A1200 boot problems!

[melange]

Hey, am I seeing that correctly?  Shouldn't the yellow (assuming that's shield, Amarelo=yellow?) wire be connected to the ground for shield.  Isn't it kinda dangerous to have +5v around the shield?  :-?

[gertsy]

The problem is not pluggin the mouse or joystick in, but shorting accross the port pins with the metal surround of the mouse plug. If any of the pins are shorted against pin 7 (+5v) you risk damaging your miggy.
Actually this is very difficult to do because the metal surround is recessed quite some way from the front edge of the mouse plug.
I have plugged in Joysticks and Mouses directly into my powered on Amigas for 20 years.  I have never had an amiga die. Just luck or care ?

BTW: If you put your pinky on the metal pin of a live AC plug when you insert it into a AC socket you could seriously damage your heart muscles and/or kill yourself.  Rare but it can happen.  You need to afford your miggy the same care.

When plugging into the serial, diskdrive and monitor ports you really should power off your miggy as these ports have 12v on them.  But as the manual says to be safe always power off before plugging and unplugging items.

On the original problem,  I liked the sound of the power supply being the issue but the fact that the problem still occurs with the accel removed points to the Roms or a deeper problem. Having 2 miggys makes it easier to knock our pwr supply issues.  Have a look here and see if any of this fits:
http://www.amigahistory.co.uk/selftest.html

BTW. I have always used my std black A1200 power supply on my 030 33 cobra / 6Gb drive A1200. No probs. knock on wood.

:rtfm:

[melange]

Yep, I agree, we have strayed off the subject a little.  I am very concerned about that PSU Mod above though.  The A500 manual shows the Sheild connected to ground.  God knows what would happen if you did that.  Assuming the mod above worked, I'm kinda suprised.
@rkauer
Have you done this mod?

[Lokki]

That shield ground doesn't look right at all in that PSU...
It's 'Shield Ground' not 'Shield +5v'....
The last few power supplies I've had that were converted, and a couple I just made myself haven't got it connected at all, doesn't cause problems on A500s at least.

On the subject of hot swapping port 1, it's definitely not just a bad luck thing. I've fried port 1 on a friend's Amiga (which I bought right after) by 'twiddling' the joystick as he plugged it in. It fried the logic chip there. I've also had a number of Amigas with dead CIAs hitting port 1, some I've caused myself and others I've recently bought that way.

[melange]

It's got like a POWER SHIELD!!!  :lol:
Extra, extra protection from..........  something?   :oops:

But seriously, I hope nobody uses that to mod with an 1200/500 PSU lead, it's wrong, and if it was to touch ground...  :shocked:  :-o  :-(

As lokki has pointed out.  The shield does not have to be connected at all, but it most definitely should not be connected to +5V

[scuzzb494]

In answer to your question I would first suggest you have a dicky floppy drive. ( but most likely not ) If you disconnect the floppy drive the machine takes the kinda time you are suggesting to boot. Try an external floppy drive unit, and simply comply with the Commodore Amiga 1200 instruction manual which states that other than a PCMCIA card you cannot plug anything in or switch anything on and off while the machine is hot. That is a golden rule and is why my 1993 Amiga 1200 is still alive. I don`t think its power. Floppy drives can be found on Ebay and my site shows how to fit one.. Could be that something has become a touch loose, like the ribbon to the floppy or the power cable..

One other issue may be shorting out. I had this problem with a couple of cards where the accelerator was causing probs with the shielding. Also press the ROM chips down firmly and check that all the shielding is firmly seated...

AND NOW THE RULE BREAKING BIT...

You can fold the keyboard back on itself resting such that it doesn`t pull the ribbon or wires out and power up with the casing open ( at your risk ) and see if that remedies the problem. If so it is shielding. Sometimes you have to run a strip of insulating tape between the casing and the accelerator where it connects to the motherboard. I have machines with tape and paper in to stop bits touching. Some clever so and so put a reset pin on one mobo that actually touched the shielding with the case closed. Given that you opened the case and put the new ROMs in and installed the Blizzard I would go for poor connection.

By the way... And this is quite dangerous, but can be seen on my website under cardboard Amiga, you can fully remove the motherboard, lay it on a clean flat none metal surface plug in your monitor mouse and keyboard then power and see if she boots... Thats a good way to see if the computer works. Then simply ( with power off ) add each part to see which is causing the problem. ( try doing that with a PC ) I would start with the accelerator. An external floppy drive will be useful. It will take a while to boot without the internal floppy drive. Get SysInfo off Aminet and run that when its working. There really are so few bits to go wrong with the A1200. Also get a brick from an A500. I never have used the original A1200 power supply.. useless... really useless. Also replace the SIMM on the Blizzard.

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