To A1200 owners... I need help PLS!!!

[starf81]

Hi! I've just got my "new" A1200 and now I'm testing it.

I've noticed a strange behaviour when I turn on it... despite my other Amigas, the A1200 needs a lot of seconds (I think at least 15 or 20) to start. It's the same when I reboot pushing CTRL + A + A keys: it needs a long time to display the purple "welcome" screen. Do your 1200s take so long time, too?

After, I've tested the A1200 with an Apollo 1240 and the purple screen comes immediately. However, when I use the Apollo, the Amiga crashes after very few minutes... could be the power supply? I'm using an A500+ power supply.

Last question: looking to the motherboard (REV 1D4), I can see a resistor in the lower part, at the right of "Alice" chip. It doesn't seem to be soldered by Commodore (it's not so perfect...) but the picture into amiga-hardware.com site has the same resistor. What is its function?

MANY THANKS!!!!
Alex

[starf81]

First of all thanks for your replies!

Ok for the boot time...

Regarding the Apollo:

1) At the moment my machine is fully opened and the Apollo has a good fan...

2) I'll try to adapt an ATX power supply. However, when I tested, I haven't any other peripherals linked to the Amiga.

3) I was reading about this problem on several sites... :-(
Any tips about it? Is the modify sure?

4) No, I don't think... it crashes during the purple screen, too.

Another question  :-D ... I'm reading about compatibility problems with my revision (1D4), including something with 31khz screen mode. Is it true? How I can fix?

THANKS AGAIN!
Alex

[starf81]

Ok... I've completed my tests.

I've cleaned all contacts with a spray (type G-22) on Amiga and Apollo side. It still crashes.

Rigidity seems ok as its attachment to the motherboard.

Neverthless, the Apollo has a socketed ROM and its pins are not so good  :-(
I've noticed that a pin is broken and the previous owner soldered it with the nearest pin at its left. I hope they have the same function. Do you know if and where I can found a new ROM? Otherwise, anyone has an Apollo schematic to check it?

In addition, the original battery has been changed with one bigger that doesn't permit me to close the 1200's trapdoor. So the 1200 doesn't touch the table as it should.

During my tests I've noticed that the Amiga crashes when I move it... so, it should be a syntom of poor contact, but I can't find it!

If it is necessary, I'll remove the two parts as stated in Ian Stedman's site but if the problem is another I prefer to not modify the motherboard.

I'm very confused  :-?  :-?  :-?
Alex

[starf81]

Perfect, thanks!

I've forgotten a detail: sometimes, after its spontanous reboot, the screen is yellow.

Alex

[starf81]

Ok, I think to have solved my issue. I've discovered a contact problem with a socket and now seems to work well (none crash for two hours...).

However I've modified the motherboard (rev. 1D4), too. I've removed the E123C and E125C components as stated in a lot of sites. All work correctly.

But... now I've another problem to solve!  :-D
I'll ask about it in a new thread...

THANKS AGAIN FOR YOUR HELP, MY FRIENDS!!!  :-)
Alex