Filled A3640 Repair/upgrade

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wizzard_o

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Hi everyone,
I have a Dead Rev 3.1 A3640 i bought here a few months ago, it arrived DOA and i'm having no luck in contacting the seller. I set Both J100 jumpers to ext but my 4000 fails to boot up with the card, it works fine with the '030 board installed.

Anyway, it has a 33Mhz '040, is supposed to be patched to 3.2 spec with some of the waitestates removed, some of the GAL/PAL's are in sockets and for some reason. Whats really worrying me is that U203 has a bare wire sticking out, I removed the GAL and it seems to be soldered onto the socket?

FullSizeRender.jpgIMG_0142.jpg

Any ideas anyone?

Thanks,

Wizz.
 
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fitzsteve

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The modification is to run at 33mhz. If that has come loose you might need to solder it back. Drop in a 50mhz oscillator and see if it runs at stock 25mhz
 
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tbtorro

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A3640 Repair/upgrade

The PCB around U203 looks overheated, who knows what's the state of the pads underneath the chip. The pad could be missing (burned off) underneath that particular pin and the wire is (was) probably a jump wire and should be soldered somewhere at both ends.

But of course this is just a guess without actual diagnosis.
 
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wizzard_o

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Hi,
It does not work with a 50Mhz clock, I think he's dead Jim :(

Is there anyone around who can diagnose and repair this?
 

Sardine

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sent the original seller "napolalf" a PM with questions.
 

wizzard_o

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Replied to bebek's PM

In all fairness the seller did contact me yesterday, however as he lives in Canada there's not much he can do. So it's going to be repaired.
 

wizzard_o

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Bebek has worked his magic again, the A3640 works like a charm and is rock steady clocked at 33 Mhz.

I do have a question though, is there any additional software I need to install for this CPU card and do I need to set the maprom jumper when i'm using 3.9 with the ROM updates?

Thanks!
 
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