Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: J_Biscuit on December 10, 2007, 09:42:14 PM
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Right.. my first foray back to the land of Amiga it appears is not a simple journey.. I bought a 1200, and simply put it don't look good!
I had to wait to get hold of a power supply, and now that i have.. Disaster!
It's like this, on powering up no led's light up, caps light doesn't show, no sounds from floppy, just a med/light grey screen via composite out to tv via scart.
No smoke, no fire.. no other colours on screen.. Just wondering if you peeps have any ideas? Don't get me wrong the 1200 is a lovely retro paperweight, it just could've been more!
any help appreciated, i doubt it's a fixer but i'll have a go. :-)
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Check the PSU! Is it a converted peecee unit? Is it set to 220V? Your home's outlets are 110V ?
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No smoke or fire? I should sincerely hope not! :roflmao:
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yup.. converted pc unit, +12 and -12 wrong way round? (ARRGH! it isn't)
Supplies too weak? (lower voltage than required?)
But i'm more concerned about the board being a lemon..
oh i'm in the uk so 240 ish here..
The thing for me is the fact it displays a comodore grey screen, no corruption but nothing else.. cpu deaded? fried roms? some other custom chip crisped? I'm not au fait with 12's, so whether its a complete fubar or partial i don't know..
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Open the Amiga (it's easy, only 6 screws), flip the cover and keyboard, and test the voltages on the power conector (from inside) with a multimeter.
An easy spot to do this is the floppy power conector (+5 and +12V).
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There's some interesting reading about screen colours here:
http://www.amigahistory.co.uk/selftest.html
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It's like this, on powering up no led's light up, caps light doesn't show, no sounds from floppy, just a med/light grey screen via composite out to tv via scart.
It should go black to gray to white. Does the screen change color at all?
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BTW: gray screen appears on a busted or half-asset PSU.
At least it appears in mine now-fixed A2000...
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"it displays a comodore grey screen."
sounds to me like you're in workbench! it ain't faulty. :lol:
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no change of colour of screen, immediately shows complete and standard grey..
currently modding a old IBM ps for the job to check.. as much as you might bemoan IBM, build quality is above par.. supply gives correct v's to within about 2%.. other one not so trusty..
Thanks for the help i'll keep you posted on it..
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Heheh.. very good..
(inwardly goes "fuxake!!")
monami wrote:
"it displays a comodore grey screen."
sounds to me like you're in workbench! it ain't faulty. :lol:
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The A1200 should go from dark grey to grey to finally (after around 25 secs) the insert disk animation.
The cold boot sequence stuck on a dark grey shows a defective A1200 motherboard.
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Thanks amigakit.. that's the thing, i'm aware that there is a specific sequence of colours displayed on the screen to represent self test results.. but with mine.. no dark grey.. straight to normal workbench grey.. at least as i remember it. :-)
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holy mary mother of biscuits..
LIFE!! we got a purple screen, with disk anim, and every thing..
Thanks to the boy from Brazil who spoke about {bleep}e power supplies causing the grey screen, between you and IBM's manufacturing policies i've got a 12 that i can play with!
The journey begins here..
Thanks Amiga.org :-D
Oh the fault was a very poor 12v supply.. courtesy of a dell spec brick. How the hell the PC it ran worked god only knows, new found respect for the hardware, hardware.. not the generic operating system.. ;-)
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You're wellcome!
BTW: my real name is Rogério, the equivalent to "Roger" in english.
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Seriously Rogério without that little snippet of info you gave me i would've had the thing apart, tracing and testing for ages thinking it was a hardware problem on the board, and probably doing more damage on the way..
The old "is it plugged in" analogy.
Top work fella :cheers: