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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: bitman on March 24, 2013, 12:40:24 AM

Title: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 12:40:24 AM
Today I picked up a Commodore Amiga 4000T (pictures) (http://www.amibay.com/showpost.php?p=438828&postcount=3523) - it was bought as untested/not working, since we couldn't get it up and running at the seller.

After some troubleshooting (replacing processor, mem and disabling all cards), I found out that it only  works if I kill the IDE disc (have tried 2 HDs).

The machine is stripped down - so only Floppy and SCSI CD rom is connected to the drive module. And the IDE disc is connected to the IDE pins on the mobo.

But it wont boot with the IDE attached - any known issues (have consulted the manual)
Title: Re: Commodore A4000T troubleshooting
Post by: esc on March 24, 2013, 12:50:13 AM
It won't boot, as in black screen?  Different color screen?  Does it give you the "insert disk" screen?

Also, I saw you got an A3000 mobo in the lot.  I have an empty a3000 case.  Maybe we can work something out...send me a pm.  :)
Title: Re: Commodore A4000T troubleshooting
Post by: Akiko on March 24, 2013, 01:06:49 AM
is that an original Commodore A4000T?
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 01:07:17 AM
Yes, just black screen.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 01:07:57 AM
Quote from: Akiko;730123
is that an original Commodore A4000T?

Yes, very original.
Title: Re: Commodore A4000T troubleshooting
Post by: Akiko on March 24, 2013, 01:09:18 AM
Wow.. Congrats :)
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 01:11:52 AM
@Akiko

Thanks - this is what the beauty looks like:
Title: Re: Commodore A4000T troubleshooting
Post by: midway on March 24, 2013, 02:27:21 AM
Nice!

Ide cable intact? Hd on cable select, master or slave? Set on the terminal connector? Sometimes the ide cable is misplaced connecting not all pins...
Although you would have seen that.

Try another ide harddisk, maybe its dead. Does it spin up? Feel with your finger if you cant hear it.
Try a cdrom (ide) if you dont have another hd.
Can you take some pictures from the inside?
Title: Re: Commodore A4000T troubleshooting
Post by: smerf on March 24, 2013, 05:26:50 AM
Quote from: bitman;730120
Today I picked up a Commodore Amiga 4000T (pictures) (http://www.amibay.com/showpost.php?p=438828&postcount=3523) - it was bought as untested/not working, since we couldn't get it up and running at the seller.

After some troubleshooting (replacing processor, mem and disabling all cards), I found out that it only  works if I kill the IDE disc (have tried 2 HDs).

The machine is stripped down - so only Floppy and SCSI CD rom is connected to the drive module. And the IDE disc is connected to the IDE pins on the mobo.

But it wont boot with the IDE attached - any known issues (have consulted the manual)


Hi,

Hate to tell you this but it sounds like a weak power supply breaking down under load, but if you have another hard drive try that first, doesn't have to be super huge, just something to hook up that you know runs well in another computer. If it still blanks out then you know your power supply can be breaking down under load.

smerf
Title: Re: Commodore A4000T troubleshooting
Post by: smerf on March 24, 2013, 05:29:28 AM
Hi again,

If you can try hooking up a cdrom instead of hard drive, if it still blanks out, then disconnect the cdrom, and see if it runs again. In other words try to load down the power supply and see what happens. If you have other things in there that you can disconnect like 64 megs of memory, try reducing it down to say 8 megs, or if you have a graphics card, try disconnecting. In other words keep the hard drive in but disconnect other things to lighten the load, this will show if you are overloading the Power supply or if it is breaking down under load.

smerf
Title: Re: Commodore A4000T troubleshooting
Post by: dannyp1 on March 24, 2013, 05:36:18 AM
Could you post a picture of the label with the serial number from the back of the tower?  Thanks!
Title: Re: Commodore A4000T troubleshooting
Post by: Markus_Bieler on March 24, 2013, 07:28:05 AM
- If you have a spare powerunit, then connect  the HDD to that one and try again.
 - The hdd is spinning up?
 - press both mousebuttons on startup (early boot/startup screen), tell what you see there
 - Sometimes a bad RDB can issue this failure

But I guess it is a bad powerunit. They are old now and at that time C= hadn't as much money as to the times of the A3000, so they used cheaper parts.

Could also be leaking electronic components on the motherboard.

Markus (A4000T, but AT-version)
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 09:15:07 AM
HD jumper is set to Master - have a few other HD's and CD-cards that I can test out. Will also test it with an extra power supply, but the drive spins up without problems.

