Nightmare! My A4000 won't start any more! :((

[spavatch]

I've just got back home as summer holidays come to an end and guess what - she won't run any more :cry:.
Here's what it looks like. I press the power switch, both power and hdd leds are lit, all the fans and hdd spin up... and from this point it acts quite unpredictable. Most times it won't boot up from FDD even after disconnecting the HDD, sometimes it boots up like it should but after a while, just before workbench screen would appear, it freezes so hard even Ctrl+A+A combo won't help.
I've been advised to dismantle everything, blow away all the dust and then reassemble it. No effect, none :-(.
Any ideas what could possibly happen? Please, tell me it's not serious... :bigcry:

[seer]

Don't know, a number of things.

Battery leakage.
HD died.
Loose chips.

Best thing to do is to disconnect as much as possible( like all hard drives, zorro expansions etc etc), look if any chips have gotten loose (or if any memory is unseated or CPU daughterboard) and try again.

Anybody else ?

[bonkers]

Beign an 4000 I would say that the CPU-board has has jumped out of position. Happens to my computer all the time, just press on the top of the CPU-board and I would think that it should boot up just fine.

[spavatch]

seer wrote:
Don't know, a number of things.

Battery leakage.
HD died.
Loose chips.

Best thing to do is to disconnect as much as possible( like all hard drives, zorro expansions etc etc), look if any chips have gotten loose (or if any memory is unseated or CPU daughterboard) and try again.

Anybody else ?

I've done all that, everything is fitted and looks sound, no loose parts. HDD looks okay however I can't say I'm 100% sure. But even if it was HDD's fault it would boot up from a diskette after disconnecting the faulty HDD, right? And the floppy drive remains silent...
Oh, and battery's almost new, it's been replaced with a brand new one a year ago or so.

[x56h34]

What CPU board are you using?
Try fitting a different one and see what happens.
Remove EVERYTHING from the system but 2MB of chip ram and (preferably) the stock CPU board, and see if you can boot. For the 030 C= CPU board, set the clock jumpers to INT and if you have an A3640, then EXT.

[Doobrey]

Check the PSU and the PSU connector.

If the +5v line is too low, it can cause the reset line to go low and hold the CPU inactive until the +5 gets within tolerance again.

[spavatch]

Oh, Mr. Toecutter :-D. I'm using A3640 CPU board and I'm afraid it won't be so easy to try your ideas in practice. Simply, there aren't any A4000 around. Maybe in some Amiga service-shop...
I'll try to connect a TV :-?, maybe there are some guru messages that can't be seen using a VGA screen in CGX mode? And speaking of the PSU, I'll try to examine that too.

[Tomas]

i would check the psu if i was you.

[puppy]

so do i have the same problem with my a4000T i sent it to Amiga France to be checked and it seemed to be a battery clock problem
Came repaired but two months later it happened the same.

[x56h34]

I can send you my working 030 cpu board, if you wanna try and test your system. I suspect that your CPU board is busted, most likely.

[magnetic]

It would be very advisable to hook up this Amiga to an RGB monitor or vid monitor with adaptor. You may be getting an error message in native amiga mode you cant see on your vga monitor...

realize

[spavatch]

Okay guys, here's what I found out. I've hooked up a proper (meaning: old) TV and tried to fire her up. She didn't boot up from HDD, instead a welcoming screen (disk & drive) has appeared and after a while everything went dark - a freeze. After a while (half an hour or so) i did the same, this time - pressing both mouse buttons at once. The boot-up menu has appeared but then again, everything disappeared before I even clicked any option...
Any ideas now...?

[bloodline]

spavatch wrote:
Okay guys, here's what I found out. I've hooked up a proper (meaning: old) TV and tried to fire her up. She didn't boot up from HDD, instead a welcoming screen (disk & drive) has appeared and after a while everything went dark - a freeze. After a while (half an hour or so) i did the same, this time - pressing both mouse buttons at once. The boot-up menu has appeared but then again, everything disappeared before I even clicked any option...
Any ideas now...?

Maybe something is overheating.

[TjLaZer]

You definately have a HARDWARE problem.  Was the machine stripped bare when you did this test?  If not strip to the bare minimum.  Chip RAM, no fast, no HD, no Floppy, no Zorro backplance.  Reseat the CPU card.  See if that helps.

[spavatch]

I think that overheating is not the issue here, running-stable-period is too short, just a few seconds.
Actually... I'm afraid of removing RAM modules, those sockets are pretty fragile... :-(