Commodore Amiga Retro

So you bought an A600

Lets go round again ?

DAY TWO

There was nothing for it sadly, the A600 wasn`t working
today, and no amount of tweaking would bring her to life
So with screwdriver in hand I set about taking her apart one
more time. This time however I decided to strip the A600 down
to the motherboard. In doing so I would need to remove the keyboard

Simple job but one that may puzzle you when re-assembling. Simply
pull the blue ( or green ) ribbon from the white clasp and remove
the clasp. Remember which way it went. Simply put the clip back
on the ribbon. To refix, simply push the ribbon into the slot and
slide the white clamp over the receiver on the keyboard.

For some reason the end of the ribbon has gone brown on this
machine. Maybe wrong but can`t remember seeing that before.

With the keyboard removed, unfix the floppy drive and remove all
the wires, connectors and ribbon. What you should have then is a
view of the complete motherboard

Remember, had this been an A1200 you would at this
juncture normally un-hinge the small metal clasps to the shielding
raising them to the vertical, and remove the hd cradle to expose
the motherboard. The A600 has the metal clasps but no shielding

There is one screw to the front holding the motherboard to the
casing. Having un-screwed this carfully remove the motherboard with
base shielding from the case. Then unscrew the rear port connectors
and remove the motherboard from the shielding

Its worth making a note of the motherboard revision number for
future reference. Note the words `June Bug`... a summer release
for the A600.

I was suspiscious of damage in two areas. First I checked over
the power connector and carefully adjusted the modulator so they
were not touching.

Next I checked all the connectors to the floppy end. All seemed fine
and there were no obvious marks under the board or to any of the
chips or connectors. I then gave the board a good hoover, stuck
it in the washing machine and gave it a good iron... scrub those
last two items. She was then clean as a whistle. Be very careful
not to damage any of the tracks on the motherboard, it only takes
one and the whole unit will be lost

I decided I couldn`t leave the casing to the floppy damaged
so I dragged out that floppy drive that I replaced on the A1200
and swapped the casings.

That made me feel much better, and shows why you should never
throw stuff away. Anyway the floppy was back together and looking
like a good one.

I wasn`t happy with the ROM chip seating so I carefully removed
the ROM and checked the legs. Not for the faint hearted this one
What you need to do is gently raise the ROM from each end in turn
You do this very slowly and very gently. Once removed you must check
the legs to see if all OK. Also remember which way the chip came
out. Sometimes worth putting a bit of tipex on one end. This is
more important on the A1200 as there are two and you need to
remember which order they came out. On the end of the chip there
is a half circle indent which lines up with the receiving part
on the motherbaord.

Confusing this, as there are more holes than legs. Look for the
small arrow on the motherboard and this will direct you to put the
ROM chip in starting from the far end ie leave the holes clear
nearest the arrow.

If you study the top of the ROM chip you can see the version
reference. In this case, 1991 V2.05 37.300. You can upgrade
your A600 by replacing this ROM chip. Fortunately 37.300 will
support hard-drives, but only of 40 Mb and less.

Not the Loch Ness Monster ( duo ) but the only clips still
intact on the back of the A600. You need to look after these
little clips, they are what holds the machine together

And here is one I made earlier. All you need to do now is
plug the keyboard back onto the unit and hold your breath..

She didn`t work... ar hum

Thinks

Last resort, more power. So out comes Goliath which is a PSU
unit similar to the power unit on a PC, complete with fan
And guess what ?............

That did the trick... well I`ll be.

Just shows you. You have to go round the houses sometimes to
find the answer, but find it I did. The power unit wasn`t feeding
enough juice. I actually think it was a faulty connector
Thing is I did try another power unit, but it was the one from
that other A1200, and I never checked if it was working, cus I
used another power unit to drive the A1200

Anyway the A600 is working fine now, and fires up first time
every time. I am so happy.

Time for just one more game of Batman me thinks