Amiga 1200 flashing lights

[sturulez]

Today I turned on my amiga. I noticed a red screen and the power light flashing. Then after about 5 seconds the screen goes green then red again. It then continues to repeat this process. I disconnected the RAM expansion in the trap door and the PCIMA card but that had no effect.

My amiga is only about 3 years old as bought it from amigakit.com

Any idea how to resolve this problem?


Thanks

[sturulez]

Opened up the amiga. Pressed down on the ROMS. Turned it on and the red light appears. Seems like the green one has gone

[sturulez]

Okay, I've swapped the ROMS around with another amiga 1200 I have for spare parts. I seated both ROMS in turned on the amiga and the green light came on but nothing else.
HDD doesn't even boot. Screen is just blank. So I then thought about replacing the ROMS and sticking the original ones back in. Once I done that still nothing just the power light on.

Can someone tell me if there is a correct way of installing the ROMS. Do they sit over to the left or over to the right?


Thanks

[sturulez]

Yes i did notice at one point when I inserted the ROMS and turned the machine on they did get hot. Guess that means they are fried?
 
Would you recommend upgrading to 3.1?

[sturulez]

Okay. I purchased some new ROMS. Installed them by following the instructions. Powered the amiga up. It then successfully gets to workbench. Then suddenly the yellow screen appears. Turn the main power off and turn it back on again the power light appears with the yellow screen and flickers for a few seconds before the screen goes blank.

Is anyone able to shine any light on this matter?

Thanks.

By the way I have unplugged the PCIMA card, 4mb expansion card, HDD, floppy drive and still the yellow light comes on

[sturulez]

Okay I've replaced the power supply. Has made no difference. Though I'd connect the Floppy disk drive, but I get no ticking noise when I turn the machine back on. If it is the capacitors which ones do I need to check?

Thanks

[sturulez]

Okay, I've removed the heat shield. Visually inspected the circuit board, can't find anything unusual as described in the post above

So the next step I take it would be to check the voltages? If so could someone tell me where I would start.

Many thanks

[sturulez]

Or could the motherboard be completely fried?

[sturulez]

Okay, Ive swapped the mainboard with another A1200 i had tucked away. Powered it up and it works fine.
The motherboad that stopped working was a Rev 1A. not sure if that has any effect to it, i know there are a few board Revisions out there and each have their own problems.
Cant see any dull solder joints or leakages.
 
As to what led up to this fault, im not really to sure. I purchased the amiga from amiga kit about 3 years ago and it was working fine till recently. It would freeze during a game and then the screen would go red. I found that if turned the power off for about 5 mins then turned it back on again it was fine.