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[leofoe]

I have two problems with my A4000/030 KS3.1 OS3.9, which I think are related.
Problem 1 is the PSU connector to the motherboard. If I push it down all the way, the machine will definitely not boot. I have to fiddle and then it might boot. Tried a different PSU: same problem.
Once this problem is solved, I have a second problem: The A4000 most of the time gurus on cold boot. After pushing the LMB it works fine. No problems with a reset.

[orange]

probably bad solder joint; when you push it, it detaches..
try resoldering

[leofoe]

I looked at the back of the motherboard: the solder joints (which are quite big), look good.
Sometimes I get a yellow screen for a second in stead of the guru I mentioned. After that it boots fine.

[patrik]

It really sounds like a problem with the solders as you have a problem with a bad connection in some side of the connection - and as you have tried another PSU with the same result, the problem should be with the motherboard connector part.

If some of the solders are broken, there will be small small cracks going round the pin, which can be hard to see if you don't look really really close.

Also make sure the round tube-shaped pins inside the motherboard part of the connector arent burnt or mishaped, they should look like those on these motherboards.


/Patrik

[beller]

Sounds like two distinct problems to me. The first has generated all the responses, the solder on the PSU connectors to the motherboard appear to have problems.

The other problem, non-booting may not be so bad. I'm assuming you're booting to a HDrive. It takes a few moments, when first powered on, for the drive to get up to speed. Your Amiga attempts to boot before its fully ready and you get a guru. Normally the machine will then reboot fine, which you say yours does. Sounds typical. My 4000 does it occassionally. Only solution would be to try different and faster drives. I haven't bothered.

Bob

[leofoe]

@patrik: If it were the solder joints, why does it boot OK all the time once I fiddled it working?
Are these joints only at the back of the motherboard?

@beller: This problem never occured before I got the non-booting problem. That's why I think they are related. Besides, why would it guru? Instead I would expect the insert disk screen to appear.

[beller]

True...I usually get the boot screen but sometimes guru and a yellow screen. Do you have a CD drive? Any chance there's a CD in it that's causing a problem at boot?

Bob

[patrik]

@leofoe:

If you fiddle with it until the broken solder-joints makes contact, ofcourse it gets power then. What makes me suspect they are broken the most, is that you say that it never works if you push it down all the way, as that would be the best way of separating the contact areas of broken solder joints of this type.

These joints are at the back of the motherboard. Have someone experienced with soldering have a look at them.


/Patrik

[CLS2086]

Hi,
you should also clean your SIMMs ! Sometime there is oxydation and durst on the connectors ... ;-)