Will also test the IDE cable.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 09:29:15 AM
Here's a few more pics from the inside. Note that the sticker on the back says EU and the silverlabel has a note about "funkenstort".

To my knowledge, the seller worked at CBM Denmark.

The two mobo pictures is available as highres at BBOAH (http://www.bigbookofamigahardware.com/bboah/product.aspx?id=31)
Title: Re: Commodore A4000T troubleshooting
Post by: Amiga_CDTV on March 24, 2013, 11:42:53 AM
Congrats! It's a gorgeus machine. And wow, from CBM Denmark. Does the machine have an original HDD installed? Any insider-CBM software in there?

Is there something wrong with the front door or is it just taped for transport?

If you want to replace the PSU, get a ATX to AT PSU adapter (like this (http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=39&products_id=306)). I use one in my (AT) A4000T.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 11:49:30 AM
The door, has a minor missing part - but it's easily fixed.

What's on the disk is still unknown (it won't boot with the disk attached).

Besides the A4T I also got an A4000D and a A2000 from the same guy (http://hol.abime.net/hol_search.php?N_ref_artist=3539), so it's exiting to see what these disk have of goodies. Got some printed material "confidential developer notes" for CD32 and a few CBM internal demo CD's for CDTV.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 12:31:32 PM
Now this is strange:

Attached a third IDE HD, and the machine stated loading WB - unfortunately the HD has a WB that is set up to a high resolution, so I had to connect the Amiga to a Multiscan monitor (MicroVitec) - but as soon as I attach it to the Microvitec - the disk wont start. If I switch back to Philips CM8833-II the disk starts again?

Strange!
Title: Re: Commodore A4000T troubleshooting
Post by: mongo on March 24, 2013, 01:27:18 PM
Quote from: bitman;730172
Now this is strange:

Attached a third IDE HD, and the machine stated loading WB - unfortunately the HD has a WB that is set up to a high resolution, so I had to connect the Amiga to a Multiscan monitor (MicroVitec) - but as soon as I attach it to the Microvitec - the disk wont start. If I switch back to Philips CM8833-II the disk starts again?

Strange!


Use the Philips CM8833-II and boot with no startup sequence.
Title: Re: Commodore A4000T troubleshooting
Post by: Matt_H on March 24, 2013, 02:25:13 PM
Are you using any sort of VGA adapter? I had a problem with a 2000 that just simply would not boot (couldn't even get to early startup) if I had a VGA monitor connected. Something to do with genlock circuitry, I think. It was a straight-through pin-conversion adapter, not one of the silverboxes which has some added logic.

The other thing I can think of is that the Amiga is getting confused by a hidden RDB flag. I had a 4000D that would also refuse to boot after I connected a new hard drive. I eventually found some combination of drives that allowed me to boot. I was able to get into HDToolbox and received the "drives have been added or removed from the system" message. Acknowledging that message and saving changes sets the RDB flag that there are no more drives and that the system should stop looking and start booting.

If you connect the 4000T's drive to another Amiga, you might be able to set that flag manually (with a different hard drive utility - just make sure to back up the RDB first!) and get the machine to boot.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 24, 2013, 09:45:52 PM
@Matt_H

Yes, I used a standard straight-through VGA adapter that works fine with my A1200's, have now switched to a CBM Silver adapter, which makes the A4000 work with the MicroVitec (should probably just have used the 1942 that came with the A4000....)

I can now boot from one of my IDE disks - will set the other disk up as slave and see if I can fix it.

I read somewhere that workbench.library needs to be on disk, since it's missing in the ROM - that could explain why WB shows up, but never gets 100% working.

But conclusion is - A4000T works, with the right combination of monitors and HD's

Thanks for the help everyone.
Title: Re: Commodore A4000T troubleshooting
Post by: Ami_GFX on March 24, 2013, 11:06:22 PM
Quote from: bitman;730210

I read somewhere that workbench.library needs to be on disk, since it's missing in the ROM - that could explain why WB shows up, but never gets 100% working.



