A3000 help please

[Noster]

Hi

@graffias79

I would take a magnifying glass and have a closer look at the pins of the RAM-chips. I've bought a used A3000T, and if I had a look at the RAM's of the chip-RAM (the A3000T uses ZIP-RAMs for both chip and fast-ram) I found two chips, where the pins where bent and doesn't stick in the sockets. Nevertheless the system was running (?!) without an obvious fault, but maybe your problem is the result of such a misplaced chip ?

Noster

[graffias79]

Ok just for S&G I transplanted a standard OCS Denise chip into the A3000.  For all practical purposes it worked just fine, except no ECS modes (of course).  Unfortunately the machine is still flaky.  It seems to bring out the worst in HAM mode.  I checked the PAL chips, neither seemed very warm, the chipram is soldered on to the motherboard (theres an equal ammount of unpopulated dip sockets next to it I assume for 1 more MB of chipram).  I'm begining to suspect the power supply at this point. :-(  Oh well  Thanks for all the help anyway.

[drwho]

graffias79 wrote:

Mine has a green LED but strangely the HDD LED never lights up.  The little PCB on which the LEDs exist does not look damaged or cracked either, just slightly flexed where it's screwed in.  

>> These LEDs die constantly. My power LED on my A3000D has been dead for eons, yet my HD LED works great.

 I don't think its the scandoubler at all since on DPaint, if the video corruption occurs on the screen it becomes part of the picture.  I can select and stamp the glitches as if I drew them myself which is what makes me suspect chipram.

Could be chip mem, also, I may be mistaken, doesn't the Agnus handle graphics operations? If it's not the chip memory, could the Agnus be at fault?

I would still like to try my OCS Denise, but I don't want to cook anything!

I have a set of chips from what I believe is an A500 ECS system that I pulled just recently. I don't know if they are the same as those used in the A3000 but, I would be willing to drop them in the mail to you if you need them. I have a Denise, Gary, Paula, both CIA's.

Is there a way to tell if the chips are ECS or not?

Thanks,
Mike

[Ilwrath]

Is there a way to tell if the chips are ECS or not?

But of course....

8362 is an OCS Denise
    R5=A1000 R6-8=A500/2000/CDTV
8373 is an ECS Denise
    R3=A500+/A3000 R4=A500+/A600

(I believe an 8373 R4 should also work in an A3000 with no problem, as they both work in the A500+...)

Source: vgr.com's Amiga chip directory

Gary looks to be incompatible between the A500 and A3000, as also, I believe the CIAs might be (they're not listed in VGR.com, though.)