Can all registered uses please login, even just for a few minutes..
It helps build a picture where our "good traffic" is coming from..
Thanks :)

Atari Mega ST 1 Rev 1 no boot

Problems with your machine in general.
Dwh18
Posts: 26
Joined: Fri Feb 21, 2025 8:38 am

Re: Atari Mega ST 1 Rev 1 no boot

Post by Dwh18 »

stephen_usher wrote: Tue Mar 11, 2025 7:51 am Sounds like you need to put a terminal on the serial port and use the diag cartridge. It’s failing before it can properly display anything on the screen.

However, having a red screen is a positive sign as that means that it’s reading the ROM and starting the diagnostics.
Well, that's another issue.... already tried that only getting some (not many) garbage on screen... already tested cable with another Atari and all good
User avatar
stephen_usher
Site sponsor
Site sponsor
Posts: 7464
Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
Contact:

Re: Atari Mega ST 1 Rev 1 no boot

Post by stephen_usher »

This suggests that the system can't talk to the MFP (68901) correctly or the MFP clock isn't working. Check pins 17 and 18 for oscillation from the crystal circuit. It should be 2.4576MHz.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 15073
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Atari Mega ST 1 Rev 1 no boot

Post by rubber_jonnie »

Dwh18 wrote: Tue Mar 11, 2025 10:11 am
rubber_jonnie wrote: Tue Mar 11, 2025 8:30 am

So is it a completely black screen or a black screen in low reswith a white border?

@stephen_usher is right about the the red screen.
COmpletely black screen
RAM errors tend to show as a white border and black screen, I think you have something entirely different going on.

I'd try looking at what @stephen_usher has suggested.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Dwh18
Posts: 26
Joined: Fri Feb 21, 2025 8:38 am

Re: Atari Mega ST 1 Rev 1 no boot

Post by Dwh18 »

Well, almost quitting and leaving this Motherboard and searching for a new one... anyone in EU that repairs Ataris?
User avatar
PhilC
Moderator
Moderator
Posts: 7524
Joined: Fri Mar 23, 2018 8:22 pm

Re: Atari Mega ST 1 Rev 1 no boot

Post by PhilC »

Dwh18 wrote: Wed Mar 26, 2025 8:48 pm Well, almost quitting and leaving this Motherboard and searching for a new one... anyone in EU that repairs Ataris?
If you do decide to give up with that motherboard, then please send it to me, id like to have a look at it and would post the results on the forum.
If it ain't broke, test it to Destruction.
Post Reply

Return to “HARDWARE ISSUES”