Problem hooking up MiniMegi chip in A2000

[barney]

Does anybody know what could be causing a MiniMegi chip not to work.  I install the chip in the agnus slot.  I insert the Gary chip in the slot riser and insert the riser in the Gary slot.  After all this, the computer looks to booting up according to HDD Led but no video is output to my monitor.  I have my monitor hooked up to the Indivision ECS scandoubler.  Is there some kind of incompatibility with this scan doubler and the MiniMegi chip or is there some other problem I may be having.  Thanks.

Barney

[save2600]

did you try hooking the composite output to a monitor to see that the computer did indeed boot?

That riser for Gary... you're sure that's installed correctly as per the notch? hehe

[barney]

I could try hooking up my 1080 to see if it is correctly booting.  One more question.  Do you or anybody else know of a screen shot that I could look at showing a correctly hooked up DCE Minimegi chip and gary adapter.  This would verify whether I have everything turned the correct way.  Thanks.

[save2600]

I just know that the lead coming off the Agnus board goes to pin 36 of Gary. But the notches on the socket (riser) should reflect that. Ensure the notch of the socket matches the notch of Gary. AND that ALL of the pins on that socket are in Gary's socket.

[barney]

I attempted to boot it up one more try and for some reason it worked this one time.  After that, every time I boot up, my screen flashes green.  The hard drive doesn't load the OS, the screen just continues to flash green.  Does anybody know what a flashing green screen means?

[barney]

UPdate:  I did a google search and found that a flashing green screen on bootup means there is an error in chip ram.  Now what do I do?

[save2600]

http://greenlanternmovie.warnerbros.com/

Just kidding!

Green flashes (normal if you have a Deneb USB card) indicate bad Chip RAM or... bad Agnus! Pull the old girl out and ensure all her tiny little pins are aligned and that your MiniMega Chip board is fully inserted. Really, really easy to accidentally bend those puppies removing her though, so no surprise there. Hopefully you have a nice PLCC puller and are not prying her out with tiny screwdrivers - ouch!

[barney]

I can't pull the Agnes out.  I bought the version from Amigakit that has an Agnes chip already soldered into the MiniMegi board itself.  I removed my old chip and dropped this entire unit in its place.  Is there some compatibility with the chip Amigakit uses and my motherboard?

[VingtTrois]

Is this AGNUS has already worked properly at least once?
What's the revision of AGNUS (PAL/NTSC)?

[barney]

Ok, final update:  It now works.  I gave a few good pushes on the MiniMegi board and I think that may have completely seated it.  I think I may have slightly deformed the motherboard socket pins and the MiniMegi may not be sitting in there as snug as it should be.  I think it may actually be "floating in the socket" if you know what I mean.  I am going to open it up and re-straighten or re-align the pins on the motherboard to grab the chip better.  Thanks for everybodies help.

I have one small question.  Out of curiosity, what would happen if sombody were to remove their regular agnus from their A2000 and install the Agnus from the A3000?  Would that work, or would it crash the machine?  Thanks.

[save2600]

You can't use an 8375 or 8372AB Agnus in an A2000 without purchasing a board like you already have. I don't think the machine even boots with it installed. I gave it a try once and IIRC, that's what happened - nothing. Thankfully I didn't blow my mobo. lol

[Gilloo]

green screen at boot => agnus is not seated correctly (if the chip ram is bad... too bad)
you can use an eraser gum (white Staetdler for example) to clean the contacts and a brush to remove the gum parings.
The top of agnus should be at the right of the motherboard, if the letters are in the good way, and the the 68000 in front.

[alexh]

Out of curiosity, what would happen if somebody were to remove their regular agnus from their A2000 and install the Agnus from the A3000?  Would that work, or would it crash the machine?  Thanks.

It would not work.

FYI there is a slim chance doing so might even break the motherboard and/or the Agnus chip as the pinout of the two chips is different, if power and ground are switched then bang, magic smoke.

[Zac67]

Ain't that bad (ie. shouldn't break anything) but since it can't work I wouldn't bother trying.

[Fingers]

I think it may actually be "floating in the socket" if you know what I mean.

These sockets often get cracked in A2000s.

If you look & find a crack, the easy (lazy) fix is to wrap a thin cable tie around the outside of it before installing the chip/expansion

PZ.