Help with Amiga 4000 - No Display

anagrama

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Hi All

I've just received an Amiga 4000/40 which doesn't produce any display. When I switch it on it powers up fine and the hard drive starts spinning but the signal turns to a black screen on the television and that's it. I've unplugged the hard drive, removed the memory modules but still the same thing happens.

Does anybody have any advice or possible know what the problem could be?

Thanks
 

Justin

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Hi All

I've just received an Amiga 4000/40 which doesn't produce any display. When I switch it on it powers up fine and the hard drive starts spinning but the signal turns to a black screen on the television and that's it. I've unplugged the hard drive, removed the memory modules but still the same thing happens.

Does anybody have any advice or possible know what the problem could be?

Thanks

are you using just the aga no card? have you checked the lead? what monitor are you using? have you reseated the roms? have you reseated the memory? do the keyboard lights flash? anything else you can tell us?
 

fitzsteve

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How are you connecting it to your TV? When I got my A4000 all I got was a black screen and it turned out the Scart lead and my TV were not compatible.

Try another lead or a Modulator-AV input. Assuming you are using the RGB output.

Steve.
 

abraXXious

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Well, if you have removed ALL the memory modules then it definitely wont work! :)

You need to leave the last module (furthest from the edge of the MB) in as that is the chip ram...., unless it is an A4000-CR (which has the chip ram soldered to the board), but I doubt it is as they did not usually come with an 040.

Take all the simms out, BUT DONT MIX THE CHIP RAM SIMM WITH THE OTHERS!!!! Clean the simm sockets, clean the connect edge of the chip ram simm and reinstall it. Gently press down on the Super Buster chip (which has a tendency to raise out of its socket sometimes) and make sure it is securely fitted. Do the same for the kick start rom chips.

Try it again. If still no good then unplug your floppy drive ribbon cable - if the ribbon cable is plugged in upside down the system will hang at a black screen indefinitely. Now try again. With the floppy unplugged you will have to give it a minute or so to go to the kickstart screen.

See if this helps to begin with.
 

anagrama

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Im currently trying to hook it upto an LCD but have also tried a Commodore 1940 monitor. The scart lead works fine with my 1200 / LCD but ive not tested the 1200 on the monitor yet as ive only just got the monitor also. Maybe its the monitor thats broken? Will test it now and few other things thats been suggested.

Im really hoping this works out, apparently its an ex micropose staff members computer!

Thanks for help guys

---------- Post added at 22:58 ---------- Previous post was at 22:56 ----------

Well, if you have removed ALL the memory modules then it definitely wont work! :)

You need to leave the last module (furthest from the edge of the MB) in as that is the chip ram...., unless it is an A4000-CR (which has the chip ram soldered to the board), but I doubt it is as they did not usually come with an 040.

Take all the simms out, BUT DONT MIX THE CHIP RAM SIMM WITH THE OTHERS!!!! Clean the simm sockets, clean the connect edge of the chip ram simm and reinstall it. Gently press down on the Super Buster chip (which has a tendency to raise out of its socket sometimes) and make sure it is securely fitted. Do the same for the kick start rom chips.

Try it again. If still no good then unplug your floppy drive ribbon cable - if the ribbon cable is plugged in upside down the system will hang at a black screen indefinitely. Now try again. With the floppy unplugged you will have to give it a minute or so to go to the kickstart screen.

See if this helps to begin with.

Ive mixed up the chip ram! I thought they were just memory simms, how do I tell which is the right one? Will I damage the computer if I get them wrong?
 

abraXXious

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Dont panic! (HHGTTG) :)

Okiez, you will NOT do damage by plugging in the wrong simm as the chip ram. BUT, the wrong one will not work, so this may make your job a little more difficult.

USUALLY ram probs are diagnosed by the system as a yellow screen at boot up. The chip ram slot can use various 72 pin simms, but I have found that it seems to be much pickier as to what it likes than the fast ram slots.

See if one of your simms is different to the others. 2mb 72 Pin Simms are quite uncommon, so if you do a search on Google for the code on one of the chips it should tell you the capacity.

Let us know how you go.
 

davideo

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Rubbish reply ;-)

Dave G :cool:
 

HyperD

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Normally it doesn´t matter if you use 2 or a 4MB simm in the chipmem socket.
When you put a disc in the discdrive work the discdrive?
 

