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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: dougal on February 13, 2012, 02:25:07 PM

Title: Strange guru. Pic attached
Post by: dougal on February 13, 2012, 02:25:07 PM
Whenever my A2000 gets a guru it looks like this. See attached picture.

The A2000 works fine just wondering why it looks like this..

It has an ECS Denise, Kickstart 2.04 and OCS Agnus with 512KB chip mem. No Zorro cards attached.

The 2nd pic is stranger. I used Relokick1.3 and tried loading something which guru'd because of lack of ram. But look at the guru... Strannnge. WHen i left clicked it was back in KS 2.04.
Title: Re: Strange guru. Pic attached
Post by: orcish75 on February 13, 2012, 09:17:00 PM
Hi Dougal,

What revision is your A2000 motherboard? My 6.0 revision board (has a small 74ls373 riser board next to the chipmem) occasionally displayed strange artifacts when I only had 512K chipmem. When I did the motherboard mod to enable all memory as 1MB chipmem, all the artifacts disappeared and worked perfectly.

Artifacts like that usually point to faulty memory or Agnus, but you say yours works perfectly the rest of the time, so this one might be difficult to nail down. Try taking out your Agnus and reseating it or replace your OCS Agnus with an ECS one and try enable the full 1MB as chipmem.

NB: If you do decide to replace the Agnus, just make sure you get one that has the exact same pin-outs as your original one. There are many different versions of Agnuses (Agnii?) that are the same physically, but have different signals on the pins.

Cheers
Title: Re: Strange guru. Pic attached
Post by: Steady on February 14, 2012, 06:05:46 AM
Looks like a runaway copper to me.
Title: Re: Strange guru. Pic attached
Post by: dougal on February 14, 2012, 07:27:40 AM
I tried another 2 Agnus i had in my parts box. One of them the A2000 did not boot, just black screen and with the other it booted but the screen was smaller with black borders top and bottom of screen.
Title: Re: Strange guru. Pic attached
Post by: dougal on February 14, 2012, 07:28:24 AM
The motherboard is Rev 4.0
Title: Re: Strange guru. Pic attached
Post by: AmigaClassicRule on February 14, 2012, 06:25:43 PM
Quote from: dougal;680372
Whenever my A2000 gets a guru it looks like this. See attached picture.
 
The A2000 works fine just wondering why it looks like this..
 
It has an ECS Denise, Kickstart 2.04 and OCS Agnus with 512KB chip mem. No Zorro cards attached.

 
My love to classic Amiga is trippling because of that picture!!! :D :D :D!! It is truly a toy isn't it? :D
Title: Re: Strange guru. Pic attached
Post by: Zac67 on February 14, 2012, 07:37:34 PM
Possibly Chipmem ran pretty low when guruing out...
Title: Re: Strange guru. Pic attached
Post by: Mrs Beanbag on February 14, 2012, 07:58:34 PM
What kind of software are you running when this happens?
Title: Re: Strange guru. Pic attached
Post by: AmigaClassicRule on February 14, 2012, 07:58:58 PM
Quote from: Zac67;680510
Possibly Chipmem ran pretty low when guruing out...

 
:roflmao::lol: :biglaugh: :biglaugh: :biglaugh: :biglaugh:
Title: Re: Strange guru. Pic attached
Post by: dougal on February 14, 2012, 08:01:21 PM
Quote from: Mrs Beanbag;680512
What kind of software are you running when this happens?


Nothing in particular. I was getting the gurus mostly because i did not have a keyboard, so i was rebooting it by turning the Amiga off and on again.

I got a keyboard now :)
Title: Re: Strange guru. Pic attached
Post by: dougal on February 19, 2012, 11:36:49 AM
Updated
Title: Re: Strange guru. Pic attached
Post by: dougal on February 25, 2012, 09:09:15 AM
Solved. It was the Agnus dying. Agnus is now dead... R.I.P

Replaced it with an 8372 and its working fine and no more glitches.