Hello,
I got A2000 after baterry lekage. I replaced CPU socket, ROM socket,RTC chip, fixed 2 traces near CPU. Amiga works now, but only 0,5MB chip is visible in DIAGROM or AmigaTestKit(no slow ram/other ram). J101 on position 1-2, J102-closed, J500-closed.
I swaped Agnus to 8372A(was 8371). J101 on position 2-3, J102-open, J500-open. Still only 0,5MB chip is visible. No other ram.
I have tested U540,U541,U103,U104,U105,U106,U900,U603 on my TL866 programer. All ok.
I swaped chips from A500 (2xCIA,PAULA,DENISE,AGNUS,GARY,CPU). No change
Amiga works. I have installed TF536 on it and started Frontier and Setllers form SD card. Works fine.
Why i can`t get 1MB CHIP or 0,5MB CHIP+ 0,5MB SLOW?
EDIT:
Forgot to say, that i tested with KICK1.3, Kick3.1
Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
Moderators: terriblefire, Terriblefire Moderator
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Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
That should work.
First question, did you have 0,5 MB chip and 0,5MB fast (ranger) ram to start with?
If yes, then please post closeups of the jumper areas
Make sure to measure the cuts you made to the jumper pads.
Have a look at this for the correct changes:
https://www.nightfallcrew.com/30/09/201 ... m-upgrade/
Only the 68000, Gary, Agnus and the ram are involved, changing anythig else is futile IMHO.
p.s. those are Sanyo LM33256G-15 chips?
(please look at them closely)
First question, did you have 0,5 MB chip and 0,5MB fast (ranger) ram to start with?
If yes, then please post closeups of the jumper areas
Make sure to measure the cuts you made to the jumper pads.
Have a look at this for the correct changes:
https://www.nightfallcrew.com/30/09/201 ... m-upgrade/
Only the 68000, Gary, Agnus and the ram are involved, changing anythig else is futile IMHO.
p.s. those are Sanyo LM33256G-15 chips?
(please look at them closely)
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- Posts: 19
- Joined: Wed Jun 03, 2020 9:57 am
Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
Thank You for replay.
I have the same board revision as on this movie and there is a ranger RAM visible and 1MB of chip after mod.
I can se only 0,5MB of chip. Before the mod and after.
I checked the jumper pads with multimeter after cutting and they are separated.
I traced J500 to GARY and after cutting _EXRAM is +5v. 0V if bridged so it works correctly
Memory chips are SANYO LM33256G-15
Someone has schematic for REV 4.3? I found only one for REV6 and there RAM is in different chips.
How Ram is Detected on AMIGA 2000? Maybe some traces are still bad and preventing detection of other 512KB?
I have the same board revision as on this movie and there is a ranger RAM visible and 1MB of chip after mod.
I can se only 0,5MB of chip. Before the mod and after.
I checked the jumper pads with multimeter after cutting and they are separated.
I traced J500 to GARY and after cutting _EXRAM is +5v. 0V if bridged so it works correctly
Memory chips are SANYO LM33256G-15
Someone has schematic for REV 4.3? I found only one for REV6 and there RAM is in different chips.
How Ram is Detected on AMIGA 2000? Maybe some traces are still bad and preventing detection of other 512KB?
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- Posts: 290
- Joined: Thu Feb 28, 2019 5:02 pm
Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
Take a look at this one for the schema:
http://tele-work.hu/Vas/Amiga%20500%20T ... erence.pdf
http://tele-work.hu/Vas/Amiga%20500%20T ... erence.pdf
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- Joined: Wed Jun 03, 2020 9:57 am
Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
One of the RAM chips was bad.
after replacing it, 1MB chip is visible and no errors in memory test.
Thx for help.
after replacing it, 1MB chip is visible and no errors in memory test.
Thx for help.
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- Joined: Thu Feb 28, 2019 5:02 pm
Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
Nice find!
Thanks for letting us know
Thanks for letting us know
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- Joined: Wed Jun 05, 2019 6:41 am
Re: Amiga 2000 Rev 4.3 - Only 0,5MB ram visible (0MB other RAM)
I would advise you to replace the CPU socket if not done already. The gunk goes under the socket. This is a common pb on A2000 that had battery leakage.