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Author Topic: A4000 motherboard-getting there  (Read 6408 times)

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Offline gary2000Topic starter

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A4000 motherboard-getting there
« on: June 14, 2019, 02:48:11 PM »
It's coming along...
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #1 on: June 16, 2019, 09:09:19 PM »
Thank you. I'm sure I will have questions.

Yes, that placement tool works well!
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #2 on: June 29, 2019, 07:55:29 PM »
Would anybody know what the part number is for the 6 pin power connector? I bought amp 350711-1, which looks to be correct, but has male contacts instead of female.
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #3 on: June 30, 2019, 10:31:50 PM »
Thanks !
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #4 on: September 07, 2019, 06:43:53 PM »
First test result is a black screen , with video sync and no serial output to diagrom . Clocks look okay and voltages are fine , except -12 measures -11.13

Should sclk on Lisa be 3.571 MHz?

Should ECLK on U300 CIA be 714 KHz?

kbrst is always held low .  Should this go high on reboot?

 Seems to be no activity on Paula, Gary , Alice address lines

 This seems to be a global issue keeping the system down .

 Any other basic items I should check ? I'm trying to be methodical, but find myself stabbing in the dark .




« Last Edit: September 13, 2019, 10:47:45 PM by gary2000 »
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #5 on: September 15, 2019, 04:50:28 PM »
It's working!

 Fail pin was pulled low by power supply PG brown/ gray cable, so Gary would not reset . In Skynet power supply , IC7 I suspect is bad . I got impatient, and just cut the wire and ran to five volts.

 Diagrom checksum test okay, CPU and chip ram is seen .

 Hangs on fast ram check . But, that's progress .
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #6 on: September 17, 2019, 01:40:18 PM »
Thanks Acill!  You and Chucky have saved the Amiga hardware community.

 Absolutely !
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #7 on: October 07, 2019, 01:35:01 AM »
Well, moving along smoothly until I inserted the Zorro daughterboard. The computer will boot one out of 10 times with errors if the daughterboard is in place . It works flawlessly without it , so far with diagrom. Will not boot with original ROMs , though.

 Anybody have a similar issue ? So far, checking u701/U714 pals , buster  and the CPU are involved as well.

 Will not be very expandable at this point , weird .
« Last Edit: October 13, 2019, 01:56:09 PM by gary2000 »
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #8 on: January 11, 2020, 01:00:21 AM »
Just to update:
Replaced PAL U714 which corrected zorro II problem.
With diagrom, CPU okay, chip RAM tested okay, fast RAM ok, all video and audio tests okay, IRQ/CIA okay, zorro II detected ram card, IDE detected correctly, floppy drive seen.
With 3.0 roms will not boot, resets, and then stops after screen turns on. 
OVL = L with diagrom and H with 3.0 rom, is that normal?

Anyone have any other suggestions to check for?

Are 3.1 roms available for download to burn for me to purchase? I do not want 3.1.4 at this time.
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #9 on: January 16, 2020, 09:32:04 PM »
I have nothing against 3.1.4, I only wanted 3.1 to test with. (Have enough unknown variables to deal with).
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #10 on: February 03, 2020, 12:01:04 AM »
The only issue I had with running diagrom was a vertical hold problem rolling screen.

Could someone tell me the in-circuit value of R514, which shows 10K? Mine is 3K or 4.5K without resistor, and this does not seem normal.
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #11 on: February 16, 2020, 01:07:35 AM »
Well, it finally booted to Kick start screen!

The Commodore roms went bad, which was surprising.

One issue other than the occasional yellow screen, is when you put in a disk OVL is held high. You must turn off and turn on again for the high to low to happen. Has anyone seen this happen?

Most games will not fully load and there is graphical corruption when trying, but work bench will load fine.
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #12 on: March 19, 2020, 11:35:08 PM »
Mostly working at this point, but I have the following issues:   

When selecting from Gotek, you have to manually turn off the power and turn on to reboot instead of warm restart.

Fast RAM 4MB shows as 1 - I believe this has to do with the power supply _fail + 5 V as shown in other posts.

Only Gotek works as DF0 and original floppy is unstable and does not load much. All jumpers were set correctly.

Sysinfo reports and ECS Agnus instead of Alice AGA. It also shows 25 mhz as 030, even though it is an 040.  It sometimes reports as 16 mhz, also using Sysinfo 4.3.

Some games work perfectly and some crash. Workbench loads ok.  Any ideas on these issues?
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #13 on: March 21, 2020, 02:25:54 AM »
Ok, thanks. I will check into that.
 

Offline gary2000Topic starter

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Re: A4000 motherboard-getting there
« Reply #14 on: March 22, 2020, 11:55:51 PM »
Ended up installing bestWB.  Showconfig looked ok / 256 colors working.

Sysinfo still showing ECS Agnus - 2 / 68040 16.60 with IDE drive attached and 25.60 with no hard drive.

Checked and replaced gals for IDE, no difference. I wonder if the MMULIB is the one included in bestWB. In startup-sequence it says CPU checkinstall. Hopefully this is just a configuration issue.