A2000 Power Supply - AT Conversion?

[jiffydos]

Hi All,

Does anyone out there either have an A2000 power supply available, preferably a BigFoot, or know how to convert a PC power supply (AT or ATX) to work in the A2000?

Thanks!

[billt]

Search for a2000t.lha on aminet. Eh, here it is - http://main.aminet.net/hard/hack/A2000T.lha This shows how I conneted my 2000 motherboard to an AT power supply.

[jiffydos]

I was reading that file... and Have my conversion pretty much done.  However, shouldn't the jumper change be j200, not j300?  

[jiffydos]

Nevermind... I looked a bit more... and the information on the net was just wrong, I think.  Some of the pages I found online about A2000 jumpers were different than others.  But, I think I'm all set.

[JimS]

I have a dead bigfoot power supply... when I opend it up to check it out, it appeared to be just a stock pc power supply mounted in an Amiga power supply case - with the addition of a small pcb to generater the 'tick' signal.

There is a circuit on Aminet to generate that signal if you need it. I understand some video boards do.

[jiffydos]

Well... I'm using the stock video.  This is about as stock an A2000 as they come.  I have a GVP HC+8 with 8MB of ram on it and a 4Gig scsi drive.  That's it.  Otherwise, it has 2.04 roms and no other expansion.  

So, you can see why I don't want to spend the cash on a new or replacement PSU.

I have yet to test it, but i believe I am finished modifying my AT PSU to work.  Hopefuly, the stock video will produce the right tick.

[glitch]

Hi,

     I did this years back as I needed a power supply for testing A2000 boards on my bench.  I've still got it and can take a picture of the connector if it would help.  The colour coding of the wires should be generic I'm assuming.  I can't recall what setting I had to have the tick jumper set to in order to get it to work though...

-G

[jiffydos]

Unfortunately, I get nothing right now.    The power light comes on full, but nothing else happens.  The floppy never starts ticking, and the video never comes on.  

I have tried with both the 300 and 200 jumpers changed, no difference.

[Arthic]

Hi Jiffy,

I got the same problem here!

But luckly I have a complete working A500, and I did test all the ICs on it...

The problem was on CIA chip (8520-A1)...check if one of them (the right one) is getting hot. Try to swap it with the left one (they are the same code), and try to boot again. If it shows video, you`ll need a new 8520-A1, otherwise your disk drive won`t work! :-)

I replaced with one 8520-A1 good from my A500. This solved the problem for me. :-P

Be careful with static electricity...These chips are very sensitive!! Use a grounded bracelet and remove the power lead before start working on it.

Good luck!!

All the best

Claudio Raso

[orange]

its  J300, information about jumper for 'tick' signal on Big Book of Amiga hardware is not correct. Better solution would be to make your own tick,  here
(IIRC the clock will be a bit less inaccurate and some genlocks will work)

and here are PCBs in Protel:
link