1200 black screen on powerup help!

[Descent]

Hi,

I have an Amiga 1200 motherboard rev 1B ROM 3.0 39.106 as soon as power is turned on I am greeted with a black screen. The drive still clicks and workbench disk will boot in but always a black screen.  Tried all video outputs RGB Comp RF and 3 TV/monitors and tried different PSUs including an A500 PSU. Also re-seated ROMs. There is no accelerators or memory expansions attached, it is just a stand alone 1200.

So I am guessing it is an internal video fault.

If there is anyway to resolve this please help.

Thanks.

[Angus]

You've tried all the things I can think of. No hard drive either, from what you say? If it were a video fault I would have expected the it to be just one of the outputs,but I suppose it is a possibility. At this point I would (using anti static precautions) try gently pressing gently on pretty much any chip I could see, and then retrying the power. But I'm no electronics engineer. Hopefully somebody else has some better advice? This is a potential PowerVixxen LT we are talking about!

[Homer]

Hmm, did you turn the tv/monitors on ?  
  :lol:
I can't remember how many chips were socketed on the A1200 mobo, but I don't think there's many, you may be better trying an A520 modulator from an A500 if you have one hanging around and see what happens with that. After that its repair shop time by the sound of it :-(
Did it suddenly stop working ? Did you do something that may have caused the failure ?? Good luck

[x56h34]

Try turning on the Amiga and hold both mouse buttons pressed. If you see the early-boot-screen on your display (TV or RGB) then most likely there is a display driver that gets loaded from the HD, which your TV and monitor do not support.

Also try powering on without the hard drive connected to the 2.5" port, if the above suggestion fails.

[Descent]

It was just a board that I bid for. Unfortunately only the ROMs have sockets. I had thought of trying an A520 but I wasn’t getting any RGB output. But I will try anyway.

I also tried the two mouse buttons at boot still nothing. Not even a screen flicker on reset. But the computer still works just can’t see anything. I do have another 1200 which works fine. So I think the boards video output is dead!!! Never mind.

Anyway, Thanks for the help.

Descent.

[orange]

You could also check if chips are getting too hot/cold.

[Descent]

I shall try to have a fiddle around with the board a bit more but I think it is a bit of a loss.

Thanks for the advice