Templar

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Did you check the jumpers on the A4000 motherboard?
 

abraXXious

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You would think that hey? But I have found 16 mb simms that work fine as 8mb simms in one a4k mb, but will NOT work as chip ram. I have also have two a4k mbs (both rev b) one will accept 8 mb simms in alternating sockets to give 16mb fast, the other will only show then as 4mb simms (and only show the first one, the second with the empty socket between it does not show up).

As I said, in my experience the chip ram is pickier than the fast on a4ks.


Normally it doesn´t matter if you use 2 or a 4MB simm in the chipmem socket.
When you put a disc in the discdrive work the discdrive?


---------- Post added at 07:38 ---------- Previous post was at 07:36 ----------

Sorry? Yellow screen ISNT ram problems? 2mb 72 pin simms ARE common? a4ks ARE NOT picky about ram?

Please go on... :p

Rubbish reply ;-)

Dave G :cool:
 

HyperD

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I´m pretty sure that i used a few years ago 4mb in the chipmem socket.
But i guess that is not the problem from him when the discdrive load the disc

How are you connecting it to your TV? When I got my A4000 all I got was a black screen and it turned out the Scart lead and my TV were not compatible.

Try another lead or a Modulator-AV input. Assuming you are using the RGB output.

Steve.

That is a good hint!
 

abraXXious

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You would think that hey? But I have found 16 mb simms that work fine as 8mb simms in one a4k mb, but will NOT work as chip ram. I have also have two a4k mbs (both rev b) one will accept 8 mb simms in alternating sockets to give 16mb fast, the other will only show then as 4mb simms (and only show the first one, the second with the empty socket between it does not show up).

As I said, in my experience the chip ram is pickier than the fast on a4ks.


Normally it doesn´t matter if you use 2 or a 4MB simm in the chipmem socket.
When you put a disc in the discdrive work the discdrive?

---------- Post added at 07:38 ---------- Previous post was at 07:36 ----------

Sorry? Yellow screen ISNT ram problems? 2mb 72 pin simms ARE common? a4ks ARE NOT picky about ram?

Please go on... :p

Rubbish reply ;-)

Dave G :cool:

Oh wait, I have it now! A4ks WILL function with no chip ram installed? Erm, Amigas boot FASTER when no DF0 is present?

Am I getting warmer? ;P

---------- Post added at 07:43 ---------- Previous post was at 07:41 ----------

Oh, you can get 4mb simms (and probably 8 and 16) to work as chip ram. That was not the point I was trying to make. I was merely saying that in my (small) experience with A4ks I have found that just because a simm works as fast ram does not mean it will work as chip ram. If this is the case with the simms you have, then you have to figure out which simm was chip ram before it will work. :)



I´m pretty sure that i used a few years ago 4mb in the chipmem socket.
But i guess that is not the problem from him when the discdrive load the disc
 

HyperD

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What i wanna say is when the discdrive works its not the chipram problem with a wrong simm.
 

abraXXious

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Ah, sorry, did not see that. :) Well, you must have had the chip ram simm installed if you were getting df0 to activate at boot up.

Did you have the chip ram installed? Or is it an A4000 CR?
 

anagrama

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Can I ask if the chip ram anything special or can i use another modual - Also am I right to say the slot furthest from the edge of the motherboard is for the chip ram, this is what it says next to it.

Sorry for my lack of knowledge on this one, this is the first 4000 ive had!

Someone suggested I re-sit the roms, how do I get them off the motherboard?
 

davideo

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There should be 5 slots for the RAM. The one nearest the daughter board slot is for Chip RAM (y)

Dave G :cool:
 

abraXXious

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Yessum, you should have 5 x 72 pin simm slots (then your A4000 is definitely NOT an A4000-CR). As Davideo stated, the one closest to the daughterboard (furthest from the edge of the motherboard) is the chip ram slot.

Let us know if your fast ram simms work as chip ram (when you get the machine up and running), just out of interest. :)
 

anagrama

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Im confused, is there a difference between the chip ram and fast ram? How do I tell the difference?
 

davideo

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The Fast Ram should be 4 sticks of 4mb and the Chip Ram should be 1 stick of 2mb.

Can you see one stick different to the other four?

Dave G :cool:
 

anagrama

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There was three sticks in the amiga when I got it and all three are different. Ill search them on google, Im looking for a 2mb stick arent I ?
 
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