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I've read through Apple II Plus/IIE Troubleshooting and Repair guide and I've have swapped every chip from ones off a working //e and I still get a checkerboard when I turn it on.
Voltage is good on the power supply, no cards and I am using the keyboard from the //e that boots and works fine.
any steps to bring this board back to life would be much appreciated.
thanks!
-Neil
Hello Neil,
You don't mention if all the chips are socketed on the defective Apple //e motherboard.
Only the oldest ones have all the chips easily replaceable.
Maybe a RAM issue. Maybe the motherboard has the RAM soldered in.
Hi!
It's a fully socketed //e. Does a checkerboard indicate a RAM check?
thanks for all the help!
-Neil
Neil,
No, the RAM check doesn't produce this pattern on the screen.
It could be bad RAM, ROM, CPU or logic ICs, or even a combination !
If you have a working Apple //e, you can try to swap some chips to see if there is any change and finally find the culprit(s).
Neil
I'm thinking you are in 40 char text mode but no bit clock to generate the characters. When you press ctrl-reset, do you hear a corresponding beep?
If so, try typing HGR return. Does the screen clear? If screen changes, attach a photo.
Larry G
Could be a broken trace or a bad socket. Does it look like any modifications have been made? Have you removed the motherboard and looked at the underside? Is there any leaky capacitors or signs of corrosion or water damage?
I assume when you say you've swapped every chip, you mean every single chip and not just a lot of them.