That's exactly it. I recently acquired an A4000T and the workbench.library needs to be in the Libs directory and if it isn't, the system hangs at workbench load. The original disk that came with the A4000T should have it on. My A4000T came with a SCSI system disk and I first transferred the original system to an IDE compact flash card/adapter combo and then did a fresh install of WB3.1 on another CF card. It hung just at the point where Workbench loaded with an empty workbench. I had to make a custom boot floppy with the workbench.library file and copy it to the Libs directory and it worked fine. I've had problems trying to get 2 IDE drives to work together on my A4000D. A hard drive and an IDE cd/dvd drive are no problem but I could never get the same CF adapter to work with the IDE drive at the same time in my A4000D. I got it to work by itself and transferred the system with Winuae to a 4gb CF card but it gave me data errors, even with the max tranfer rate correctly set. I gave up on it and went back to a 2.5" IDE drive.  It worked without any problems at all when I put it in the A4000T.
Title: Re: Commodore A4000T troubleshooting
Post by: Matt_H on March 25, 2013, 02:14:02 AM
Yes, without workbench.library the "Workbench Screen" will appear, but the actual Workbench window won't. If you can't retrieve workbench.library from the disks that came with the 4000T, you can extract it from another 3.1 ROM using the RomSplit/Remus tools and then copy it by hand from the boot-without-startup-sequence shell.
Title: Re: Commodore A4000T troubleshooting
Post by: midway on March 25, 2013, 03:19:37 AM
Actually if you use idefix (software) you should be able to use DVD Roms, IDE 2 CF adapters and so on without problems ! I had the same issue once, the CF adapter was not recognised at all, even when alone on the bus.
 
Hey, that with the 4000T Rom is funny, I always wondered why only the workbench taskbar would show up when loading any other 3.1 WB disk than the 4000T in a 4000T, even 1.3 and so on...I had once an a4000D with the 40.70 roms in it, someone must have been confused when putting that 4000D together:roflmao:
 
Great to know !
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 26, 2013, 02:53:04 PM
With the help of romsplit (http://www.doobreynet.co.uk/beta/index.html) and an A1200 with the latest ROM's i managed to extract a workbench.library file that works with the 4000T - but is still looking for the original install disks.
Title: Re: Commodore A4000T troubleshooting
Post by: Ami_GFX on March 26, 2013, 03:38:57 PM
The procedure I used to install Workbench 3.1 was to make a custom boot disk with the O60 libs and workbench.library from a copy if the standard WB3.1 install disk. I had to remove quite a few of the install files to make room for it. You won't need the 060 libs but you will still need to delete some files. Once I booted the A4000T from that floppy, I removed it and inserted the full WB3.1 Install disk, did the complete installation, and reinserted the custom boot disk at the end and manually copied the workbench.library and 060 library files to the Libs directory.

There must have been a special set of install disks for the A4000T but I have no idea where to look for them.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 26, 2013, 04:19:48 PM
Will try your install procdure, when re-installing.
Title: Re: Commodore A4000T troubleshooting
Post by: darksun9210 on March 28, 2013, 05:42:03 PM
even if it is working, may be worth having a check of the 5V power lines to the mainboard (Orangy red cables) from the PSU
i had a fully loaded ESCOM vintage A4kT and managed to melt the tangs inside the plugs that connected to the mainboard from the PSU.
an easy swap, but went through two PC/AT PSU's that way. the mainboard wasn't damaged, just the plugs got scorch marks!
Title: Re: Commodore A4000T troubleshooting
Post by: zipper on March 28, 2013, 07:00:02 PM
It's typical in A4000 - you're not the first one!
Title: Re: Commodore A4000T troubleshooting
Post by: Erol on March 29, 2013, 05:53:38 PM
Hi,

Drop me an email i can send you the A4000T manual,  its the Amiga Technolgoies manual but the Commodore board is almost identical minus differences in the case and release versions of the SCSI/AUDIO/IDE module boards.

I would be careful in using A1200 Workbench library as the A4000T has extra workbench disk which contains several additional files including a different workbench.library (i think its 40.70) which is not the same 'revision' as the A1200 ROM release.
If you have OS3.9 you can pull the files from that CD as it has everything you need.
It contains the install for OS3.1 as well on that CD.

The IDE port will only support 2x PIO-0 , personally I would only use the internal IDE for CDROM and use the SCSI bus for any Storage Media its much faster  (talking from experience) but again thats my personal choice.

Be careful with VGA adaptors, ecspecially external flicker fixers as they run hot on these machines...  
Get a GFX Card ASAP..   small vga adaptors should be fine

Also if you doing any kind of changes with the case off make sure that the power is unplugged and your earthed, you be surprised how quickly you can blow the board with static.   ive done it once... so im letting you know be extra careful.
Title: Re: Commodore A4000T troubleshooting
Post by: bitman on March 30, 2013, 12:10:57 AM
@Erol

Thanks for the tips. I'll just check and see if I have the A4000 manual - it also seems like I now have the correct disks for 4000T.

I'll avoid the VGA adapters and put in my spare Cybervision 64