TT030 black screen of death

[ajar75]

Hi all, so I wanted to do my due diligence before coming back and asking for help.
I have an older style PGA daughter card on my motherboard. I have a TT Test Cart 1.4 inserted. I still get no video via vga output.

1) I've verified 32Mhz clock on J100 (which seems to be the pin the Oscillator comes in on (brown wire))
2) I've verified 32Mhz on a test point on the PGA daughter card. Perhaps this is pin 6, dunno. CLK pin is high
3) I've verified 16, 4, and 2Mhz clocks on my TTVideo card as an aside
4) I get nothing via rs232 using a null model adapter
5) I'm not sure I'm checking the right pins is my main problem, but STATUS according to the 68030 pins is low.
6) HALT, BERR, STERM DSACK0,1 are high.
7) STATUS is low.
8) Reset pin goes low and high when i press the reset button (which is in pristine condition).
9) I've replaced, realtime clock chip top right (and got a new battery), replaced the floppy controller with AJAX (because why not), replaced DMA, replaced both MFPs
10) I've taken the motherboard out and inspected underside and top, no obvious signs of corrosion or anything.

Thoughts and strategies from the experts here on where to next? Any help would be much appreciated.

[frank.lukas]

See the schematics, there is a SMD 74F244 IC that driven some 16Mhz System clocks. Check it ...

[rubber_jonnie]

Have you checked that power is good? That should be one of the first things to rule out.

[ajar75]

I'll ask the ignorant question, i've seen people talking about testing the power good signal or something, but I'm not sure how to do that? other than that, the PS seems to be good, it's driving a Zulu SCSI and the Gotek just fine. i replaced the fan with a noctua, etc. The green light comes on.

Thank you!

[frank.lukas]

... If the 5 volt voltage is between 4.9 and 5.1 volts, everything is fine. Powergood is also just under 5 volts. The Atari power supplies are very good and a little ripple doesn't matter.

If the Powergood signal not high the CPU do not work, see the schematics ...

[ajar75]

Ok, I did test 5v power through the floppy disk 5v pin (red wire) and it is outputting at a solid, and unwavering 5.2 ish volts. so I don't think it is a power supply issue...