Jump to content
Sign in to follow this  

Project: Apple IIc video/boot problem

Recommended Posts

SO I have a new project IIc.


When I power it up I get no disk drive spin, just power and vertical color bars.


After disassembling it I found an anomaly at the location of the character ROM socket.


The socket is a 28-pin.


The chip in it is 24-pin, labeled 342-0265-A, and if i move it around slightly it get variations in the video output.


I believe this chip may be a video ROM chip for a IIe enhancement kit? (No real knowledge here, just a google search).


Is this the correct chip for the IIc?


Any help would be great.



Share this post

Link to post
Share on other sites

If you're getting no disk drive spin, no beep, the problem isn't in the character generation circuit.


Your CPU most likely isn't starting up, so suspect a failed keyboard (holding Ctrl-Reset, or having the keyboard unplugged, can cause those symptoms IIRC), failed CPU, failed ROM, or failed first bank of RAM (IIRC in that order). Could also be the IOU or MMU, but that's getting lower in likelihood IIRC.

Edited by bhtooefr

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this