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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: KatManDEW on February 03, 2009, 02:33:23 AM
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I got the Megachip for my A2000 and installed it, but I had no video display. I reinstalled the original one meg chip, but still no display :boohoo:
It still boots, but no display.
I took a shoe off to ground myself while working on it. I used magnifying glasses and checked all the pins on the chip and in the socket and they all look OK.
Am I hosed?
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Can we assume you put Agnes back in the proper way, observing the notch?
Those pins are REALLY easy to misalign if so. Might be a good idea to triple check both the socket for foreign matter (sliver of plastic) and Agnes herself...
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I cleaned the chip and socket pins with some wizz bang, super duper contact cleaner that I got off the net, and my display is back!
But I lost DH0 in the process. It wouldn't boot from hard drive, so I booted from floppy, and DH1 is still there, but no DH0.
Funny thing is, that with the Megachip in there, it says I only have 437,592 chip mem, and 18,543,528 other mem. I had 885,720 chip mem before, and I only have 16 meg on my GVP 040 card....
But I just added 12 meg to the GVP card, so maybe that's screwing with my chip mem?
Edit: This megachip board I got doesn't have a jumper wire hanging off it, like I've seen on other megachip boards???
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Also the remove and reinsertion of Denise can help.
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Did your motherboard require some jumper changes to accept that megachip board?
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We need your motherboard version...
All is explained here:
http://amiga.resource.cx/manual/MegAChip.pdf
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Gilloo wrote:
We need your motherboard version...
All is explained here:
http://amiga.resource.cx/manual/MegAChip.pdf
Ahh Haa! That is exactly what I needed. I'll will check that out this evening.
Thank you very much!
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Yep - there is a jumper you need to change. Goes from 512mb Chip to 1mb. Only when it is in the "full" 1mb mode, will the mobo see 2mb with the MegaChip. Also, the lead from the MegaChip usually goes to pin 36 on Gary. Yours may have broken off. Not sure if there was a DKB model that did NOT have that croc clip. But look for an obvious "hole" or place where that black lead may have originated from...
Maybe post a pic here of it too if you're still having probs...
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I remember replacing the 512k Agnus with a 1 mb Agnus, many many years ago.
My Megachip board does not have a black lead with a croc clip, like the ones I've seen in pics. I'll get a pic of mine and post it tonight.
Is there a way to post pics here on Amiga.org? I've been putting them on my website and linking to them here on Amiga.org.
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Here's a pic of my Megachip board. It has two holes in the back of the board.
(http://www.katmandew.com/images/Misc/Amiga%202000%20Megachip.jpg)
I've gotta dig around and find my motherboard revision...
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I found the revision number on my motherboard. It's revision 4.4.
I read that Megachip PDF several times, and I don't see any way mine is going to work without the black jumper, which is noticably missing from my Megachip.
Does anyone know what I can do about this?
Mine doesn't looks axactly the same as the DKB Megachip shown on the Big Book of Amiga Hardware
This is the DKB version;
(http://www.amiga-hardware.com/display_photos/megachip_1_sm.jpg)
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Yours is a MegiChip.
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zipper wrote:
Yours is a MegiChip.
OK. That makes sense, kinda... According to the Amiga Ahrdware Guide info, it should have two wires that go to a socket for the Gary chip.
http://www.amiga-hardware.com/showhardware.cgi?HARDID=985
I got it from SoftHut, and it came with no wires or socket :boohoo:
Thanks for the info.
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Yours is probably an earlier version than the pictured v2.1 - suppose the connections are the same still.