2 bombs at boot

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DaRyon
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Joined: Mon Dec 11, 2023 7:46 am

2 bombs at boot

Post by DaRyon »

Hello Exxos
I have a very strange issue,
1° all PSU caps are changed already, I know my PSU & my floppy, my Keypad are good (I exchanged them with another Atari)
2° When everything is connected on the mother board I always have 2 bombs at boot.
3° If I remove the keypad connector, the TOS boot correctly and Desktop is ok except don't detect the Floppy. (Bip Bip .... all time like of a key was press permanently...)
any idea of what to investigate further ?
thanks
David
Steve
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Joined: Fri Sep 15, 2017 11:49 am

Re: --- > MANDATORY FIXES < ---

Post by Steve »

DaRyon wrote: Sun Feb 11, 2024 6:37 pm Hello Exxos
I have a very strange issue,
1° all PSU caps are changed already, I know my PSU & my floppy, my Keypad are good (I exchanged them with another Atari)
2° When everything is connected on the mother board I always have 2 bombs at boot.
3° If I remove the keypad connector, the TOS boot correctly and Desktop is ok except don't detect the Floppy. (Bip Bip .... all time like of a key was press permanently...)
any idea of what to investigate further ?
thanks
David
If you check out these error codes:
https://www.atari-forum.com/viewtopic.php?t=15500

It seems 2 bombs means 'drive not ready'. I would probably focus on mandatory upgrades like: floppy drive pull-up resistors and the DMA pull-ups.
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JezC
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Re: --- > MANDATORY FIXES < ---

Post by JezC »

Just to rule out one possible issue, can you tell us which TOS version you are using?
IIRC TOS 2.x needs a floppy drive connected or it reports 2 bonds at boot anyway
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rubber_jonnie
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Re: --- > MANDATORY FIXES < ---

Post by rubber_jonnie »

DaRyon wrote: Sun Feb 11, 2024 6:37 pm Hello Exxos
I have a very strange issue,
1° all PSU caps are changed already, I know my PSU & my floppy, my Keypad are good (I exchanged them with another Atari)
2° When everything is connected on the mother board I always have 2 bombs at boot.
Always a good start.
DaRyon wrote: Sun Feb 11, 2024 6:37 pm 3° If I remove the keypad connector, the TOS boot correctly and Desktop is ok except don't detect the Floppy. (Bip Bip .... all time like of a key was press permanently...)
any idea of what to investigate further ?
thanks
David
Firstly, you really need to state what machine it is (ST, STF, STFM, STE etc) and what version of TOS so we know what we're dealing with. For example, if TOS 2.06 does not detect an FDD then it will bomb on startup. Usually that's with 4 bombs, so not quite the same, but worth knowing what you're dealing with.

Second, AFAIK with the keyboard removed, STs (Definitely Megas) will behave as though there is a key pressed, so don't worry about that, it just needs a keyboard. Check to be sure the connector cable is correctly oriented, and check both ends of the KBD cable for bad connections.

With regards to the FDD, is there any sign of life from it during boot at all? Is it the original FDD or have you swapped it for a PC drive? PC drives are normally set to ID1, but ST drives require an ID of 0.

I'd check that power is good, as I once had an STFM where the power wires for the FDD had freyed and the GND was touching 5v at the point it connected to the mainboard. You can check with a magnifying glass and multimeter in continuity mode to see if the wire is freyed and shorting.

Also check that the FDD is getting +5v at the plug. You can always double check that the +12V is also present, but it's only usually the older drives that need it. Check it anyway just in case.

Finally, check the FDD data cable is OK and not reversed. If you get a solid on FDD LED then it may be reversed.
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DaRyon
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Re: --- > MANDATORY FIXES < ---

Post by DaRyon »

Hi everyone

thanks a lot for all your feedback
so to answer your points:
I'm not sure about the TOS version since I can't manage to boot it (no desktop)
is there a way to know when the Atari is not booting properly ?
this is a 1040 STF version serial number A17BI4016960M original TOS

For you information, I tried to plug another floppy disk (which I know it works on another 520STE) same 2 bombs popping up

Going to try the pull up fixes ? looks the obvious one isn't?

Best
David
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olivier.jan
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Re: 2 bombs at boot

Post by olivier.jan »

As it’s a 1040 STF, unless you have a special add-on, the TOS version is < 2, so you can safely boot without floppy. What happens if you boot with the keyboard but without the floppy ?
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Smonson
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Re: --- > MANDATORY FIXES < ---

Post by Smonson »

Steve wrote: Mon Feb 12, 2024 10:11 am If you check out these error codes:
https://www.atari-forum.com/viewtopic.php?t=15500
2 bombs is Bus Error. That top list is the GEM error code numbers.

I see 2 bombs a lot because I suck at programming ;)
Steve
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Re: 2 bombs at boot

Post by Steve »

@Smonson AHH thanks I never noticed this :)
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