A4000 just did something scary

[motorollin]

Just booted my A4000 for the first time in a while and it did something weird. Shortly after powering on (during boot) my hard disk spun down partially and then back up, and the Amiga rebooted.

Then while it was booting it hung with a black screen, and then I noticed that the power light for the A4000 had gone off, even though the hard disk was still spinning! So it seems that the motherboard lost power but the drives didn't.

I powered the whole machine off and back on again, and it booted and is now running perfectly. But I'm a bit concerned about what might have happened. I have re-seated the power connector on the motherboard. But I'm wondering if anyone else has experienced these symptoms and can shed any light on what might have caused it and whether I should be worried.

[EDIT]
+ paragraphs ;-)
[/EDIT]

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moto

[amiga92570]

Maybe it had a minor stroke. :-?  :lol:

[A1260]

check for battery leak, check for dust, check that all cards are sitting good in their sockets, check power cabel, check your old psu....

[HammerD]

@ motorollin

Maybe there was a slight brown-out? Power hiccup? Or potential power supply beginning to fail? (I hope not!)

[yetihw]

I did often with my a2000, I degraded my accelerator and got rid of my graphics card.  It was some sort of card conflict. With Commodore made cards I have had no problems since just a  lack luster amiga I'm afraid but she still works.

[motorollin]

Thanks for all suggestions!

@A1260
The battery has already been removed. Will give it a good cleanout and remove and replace all the cards.

@HammerD
I have replaced the A4000 PSU with a Micro-ATX one, so unless the relatively new PSU is starting to die, I don't think that was the problem.

@yetihw
I have been using the same configuration for ages now and it has been stable. I think it might be something to do with the CV64 since the point at which it fails during boot is when the CGX screen should open. So I'll try re-seating everything and report back!

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moto

[amiga92570]

A4000 does nothing on power-up; keyboard light, power light, and hard drive spin-up show that power supply is working, but screen is gray or black, and disk drive doesn't click.

Possible cause: the processor board is not firmly connected to the mother board, or has worked its way loose (the power LED may flash quickly in this situation). Reseat the connector strip that is parallel to the floppy drive. Since this connector is quite long, it is possible for the ends to be firmly attached while the center is not making adequate contact. Be careful not to flex either board too much while reconnecting them; using a large rubber eraser or other flat object will protect your fingers while pressing the boards together gently. In extreme cases, it may be necessary to use a contact cleaner to clean accumulated gunk (like silicon heatsink compound) from the connectors.

Possible cause: expansion cards not inserted fully or properly. Remove and reinstall.

Possible cause: the motherboard is not supported very well near the internal IDE connector. Solution: gently lift the motherboard near this connector. Installing an insulating support underneath the motherboard near here will be a more permanent solution.

Possible cause: badly-trimmed pins of the soldered power supply connector have poked through the insulating plastic under the motherboard and shorted to the case. Solution: trim the pins and install more insulating plastic.

[motorollin]

Thanks Amiga92570! I will try all of those suggestions.

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moto

[Ronmor]

It the harddrive. The drive will spin no matter what the motherboard is doing (unless there a short in the board).
  The drive will not start reading until it sees the proper operating speed. I test a new harddrives (which is a used drive)for vibrations on a stand a lone power supply. It save the trouble of pulling it back out. :-)

[HammerD]

@motorollin

How did you wire up the microATX power supply and how do you turn on the machine? Do you still use the "long" plastic push button?  I would like to put in a smaller power supply, too, to my A4000 to save valuable space...

[motorollin]

I used the converter cable from Amigakit. Have a look in my gallery if you want to see my PSU conversion :-)

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moto

[A4000_Mad]

@ amigadave

Some great tips there mate 8-)


@ moto

This is perfectly normal behaviour for an A4000 with 3 days of its 1 year warranty remaining.

[HammerD]

@morotollin

Your PSU mod is great! And I like the cut-out you did on the A4000 case at the back..but what tools did you use to cut that? I want to do it :-)

I have already made a Lexan (plexiglass) top cover for my A4000 Looks great! I should upload a pic...but I also want to mod the PSU area and cut out the metal at the back of the case...need to get the tools...

Did you use a Dremel? What else? Thanx

[bigmac]

Hi! I had a similar prob, turned out to be dodgy solder joints on the ATX connector, a quick touchup with the soldering iron and no more probs since, worth checking out.
cheers

[motorollin]

@HammerD
I used a "Silverline" tool which is basically a Dremel (and is compatible with Dremel bits). I used Dremel cutting discs to cut the sections out of the PSU housing.

@bigmac
Do you mean the solder points for the power connector on the A4000 motherboard, or the connectors on the ATX converter cable?

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moto