A1200 Dead??

[Havana7]

Hi! After some years I want to return to Amiga computer, but I think that my A1200 is dead.

This is the problem:

  When I switch on my power supply (AT or ATX) my amiga do nothing, the screen get black and nothing more, sometimes it looks like the floppy tries to read. I touched the chips to see if they get hot and they do, are hot, the proccesor and AGA chipset are hot.

  So, I´m totally lost and I want to know if my amiga is really dead before buying another motherboard.

Thank you.

P.D.: Excuse my poor english but I´m spanish and my english is poor and forgotten.

[orange]

If floppy moves only once on powerup, its a bad sign because IIRC it would do that even when connected only to PSU, without computer.
Can you test other video outputs and voltages? Have you disconnected all cards/HDD..? Don't forget that it takes some time to boot without a HDD.

[Havana7]

Yes, I´ve tested other video signals.

About voltages... When I test the computer,I disconnect everything (except floppy), but I´ve tried with a Blizzard 1230 and a BlizzardPPC (with and without a Bvision), in the BPPC the fans runs correctly, but the results are the same.

Ammm, HDD should not be the problem, i left the computer in power on some minutes.

[CLS2086]

It could be the fault of the floppy motor.
Take off the keyboard, floppy connectorS and power it without any card, wait about 1 min. you can also try to put your 1230-IV and you'll have some thin blue light at the power on if all is ok.

[Havana7]

OK. I´ve tried it CLS2086 but nothing happends, no blue line.

I think my amiga is really dead...

[CLS2086]

Did you try to take off and reseat your MX Eeprom and to power it by the floppy psu connector in the right "way" (wrong way kills the 1200...) and wait around 2 min while pressing both mouse buttons.

[CLS2086]

If you can, take a multimeter and check the psu in load and off load , and also with and without floppy drive.
Does your LED are corrected in the right way ?
Is your keyboard and others extension well unpluged ?

[Havana7]

I think I would try to reset my MX Eprom if I know how to do it, could you explain it to me please?

Thank you very very very much.

[lopos]

Havana7 wrote:
I think I would try to reset my MX Eprom if I know how to do it, could you explain it to me please?

Thank you very very very much.

I think what he meant by 'MX EPROM' is your Kickstart EPROM's.
Check if your kickstarts are seated correctly.

[Havana7]

Yes, I know it, I change Kickstart chips few years ago to install OS 3.5 and they were working perfectly.

But, if they can be reseted I would try it.

Thanks.

[CLS2086]

Sorry for the misunderstood, i meant to take them off, brush them, clean them with a contact cleaner spray and the support too.
But by which imput do you power it ?

[Havana7]

My power input is soldered directly to the mainboard, it has been working too many years, but i will try to use the floppy connector.

[orange]

IIRC, its not advisable to use both inputs at same time