check RESET with meter to GND and press and hold reset button.. voltage should change between 0V and 5V.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
Re: MegaST2 won't start up properly
Tried to. Reset switch seems to be broken. What to do now?
Re: MegaST2 won't start up properly
Replace the switch ?
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.
Re: MegaST2 won't start up properly
How? Do you sell any switches? Let's say, I don't necessarily need the switch. Can I just remove it?
- rubber_jonnie
- Moderator
- Posts: 818
- Joined: Thu Aug 17, 2017 7:40 pm
- Location: Essex
- Contact:
Re: MegaST2 won't start up properly
You mentioned earlier that you weren't too great with electronic stuff and hardware, so don't do this if you aren't competent at soldering.
Exxos has switches here: https://www.exxoshost.co.uk/atari/last/storenew/#0114
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2

Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk
Re: MegaST2 won't start up properly
Don't worry, my neighbour studied physics and technical computer science. He'll make it. Ordered the switch