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:

[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.

[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.

[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...?

[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... :-(

[spavatch]

TjLaZer wrote:
Well if you want to effectively troubleshoot your Amiga 4000 problems, you are going to have to remove the Fast RAM SIMMs.  It could very well be a bad seated or damaged SIMM module.

Okay, I'll try to do it. Any ideas how to remove RAM modules without proper meshing things up? You know how fragile those sockets are... :-(

[spavatch]

Actually, the PSU has been refurbished some time ago. The case remains stock but "all-that-inside-stuff" was changed, now it's 200W instead of 145. But I'll try to examine that.
S#!+, how I regret not buying that scandoubler-flickerfixer thingy... :-(