a600 blak screen

[cpiac64]

i have a600 from ebay, black screen, power led and capslock on.

repair or return to ebayer?

[s2325]

Do you hear floppy drive seeking disk?

[cpiac64]

half second tourn if floppy are insert, not click from haed, without floppy silence

[ferix]

just bad caps, replace them (or return It to the seller).

[FOL]

Originally Posted by cpiac64

i have a600 from ebay, black screen, power led and capslock on.

repair or return to ebayer?

Does it have a kickstart installed?

[cpiac64]

i have open the a600, test tension on connector floppy, 12 volt is ok, 5 volt are 4,80

i look with oscylloscope for any signal on cpu, i go read the schematics

[rkauer]

@FOL: if the drive clicks, even just one time at power on, the machine is not dead.

Bad caps is my first suspect.

[Zetr0]

Originally Posted by cpiac64

i have a600 from ebay, black screen, power led and capslock on.

repair or return to ebayer?

if you got it very cheap it could be a simple fix, if however you paid a fair price for the item I would return it and get your money back.

you could always arange with the seller a part-refund as an option.

[cpiac64]

the ebayer offer only part of money, exclude postage if i return it and new postage with my money, but i have reply no.

i have open a600, the reset is zero and i suppose ic or capacitor broken on 5 volt

[cpiac64]

i search a signal go down one second post ali on

[cpiac64]

ok, i have desolder ne555 and C612, net the mainboard, resolded ne555 and new C612, now reset is ok, but the floppy is dead, i have open the floppy and is sure dead, i change the floppy (i mount fujitsu M2537B0IB), now add harddrive and is ok, but the mouse don't go, next time test a game with joy.

p.s.
with 2,05 capslock blink, with 3.1 not

[Zetr0]

@cpiac64

Glad you are getting somewhere with this little monster - stick with it my friend I am sure you can get back to the land of fully living.

now. the 2.05 rom capslock blink is normal as my A600 Ks3.1 doens't but my 2.03 does (as does my A2000)


Now recently I have been caught out with a very silly mistake in attempting to repair the mouse probelm of an A1200 - originally looking at the schematic I assumed POTX and POTY to be part of the mouse and hence tied directly to paula... no this is not the case - had I of managed to of taken my head out of my butt for five minutes I would of realized that its Mouse_DAT and Mouse_CLK that I need to be tracking as such this is governed by a small -easily replaceable IC..

which (as is the A1200) U34 - 74LS166

On the A600 U34 is found between the Chip RAM and mouse port.

[cpiac64]

i need a ls157 as u34, i serch in my rubber

[cpiac64]

i found new only hc and hct SO16, ls only dip16

[cpiac64]

i found 2 ram on my old vga-pci for piggyback and i have soldered, now a600 are 2 mega chipram

[Zetr0]

@cpiac64

I am deeply sorry my friend, you are correct - its an 74HC157

you can get them here for £0.99p + postage

good luck =)

[cpiac64]

i desoldered 74f157 from my a1200 turbocard and soldered on a600 but mouse dont go, suspect paula, denise of agnus in fault.

with joy is ok i have play at lotusII

[rkauer]

Mouse movement is managed by Denise/Lisa.

[Zetr0]

@rkauer

According the schematics U34 - 74LS157 handles the mouse off to Denise - the LS157 is the first link in the chain.


@cpiac64

Buzzing out the following on a multimeter might help

Joy/Mouse Port links

U34: 74LS157
[pin 4]  signal( M0V )
[pin 7]  signal( M0H )
[pin 9]  signal( M0V )
[pin 12] signal( M1H )


U4: Denise

[pin 41] signal( M0V )
[pin 10] signal( M0H )
[pin 42] signal( M0V )
[pin 9]  signal( M1H )


U7: (8520)
[pin 11] signal( _Fire1 )
[pin 10] signal( _Fire0 )


U3: Paula (8364)
[pin 36] signal( POT0Y )
[pin 35] signal( POT0X )
[pin 32] signal( POT1Y ) (check as schematic is blurred)
[pin 38] signal( POT1X ) (check as schematic is blurred)

hope that lot helps.

[cpiac64]

Originally Posted by Zetr0

@rkauer

According the schematics U34 - 74LS157 handles the mouse off to Denise - the LS157 is the first link in the chain.


@cpiac64

Buzzing out the following on a multimeter might help

Joy/Mouse Port links

U34: 74LS157
[pin 4]  signal( M0V )
[pin 7]  signal( M0H )
[pin 9]  signal( M0V )
[pin 12] signal( M1H )


U4: Denise

[pin 41] signal( M0V )
[pin 10] signal( M0H )
[pin 42] signal( M0V )
[pin 9]  signal( M1H )


U7: (8520)
[pin 11] signal( _Fire1 )
[pin 10] signal( _Fire0 )


U3: Paula (8364)
[pin 36] signal( POT0Y )
[pin 35] signal( POT0X )
[pin 32] signal( POT1Y ) (check as schematic is blurred)
[pin 38] signal( POT1X ) (check as schematic is blurred)

hope that lot helps.

thanks, the number of the pin in the schematics-pdf of a600 are not clear

i buzzered half of signal but nothing, i test with oscillope now