A4000 black screen, suggestions to fix?

[rlake]

I've just been given an A4000 but it's a little temperamental. To begin with there was a green screen, cured by pushing the socketed chips. It seemed fine, workbench booted etc. Okay, so the it needs the keyboard replacing, a new front for the case, ...

So, I decided to try an IDE hard disk and ariadne ethernet card but ever since I get a black screen (a visible rectangle on my LCD; using a scan doubler in the video port). The boot process clearly hasn't started because the floppy drive is silent.

I've tried removing/replacing all boards to the bare minimum that was working, even to the extent of swapping to a spare CPU board (both rev 3.0 040). All I've noticed during this is that the scan doubler board's connector is fairly worn.

I'm running out of ideas, is there anything further I may be able to do to save it?

[Severin]

Right, first of all pull all chips in sockets one at a time and clean them by rubbing them on a sheet of A4 paper...

Check around the battery for any leakage, check the simms are in place, the A4000 simm sockets are crap, you might have to cable-tie the simms down...

Remove the daughter board, clean the contacts, push it back and pull it out a few times to clean the slot on the MoBo.

Same for the CPU card, remove/replace a few times to clean the contacts.

If that doesn't do anything, chech all the voltages of the PSU...

[Slayer]

I don't know what it is with people in general by
why do you insist on running before you can walk *grin*
Your letter is also lacking in exact procedure... I
mean for when you installed the IDE did you boot off that
or still off your floppy... I wish I could assume
the obvious but in this situation never assume anything

If I was you... I'd go right back to when you had the
system booting via floppy disk... and ONLY install the
IDE harddrive and boot the system with no startup-sequence
see if you get a shell... then procedure step by step
via that... i.e. issuing each command in the startup-
sequence.. depending on how customised the sequence
is it could be simply software related... an incompatiable
setpatch blah blah...

If all else fails let me know if you wish to get rid
of the A4000... I collect them *GRIN*

this is an A4000 system I am typing into at this moment


have fun

adios!

[cv643d]

How do you rub a chip in A4 paper? Is it the pins side that are rubbed?

[rlake]

Slayer: I booted off neither . Since it's currently PC formatted I assumed I'd either get the insert floppy screen or the boot menu if I hold both mouse buttons. The first objective is to get something to appear on the screen, my procedure is currently (i) turn power on and wait, here's my precise setup:

I have an open case sat in front of me with mouse, keyboard and via a "petsoff" dblscan video card, a feed to my monitor. The PSU is a converted AT supply powering the motherboard and floppy (ribbon cable connected also). All other cables are removed (IDE). I have the CPU board in place, and so far arranged the SIMMs from fully occupied through to just chip RAM.

Severin: The battery has been removed, but cleaning the contacts and custom chips sounds like a good idea... so, given my tools are a bit lacking, what do I need to remove them? I foresee a trip the Maplin's heh...

[Jope]

Ok, first, pull all expansions out (leave the chips on the motherboard ;-)

Check the backplane's solder side carefully. See if any pins there have bent and are now touching each other (you added a HD and a Zorro card - both actions might have bent them). Unbend them before replacing the backplane.

Then plug in only:
- the backplane
- the Chip RAM SIMM (if your machine doesn't have the Chip RAM soldered on the motherboard)
- the cpu card (not applicable if you have an 030 on the mobo and the jumpers set accordingly)
- the floppy drive
- the scandoubler

Be careful to fit the cpu card in properly, use a rubber eraser to push down on it - otherwise the fast slot connector's pins will hurt your thumbs. :-)

Did you get any life out of the machine now?

Try and pull the socketed chips out a bit and pushing them back down. The only socketed chips should be the kickstart roms and sometimes the buster. Be careful with the buster as the PLCC socket cracks very easily.

Anything yet?

If you still get nothing, you should measure the psu to see if you get correct voltages. The pinout should be at www.hardwarebook.net

[Severin]

Originally posted by rlake
Severin: The battery has been removed, but cleaning the contacts and custom chips sounds like a good idea... so, given my tools are a bit lacking, what do I need to remove them? I foresee a trip the Maplin's heh...

all you need a 2 tiny flat head screwdrivers (the type for glasses etc) then just gently push them under the roms and slowly lever them up one side at a time. for the buster, you could try 'Eyetech's bent paperclip' method... I have a PDF file with complete construction details if you want it

[Severin]

Originally posted by cv643d
How do you rub a chip in A4 paper? Is it the pins side that are rubbed?

Yes, most sockets contact the outside edge of the pins, rubbing them on a bit of A4 paper cleans off any oxydisation, you would be surprised how much you can get off before the pins are bright and shiny again...

[rlake]

Originally posted by Severin
for the buster, you could try 'Eyetech's bent paperclip' method... I have a PDF file with complete construction details if you want it

A paperclip and plier contraption , and a previously white piece of paper later... no luck (sigh).

I think I'll have to try my chances at picking up a Super Buster / 8374 Alice or trying a modulator to bypass the video card, I have one but not at hand.

Curses.

[Slayer]

okokok

time out... hold it!!!!

Now, with the bare unit and after pushing in the chips
to remedy the green screen the Amiga booted to workbench
this is correct? Off floppy because you haven't got the
IDE in there yet...

Okay, you hook up the IDE and only the IDE... now? It
won't boot off floppy disk? Because if the IDE is of
course formatted for another machine, namely PC then
the Amiga wouldn't give one toss about it and merrily
boot up from the workbench/install disk... If it is
not getting past the boot process then it's something
else...

Do you ensure the IDE is actually a compatiable model,
is it set for Master mode and no slave... etc etc...

Good Luck, but my current view of the whole scenario is
you're missing something small as in hardware oversight
since if the Amiga truely boots off the floppy blah
blah and you've run diagnostic carefully from that
inital modest setup then I'd be pointing my finger at
the IDE and/or cabling, perhaps... perhaps you might
consider sticking to the 4 gb limit outside of 3.5 and
other filesystem criteria...

OOooo I'd love to get my hands on that A4000 *grin* I
just love those tough love cases...

adios!

[rlake]

Originally posted by Slayer
okokok

OOooo I'd love to get my hands on that A4000 *grin* I
just love those tough love cases...

adios!

... that's the thing, it doesn't really have much of a case left! It's survived shipping from Norway at least but it's missing the front.

By the way, I'm not connecting any IDE or using the floppy right now... it really is worse than that! It's a black screen *before* getting anywhere through a boot process.

[Slayer]

ahhhhhhh... SO when you said:

I've just been given an A4000 but it's a little temperamental.
To begin with there was a green screen, cured by pushing the
socketed chips. It seemed fine, workbench booted etc.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

you just mean you had an insert disk animation prompt?

boggle

Well good luck then, I'm a lil lost now

And I say Norty Ppl for not looking after such a
wonderful piece of technofunkiehardware prior
to your possession ,)

adios!

[Severin]

Hmmm, I think your best bet would be the totally non-existant until now 'N.A.I.C.' or Newent Amiga Intensive-care Centre, located in Newent, Glos.

If anyone want's Amiga hardware checked out, and they can get it here (and back) I'll test it for free (and maybe even get it working until my spares run out)

[Heavyweight7t6]

Man I got this same problem!!! arghhhhhh