Another A4000 in need of help

Hello all :-)

I received another A4000 motherboard from EBay today.
It didn't cost very much so I thought I would take a chance.
As expected the board does not work (was sold as unknown) :-(
When plugged in all I get is a black screen no caps light flash or anything, at least my tv recognises it at 50hz PAL.

The board looks like it has been re caped as it has lots of small square caps in place of the more normal cylinder shaped ones.
It has also had the battery removed before it caused any damage however there is a small component soldered between D178 and the Ricoh RTC chip (see images) which I am unsure about.
Some of the jumpers at J100 where set to an external clock before I set them back to the same as my working A4000 EC030 (thanks hikey).
The main area of concern is under the kickstart chips. I have looked with a magnifying glass and a couple of tracks have been fixed with a strand of wire.
The kickstart chips are v3.0 but do not look like my original v3.0 ones.
There is also some strange cap soldering around C317 which i am unsure about.
Last but not leased I have spotted an extra wire near the audio outputs (see pictures)

Any help would be great as I do not want to bin the board.
I would much rather getting it fixed / swapped.

Thanks in advance

James

Can't tell you about the caps much, i s'pose if the ratings are correct, no harm is done... As about the ROMs they're pretty original allright!
Now, the diode soldered to the rtc, i've seen it before, and am almost certain it's there by default. Someone more experienced will certainly tell you much more :thumbsup:

Looks like someone have gotten close and personal with their soldering iron on the red plastic in the last pic.

zzz

I think this is the same revision as your motherboard, maybe it will help with checking the capacitors and the component near the rtc.

http://www.amiga-hardware.com/downlo...00revbmb_1.jpg

Also the roms look authentic to me. Both of my A1200s had roms like the "MX" one in your picture.

Cosmos

• With memory in (or out) the screen remains black, it does exactly the same even with out fitting the cpu board

salaxi54
dwayneh

• My original roms before getting some 3.1 both have the MX logo, is it common to have miss matched looking roms?

moijk

• Yer I know what you mean but not me this time round (I melted the edge of a simm slot before hikey replaced them all for me, different board mind)

Quote:

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Originally Posted by Bastich

[*] My original roms before getting some 3.1 both have the MX logo, is it common to have miss matched looking roms?

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The 3.0 roms I changed in my A1200D were exactly the same as yours, mismatched.. I changed the roms in my A1200T about 10 years ago now, so I can't remember what they looked like.

Just a quick thought.
Will the system boot without the daughter board?
I did not connect it as I didn't want to dismantle my working A4000.

Yes it will boot without a daughterboard.

Have you verified the ROM chips you got on the 4000 board are indeed 4000 rom chips?

I remember reading somewhere that amiga 1200 Rom chips do not work on a4000 boards. Sometimes buying boards from an unknown source, becomes hard to troubleshoot, because you don't ever know what the previous owner has done.

I'm wondering perhaps if they (unknowingly off course!) installed a 1200 rom in the 4000 board before selling it to you..............