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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: McVenco on January 10, 2008, 04:32:18 PM

Title: A4000 starting troubles
Post by: McVenco on January 10, 2008, 04:32:18 PM

Another one of my miggies having startup hiccups:

I've got an A4000/040 which just won't boot. I tried switching all parts (except the mainboard) with my other - working - A4000/040 but to no avail. Jumper settings are all the same so I expect it to be something on the mainboard.

When I turn on the machine I get nothing but a grey screen. Just the semi-darkish grey you get when an Amiga normally boots. The power LED comes on but stays dim (not bright as it should be) and the keyboard LED blinks once.

Any idea? Anyone? Anyone?

Title: Re: A4000 starting troubles
Post by: Matt_H on January 10, 2008, 04:56:50 PM

Using a 3640? I sometimes got this behavior before I had a missing capacitor replaced and the others corrected.

Otherwise, keep pressing down on the Fast Slot connection. If something works itself loose, it sometimes takes me a dozen attempts to get it corrected.

Title: Re: A4000 starting troubles
Post by: rkauer on January 10, 2008, 07:05:34 PM

 Bad PSU or the PSU connector on the motherboard is stained or just dirty.

Title: Re: A4000 starting troubles
Post by: McVenco on January 11, 2008, 11:19:43 AM

Well, the problem somehow solved itself. After I replaced all original parts (and cleaned them of any dirt) it still didn't work. I took it apart again, reseated all socketed things, even removed and returned the 2 clock crystals and hey presto! It works!

No idea what the problem was, but it seems solved. Weird stuff, these computer things.... :-)

Title: Re: A4000 starting troubles
Post by: tokyoracer on January 11, 2008, 01:26:51 PM

Well done! :-) Computers are odd things at times, I have experianced similar with a CD32 (switching on and off and then it suddenly burst into life). Other experiances are with Win Boxe$, obviously. :lol:

Title: Re: A4000 starting troubles
Post by: rkauer on January 11, 2008, 10:09:43 PM

Quote

tokyoracer wrote:
Well done! :-) Computers are odd things at times, I have experianced similar with a CD32 (switching on and off and then it suddenly burst into life). Other experiances are with Win Boxe$, obviously. :lol:

 Bad caps on the CD32 board!

 When the caps are dried inside the results is the behavior you describe.

Title: Re: A4000 starting troubles
Post by: scuzzb494 on January 11, 2008, 11:01:50 PM

Hi

You often get that when the processor board isn't seated along its full length or just badly inserted. It really does have to be inserted cleanly and properly. Also those support pegs are so important. I had great problems with this on the D and the T.

scuzz
http://www.commodore-amiga-retro.com

Title: Re: A4000 starting troubles
Post by: McVenco on January 12, 2008, 06:00:15 PM

Even with the support pegs the problem occured. Maybe it's just bad or dirty contacts. Now where did I put my cleaning alcohol?