Amiga 1200 Black screen. CPU DEAD?

Hi!

I tested my Blizzard 1230 accelerator on my recently bought A1200. When I turned the power on the power led is lit up but the disk drive dosent start to "tick" and the screen is all black. I removed the accelerator and turned the power back on. But the screen is still black. Have I ruined my new Amiga? My thought's are that I fried the CPU or the IO chip. And if I did is it possible to buy an 680020 processor today or the IO chip? I don't know where to start.
Please help me!

Its not the CPU imho.
CIA chip or the I/O chip possibly?

The 68020 is soldered on to the mobo and pretty ahrd to replace if at all - the 68030 accelerator should override the internal processor anyway.

Because this uses surface mount technology, it might be difficult to repair - can anyone confirm whether any of the chips are removeable?

Have you tried making sure the ROMS chips are in position by pushing them down? Take antistatic precautions.

Rude!

The thing is that it was running fine just before i plugged the accelerator in. Could the ROM chips been taking damage?

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I had the exact same thing happen to me - it turned out to be the brick PSU - the additional load of the accelerator must have been to much for its hardened power arteries.

bty - I learned the hard way always to use an A500 PSU whenever I accelerated anything Amiga.

You can hack an Amiga power plug onto a cheap PC PSU too.

They vary a lot, when i build my A4k into a tower and
plugged a lot of power extensions to it, i had random
crashes which became worse, after the system getting warm

I first thought of a cold solder spot (dunno if this is the
right word for it), but after more testing (and switching
back to onboard 030 due to broken PPC card) it went away.

It wasn't the mainboard or the ppc board, in the end i
changed the PSU to a PeeCee model, with Amiga plug and since
then it is as stable as it can be (even beats the AOne, but
i don't do beta stuff on it)

Hope you can sort it out,

edit: Nevermind the last paragraph, that is for the A4K
check the mainboard ram, you need
at least the chip ram on the mainboard properly seated,
maybe it got loose while working with the ppc...

Just looking at possibilities....

Are you able to use a different display method at all, for instance if you are displaying via the RGB, can you use the RF out instead, or vica versa?

Did you have floppy drive activity before?

Is there a hard drive that might have had its cable knocked?

Have any of your friends got a spare 1200/600/500 power supply in their attic? :)

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I find this quite shocking.

I know they [Commodore] used to change the internal floppy disk drives more often than Mcdonalds happy meal toys but to think they changed the specifications of the A500 PSU brick I find very disturbing.

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In these parts we call 'em dry joints.
The solder will have a slighlty crystalline appearance and will need to be reworked with a touch more flux.

@Mothman
I too had this happen it was the power supply tho lucky
it died with the extra load so i then used the A500 power supply untill i got new 1200 one but it still would not run properly had to use 500 power supply :) so go for that first

@sister_Rita
I actaully have several of the A500 power supplies now but no longer use any of them as the 1200 is now a ppc1200 fully towered
and i use A1 most of the time

Hi again!

Thank you all for your answer's and tips.

Then again I actually used an A500 powersupply and it was running fine. Until I plugged the accelerator card in. Before everything worked perfectly. I removed the accelerator card and reinstalled the memory expansion card that was fitted there originally (when everything worked fine). But now there's no disc activity and the screen is black. When I try to reboot CRTL+A+A the Caps lock lit's up for a second but the power light dosen't dim down as it usually do when u reboot.
And the black screen dosen't even flicker.

I havent tried the Composit connection yet though.
But the rgb connection worked fine as well before.

I turned on the computer for like 10 seconds with the accelerator card installed, the screen stayed black then I removed it and the screen stays black and there's no disc activity.

I tested my powersupply with my A600 and it worked fine.

Hi again =)

I removed the originally fitted memory expansion card so that the Amiga became "original". And connected the composite cable. And then suddenly after 2 restarts it suddenly worked again. But there was no picture from the rgb connection.
Then I reconnected the memory expansion card and tada! everything worked fine?... I do wonder if something happend when I fitted the Accelerator card cause u need to push quite hard to get it in place. Anyway it works fine now and I know there's something wrong with the Accelerator card. There's no response from the Amiga when it's fitted. To bad... but I'm thrilled that it works again. Thank you all!!


(By the way the caps-lock only flashed once)


BR Jerry.L

Hmm, i'm not that familiar with A1200 mobos, with the A4k
one has to change a jumper on the mobo, isn't that the case
with an A1200?

@Mothman

Accelerators slide on a lot easier without the standard A1200 casing. I remember having to remove parts of inside of the cover in order to refit it with the first 030 which I think was probably a Viper 1230 MK2.

My Blizzard 1260 suffers slightly from the ZX80 ram pack wobbles in my A1200 Tower. If it isn't titled towards the rear side of the motherboard I get a black screen like you describe.

Perhaps the trapdoor cover is pushing the card upwards slightly or did you leave it off anyway. If there seems to be any play in the card try make sure it is angled down slithtly.

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Great!

It's fantastic that another Amiga has been wrestled from the claws of death and is amongst us again.

This is joyous news, indeed.

What a wonderful response from all our fellow Amigan.net anigans - three cheers!

@Mothman

congrats its working
its always good too see it still works bet you yelled out in joy

Ok...

Will try this. It would be great if I got it to work. =)
There is quite a difference with it on even though its only 10Mhz difference, but there's also the extra ram memory.
Is it possible to run it whitout the ram memory?

Actually I did make a sort of sqeaky woman like sound when it started to work again ;) ....

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An AT psu is easy and cheap (can be even free) to get and there're plenty of diagrams how to wire the A1200 power cable to it. However the fact that removal of the accelerator didn't help is a bad sign...

Jack