I think my A4000 may be dead.

[ShadesOfGrey]

I'd like to apologize before hand if this message tends to ramble a bit.  It's late(~04:20 EDT), I'm tried, and most importantly I'm really pissed off.


Here's what happened.  Earlier this week I recieved the stand offs/spacers I talked about in an earlier thread.  So I set about putting my A4000 back together.  Of course I went and made the biggest mistake one can possibly make when putting together any computer...  I put everything in, without testing each component as I installed them....

What's worse, I had an omen that things were going to go wrong...

I put the oscillator crystal in backward after it had fallen out of its socket on my accelerator.

I dislike GVP products intensely.  I've heard they used to make great gear back in the day, but every single piece of GVP hardware I've ever had had problems.  From the GVP 030 Combo I got along with my first Amiga to the T-Rex II I got in my A4000.  It's just ashame there seems to be so much of it in circulation.  In particular, the T-Rex II I have and the Tekmagic I had, have oscillator crystal sockets that are very 'loose'.  On the Tekmagice, I had to tape the crystal into its socket or it would fall out.  The same is almost true of the T-Rex.  

Naturally, I had to disassemble my Amiga again in order to get at anything.  So anyway, after re-seating the T-Rex twice, I noticed the crystal was in backward and fixed it.  When I next turned on my A4000, I got a red screen (that flashed on twice) and my power led flashed several times.  I remember the red screen indicating bad (or loose) ROMs.  And I tried pushing the ROMs back down and got another blank screen.  I turned the Amiga off and then on again.  The result was I got the red screen(s) again and then a yellow and the same pulses on the power LED.  I looked up the yellow screen (680x0 error) on the net and tried re-seating the T-Rex again.  Red screen and LED pulses again.  So this time I pulled out the accelerator and pulled out the ROM chips and put them back in.  This time I got a got a flashing green screen and I think the LED pulsing.  I looked up the green screen and checked my chip RAM.  Turned the Amiga off and then on again, blank screen, off/on, blank screen, off/on red, yellow, flashing green, pulsing LED.  So I pulled everything out and put it back in.  Now all I get when I turn on my Amiga is a blank screen.

In the end, I suspect I'll have to make the long journey to Software Hut and have them take a look at it.  But if anybody has any suggestions I'd like to give them a shot.


FYI, I seem to recall that the power LED would quickly pulse 5 or 6 times and then one longer pulse.  Oh and BTW, my A4000 is a Rev. B (with, AFAIK, the latest rev. chips) and I'm using 3.1 (40.68) Kick Start ROMs.

[zipper]

I've read that a turned Xtal usually burns just in seconds....

[filson]

yep, crystals are very sensitive. some will even die under transport. a dead crystal will give 680x0 errors dependent uppon the design of the accelerator. otherwise it will just lock up the machine at boot.

[Brian]

How about unplugging everything and test just the motherboard, then put in one board/card at a time till you find what it is that is acting up? But for the crystal being in the wrong way around I just can just agree with above... get a new one cause that one is a goner.  :-(

[ShadesOfGrey]

@Brian

Uhh, will an A4000 (desktop BTW) display any error codes without a processor installed?  I've never tried it, so I don't know if it's possible.  If a processor is needed and the problem is the crystal, then I won't be able to test the moptherboard.

-Edit- I did try removing the processor card and chip ram...  Since I didn't get any error message, I'm assuming the processor must be present for any error codes to be displayed.  This is leading me to believe the problem (hopefully) has to do with my accelerator card.  If that's the case, I'm going to try and ditch this piece of **** T-Rex II.

[ShadesOfGrey]

While rummaging around, I found a 30MHz crystal I bought to try and overclock the T-Rex II.  IIRC, I was able to at least get as far as the Early Startup screen.  Now I don't even get that far...

...  Although, I just tried pulling the chip ram while the processor card is installed.  I am getting the pulsing LED again and a green screen.  Which, under the circumstances, would seem to me be progress.  The LED will pulse anywhere from two times all the way up to eleven times (10 short + 1 long pulse, which, from what I've read isn't normal).  I don't get the green screen or the pulsing LED if  the chip RAM is replaced.

So, does anyone know what the significance of the pulsing LED is?  Does the number and duration of pulses specify the error present?  Why do I get an error screen when the chip RAM is removed, but absolutely nothing when it is?

[filson]

once read that they can identify errors like the guru or the colors of the startup screen. check the amiga.org faq for more info.

[ShadesOfGrey]

@filson

I know what the colors signify (looked them up last night...  err...  This morning).  

From the Amiga.Org FAQ section:

[color=990000]· Amiga 1200 / 4000 Startup Colors?[/color]

The A1200 and 4000 perform several hardware checks as they start up. If the screen remains on any of the following colors on bootup, here is what they mean:

-Black
Opening screen
Initial Hardware tests passed
Initial system software tests passed
Final initialisation test passed

-Red
ROM error, reseat or replace Kickstart ROMS (this can also be caused by worn insulation covering the back end of the pins that connect an IDE cable to a hard drive, aka short).

-Green
Chip RAM error

-Blue
Custom Chip(s) error

-Yellow
68000 detected error before software trapped it (software or hardware error

I hope this helps the A1200 and A4000(T) users in our community.

But the pulsing LED, IIRC, has some significance as well.  I just can't find anything that tells me exactly what 10 short pulses + 1 longer one means.  

[odin]

@shades:

Just a thought here, tried a different simm for the chipram? (At least I presume the 4000 uses a simm for chipram). Perhaps the simm is fried?

[filson]

maybe this can help too:
http://home.arcor.de/r69/amiga/A4k-HW3.html#power-upself-test
http://www.allexperts.com/previousqv.asp?QuestionID=2778721

they might not apply, contain duplicate information or just be boring, but thats for you to deside.
additionally you can try to get your hands on a copy of the Amiga hardware reference manual. It should contain all the boot codes. (or was it the Rom Kernal reference manual ?! :-) )

[filson]

ShadesOfGrey wrote:
@filson

I know what the colors signify (looked them up last night...  err...  This morning).  


But the pulsing LED, IIRC, has some significance as well.  I just can't find anything that tells me exactly what 10 short pulses + 1 longer one means.  

yes i remember. had something similar with an Apollo 060 card. just can't seem to find a link on the net for it. sorry.

[Brian]

Sorry.. thought you had the original CPU board around to use instead while testing stuff (or better yet a soldered on 030 like my old 4K had .

[ShadesOfGrey]

@odin

I would, but I'm not sure what type of SIMM I should use.  That is to say, can I stick an 8 or 16 MB SIMM in that slot or dies it have to be 2MB (or 4MB as the SIMM I have seems to be (16x256K))?

[ShadesOfGrey]

@filson

I know!  I keep finding info on the caps lock LED codes, but nothing on the power LED.

I've sent an email to Software Hut's (where I got the A4000) repair tech Chris in hopes he can shed some light on the problem.

[ShadesOfGrey]

@filson

Thanks for the URLs, but they pretty much have the same info as I got elsewhere.  I had a hardware reference manual for my A2000, but alas, I have none for my A4000.