4000T problems, wierd video output

I'm still working on my 4000T, trying to get it to work. Today I tried a second A3640 card, to make sure the processor module wasn't the problem. It isn't; the behavior is the same with both cards. I've tried jumping the pins on the keylock connector on the motherboard to no avail; it makes no difference whether the pins are open, or if one or both of the pairs is closed. Out of frustration, I decided to try without the scsi board plugged in, and instead of the blank screen I have been getting, I got a flashing pink bar at the bottom of the screen. Is this normal behavior with the disk module unplugged? Anyone have any thoughts on how to test that the disk and video modules work without buying spares?

[Jose]

The A4000T doesn't boot without the disks module, at least the one I have and I've seen this confirmed by others various times.
Have you set up the jumpers on the motherboard correctly ? IIRC the system clock can't be set to EXT (or something) with a 3640.

yeah, I was just hoping to see something other than a blank screen.  :madashell:  I don't know; I have all the jumpers set up correctly and it just doesn't want to boot. I'm starting to think the mb or one of the modules is doa.

[Jeff]

How long have you waited for a boot screen? Was it always this way or did you just buy it?

I have an A4000T that waits so long to boot I thought it was DOA for days until I forgot I left it on. I bought it that way. The original owner solved the problem by installing A4000D (Desktop without the NCR SCSI driver) Kickstart ROMS in the machine and sold it that way to me. The first thing I did was put the correct 40.70 (T) ROMS back in and I created the problem. I put the old 40.68 desktop ones back in and left it. It still works to this day and infact is running OS4 right now with a CSPPC.

Good Luck,
-Jeff

I just bought it a couple of weeks ago, and haven't ever gotten it to boot. The longest I've waited after powering it on would be about 35 seconds, I guess.

[Jeff]

Try waiting for a good 5 or 10 minutes for a boot prompt each time you make a configuration change and let us know what happens.

-Jeff

[rkauer]

 Maybe a naive suggestion, but can you leave the Amiga powered on for, said, 4 hours?

 If the a partition are re-validating, the screen stays black until the validating process is done.

[Jose]

You should wait more than 35 seconds, the 4000T waits more time because it also waits on the scsi bus. Cant' remember the exact wait time but with nothing attached to the motherboard, only CPU card (how you should start to detect problems) (and disks/audio video module in the case of the 4000T of course) it was surely more than 35 seconds.
Give it a try and wait 5 minutes.

So, it's been a while, but I've finally gotten back to my 4000T project. I got a new set of disk and video modules for it, and plugged them in, and started the system up. Video display was green noise for a moment, and then black. Subsequent attempts to boot result in a black screen. I've left the system running for about 15 minutes now, and still just a blank screen. Any thoughts?

[Vlabguy1]

I have some thoughts..

First what gfx card if any..do you have installed?
Also you might want to check the capacitors on the audio/video module..as well as the ports module..

If all is fine there..then check the caps on the MB.

Rich
ny

I don't have a graphics card installed, I'm using an A520 to convert the RGB output to composite video.

I've given the boards a visual inspection, there's nothing visibly wrong with the motherboard, or with either set of the video and disk modules, and the ports module doesn't show any signs of damage either.

[Kristian95]

green screen could be chip-mem problem but then it should show up every time you boot... my best guess is that one of the custom chips might not be too happy... as to which one... I wish I could tell you (all guesses here but maybe I spark an idea with you or someone else to help you get this puppy up and running again)

[yogisumo]

have you tried booting with a barebones, stock boot floppy?
Maybe the monitor prefs are set to a resolution that the a520 can't handle? Or maybe you have drivers for a gfx card?

[amesie2]

@pkillo

I once had a 4000T that was experencing a boot problem where you would turn the system on and it would just sit there until I would do a warm reset ctrl+LA+RA keys and then it would boot normally.
This would happen each time from a cold boot.

Good luck with your problem!

[matthey]

Hold both mouse buttons when you turn it on or reboot and see if you get the early startup boot menu. If you do, then your problem is minor. Make sure the ribbon cables going to the I/O board are not misaligned by a pin. You may need a flashlight to see. Try a different power supply. It's just a standard AT power supply and it's easy to swap. I just swapped mine out and it solved random crashes and periodic reboots I was having.