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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: NECROSCOPE on November 16, 2005, 03:32:03 PM

Title: A4000 CPU, from 030 to 040
Post by: NECROSCOPE on November 16, 2005, 03:32:03 PM

I got a new 040/25 and will try to change it on my old, dead, CPU board. Can you confirm the position of the jumpers for the clock, int ext?!?! They are both from Commodore. THANKS!

Title: Re: A4000 CPU, from 030 to 040
Post by: Tahoe on November 17, 2005, 07:36:18 AM

For the A3200 card (63030) the jumpers are set for INT
For the A3640 card (68040) the jumpers are set for EXT

Title: Re: A4000 CPU, from 030 to 040
Post by: NECROSCOPE on December 18, 2005, 03:42:15 PM

Well, changed the cpu but the board still dead. Try to look for a info on the foruns for a 3640 repair but didn't found anything. I remember there are some capacitor that go bad on the v3.0. Can sommeone help? Thanks!

Title: Re: A4000 CPU, from 030 to 040
Post by: DaBest on December 18, 2005, 04:11:18 PM

Is your 030 still working ??????
Try re-seating it in the slot.
What color of screen do you get ....if you get any ???

Title: Re: A4000 CPU, from 030 to 040
Post by: rockape on December 18, 2005, 04:44:43 PM

Hi,

From my Help Disk, no source of document.

I did post this article recently :)


"Rev 3640 board V3.0.

This revision will not work in A3000's at all (unknown if this also applies to the A3000T and A4000T) because of a conflict with the DMA handling of the onboard SCSI controller and some Zorro cards.

Although it will work with A4000's. A bug in the design allows the board to grant DMA access to more than one device, causing the machine to hang.

There is also a problem with the STERM* signal that can cause sporadic crashes with some cards such as the Cybervison 64. The PAL or GAL chip located at U209 should be -01.

The A3640 was used as the standard processor card in A3000T's, A4000T's and A4000's shipped with 040's. There are three revisions of this card in common use.

The A3640 does not have provision for installing memory directly onto the accelerator, however a 3rd party product called the X-Calibur provided this feature.

At least some A3640s suffer from a serious bug that can drastically reduce the life of the accelerator.

Three capacitors on the board were soldered in the reverse position which can cause them to leak electrolyte over a period of time. These capacitors are labelled C105, C106 and C107. You can verify this by locating position U103, just below the oscillator. Vcc (5V) and G(nd) should be printed on the device.

Check using an ohm meter for a connection between VCC and the black side of the capactors, similarly check for a connection from G to the other side of the capacitors."


Regards, Michael

aka rockape

Title: Re: A4000 CPU, from 030 to 040
Post by: patrik on December 18, 2005, 04:57:28 PM

@NECROSCOPE:

Yeah, three capacitors are mounted the wrong way from the factory, check this (http://joj.home.texas.net/amiga/amiga00.html) page.


/Patrik

Title: Re: A4000 CPU, from 030 to 040
Post by: NECROSCOPE on December 18, 2005, 05:08:53 PM

Works with the 030 cpu board, with the 040 nothing, black screen no boot...

Title: Re: A4000 CPU, from 030 to 040
Post by: Framiga on December 18, 2005, 05:41:25 PM

have you installed the 68040.library in SYS:LIbs/ ?

Title: Re: A4000 CPU, from 030 to 040
Post by: NECROSCOPE on December 18, 2005, 06:25:17 PM

Quote

Framiga wrote:
have you installed the 68040.library in SYS:LIbs/ ?

Oh dear...
From time to time i return to the 4000, i use my trusty 3000 for everything, and try to install the 4040 apollo. I'll check, maybe i left the 040 libs of apollo there instead of the commodore. Don't remember. Maybe... But shouldn't be, it does not sound as it's going thru the startup on the disk, it sound more as there is an hardware problem and it just freeze there...
THANKS ALL FOR YOUR HINTS!