spacemanrocks Posted March 16, 2017 Share Posted March 16, 2017 Hi all, Quick question. Is it possible to determine if a STFM motherboard is PAL or NTSC just by looking at it? I have a STFM from a member here which did not have a power supply. Got one ordered, but I noticed the bottom of the STFM case is european. It's possible that the case may have been changed at some point, but before spending any more money and while I wait for the PSU to arrive, it'll be nice to know... the only info from the motherboard is that it's a C070789-00 rev.C... Thanks! Quote Link to comment Share on other sites More sharing options...
ParanoidLittleMan Posted March 17, 2017 Share Posted March 17, 2017 I did not see any USA (NTSC) Atari ST internals, but there is difference in color encoder crystal frequencies, what can look under shield where shifter chip is, usually it is in corner. PAL is 4.43361875 MHz, while NTSC is 3.579545 MHz. Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 18, 2017 Author Share Posted March 18, 2017 Ok so update..... while i'm waiting for my US PSU to arrive, i've hooked it up with a step down converter and the EU PSU that came separately with it to at least see if it powers on etc. It does power on, only to a plain white screen. The other weird thing is that I only get that white screen on channel 36, not 3 or 4 which I would expect in the USA. Does that mean this is a PAL unit? Also, the plain white screen usually indicates a TOS issue, right? Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 18, 2017 Author Share Posted March 18, 2017 Should also mention that aside from the green power light on the ST, there is no other activity at all, not even the floppy. Quote Link to comment Share on other sites More sharing options...
ParanoidLittleMan Posted March 18, 2017 Share Posted March 18, 2017 I guess it is easier to throw zillion questions than read one answer. Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 18, 2017 Author Share Posted March 18, 2017 I guess it is easier to throw zillion questions than read one answer. Gonna be honest here, I completely missed your post I'll check in a few minutes and report back Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 18, 2017 Author Share Posted March 18, 2017 I did not see any USA (NTSC) Atari ST internals, but there is difference in color encoder crystal frequencies, what can look under shield where shifter chip is, usually it is in corner. PAL is 4.43361875 MHz, while NTSC is 3.579545 MHz. Checked and yup, it's PAL...... so that's one mystery solved, now to try and figure out why i'm just getting a solid white screen and no floppy activity........ thank you! Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 19, 2017 Author Share Posted March 19, 2017 Kinda wish I could edit the title of this thread....... here's my current situation. The STFM is PAL. I'm using a european PSU but with a step down converter so I can use it here in the USA. Got the machine plugged into a TV on channel 34. Power the machine on, get a white screen with grey border. Power light solid green. No floppy activity at all, except a very brief glimpse of a light when powered on. If the floppy power is disconnected, the floppy light stays lit but no other activity. Machine does not boot to desktop even after leaving for half hour. Everything socketed has been reseated and the board has no signs of any physical damage.I do have a US power supply ordered but it still hasn't arrived. So this leaves me with thinking the TOS chips are bad. The machine came without any installed but had some loose with it (TOS 1.04 UK). Has anyone else experienced anything similar? I got this unit knowing it was untested so there was always a high chance it would be faulty, but now i've been messing around with it I really want to get it up and running! Quote Link to comment Share on other sites More sharing options...
ParanoidLittleMan Posted March 19, 2017 Share Posted March 19, 2017 It is normal that floppy light is on when drive is not powered, because of active low logic. Failure can be almost anything - bad CPU, Glue, RAM, ROM ... It is not easy to find error without equipment, replacement chips.. Quote Link to comment Share on other sites More sharing options...
spacemanrocks Posted March 19, 2017 Author Share Posted March 19, 2017 (edited) Yeah I agree.... i'm thinking at this point i'm just gonna put a wanted post out there for a STFM or a STE... when i got this I knew it was untested and didn't really care much, but now i've been trying to get it to work and i'm thinking about the games I played on it when I was a kid, I really want a working one now! Unfortunately I don't have any equipment for testing, never soldered etc etc Edited March 19, 2017 by spacemanrocks Quote Link to comment Share on other sites More sharing options...
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