You have probably been asked this a 1000 times, but I'm a noob so forgive me. The A2000 Rev6 was given to me, no idea how old it is. The power supply was no good so I used an old ATX and modified it to use on the Amiga, voltages are all good. the old battery was slightly corroded, removed it and cleaned up the MB with vinegar \, there was no damage to the MB all traces are good. All I get when powered on is a black screen. I have a working A500 so I removed all the custom chips from the A2000 one at a time and they all worked fine the A500. I move the Tick jumper, had no effect. I am using RGB out to a upconverter so I can use my flat screen tv. So I,m at a bit of a loss of what to try next. I also removed the floppy drives and the HD card. The power light comes on steady. So any suggestions for me to try would be a great help.