Project: IIc video/boot problem

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Offline
Joined: Dec 20 2003
Posts: 130

SO I have a new project IIc.

When I power it up I get no disk drive spin, just power LED 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.

Thx

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Offline
Joined: May 27 2013
Posts: 792
Re: Project: IIc video/boot problem

According to this picture of an Apple iic motherboard, the chip is the correct one and it is meant to be installed in the manner you see in the picture.

If the picture appears to be too small when viewing it and if your mouse cursor becomes a magnifying glass when it goes over the picture then you can enlarge it enough to see the character generator rom socket.

http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20II/Apple%20IIc/Photos/Apple%20IIc%20ROM%2004%20-%20Motherboard%20Front.jpg

Perhaps if you clean the pins on the chip and remove and reinsert the chip a few times, your computer will boot.

Just make sure you do this when the computer is off.

Offline
Joined: Dec 20 2003
Posts: 130
Re: Project: IIc video/boot problem

Well, back to the drawing board. I swapped in a known good Character ROM and even a known good 65C02 (Both from a Platinum IIe)...

Netted same results... Sad

Prob, just let it slide away... got too many projects now.