Plan C | Amiga 500 Plus Blue Screen and or 'No Signal' Repair (Older Vid - Rough Audio) @Plan-C | Uploaded February 2016 | Updated October 2024, 1 hour ago.
Another Amiga fix! This one wasn't too bad. It had the usual battery corrosion plus a damaged pin on the Agnus socket but it drove me nuts. Removed Battery and cleaned up traces. Replaced and socketed U12 chip (74LS244N). Tidied up connections but could not find the cause of the blue screen / 'no video' signal for ages. Turns out there is a through-board connection next to the battery which connects Garry pin 4 to U12 pin1 which was rotten but not easy to spot by eye.
Also, there was no connection on pin 30 of Agnus due to a damaged socket.
Whilst trying to work it out I checked for a clock, swapped custom chips, cleaned-up the ram expansion port and socketed all the RAM.
Good luck all.
Another Amiga fix! This one wasn't too bad. It had the usual battery corrosion plus a damaged pin on the Agnus socket but it drove me nuts. Removed Battery and cleaned up traces. Replaced and socketed U12 chip (74LS244N). Tidied up connections but could not find the cause of the blue screen / 'no video' signal for ages. Turns out there is a through-board connection next to the battery which connects Garry pin 4 to U12 pin1 which was rotten but not easy to spot by eye.
Also, there was no connection on pin 30 of Agnus due to a damaged socket.
Whilst trying to work it out I checked for a clock, swapped custom chips, cleaned-up the ram expansion port and socketed all the RAM.
Good luck all.
