View Full Version : Apple II plus - request help diagnosing problem

August 14th, 2006, 04:22 PM
Hi - I am not as experienced with Apple hardware as other systems. Can someone tell me what it means when you turn on your Apple II plus and the screen looks like this:


Some details...
1. THere is a 16K RAM expansion card installed in slot 0. There is a jumper cable that goes from the card into the back left RAM socket on the mother board. When removed the system has a garbled screen upon restart.
2. There is a VIDEX card and associated small socket add-on card. When removed there is no difference
3. There is a APL card for a printer and a disk drive interface card.

ROM issue?



Terry Yager
August 14th, 2006, 06:27 PM
I dunno everything, but if you remove the 16K RAM expansion card (for troubleshooting, etc), you must remove one of the chips from the expansion card and place it into the socket on the mainboard that the card was formerly jacked into.


August 14th, 2006, 09:19 PM
You might want to reset the chips. Do any of them have badly oxidized legs on them? They will look dark and discolored. If they are I wil tell you how to clean them. Even clean the edges of the controler card, and the memory card.

Tarn-X followed by Alcohol.

Memory or Rom is most likely. Some Bad disk might hang the controler

Take Care

Micom 2000
August 16th, 2006, 05:24 PM
Don't know, but my gut reaction would be keyboard problem. Too many repeats to be a memory or card problem IMHO. If it does stop after repeating that sequence, it could be a cold solder joint that gives up after heating.


August 16th, 2006, 09:07 PM
thanks. I will look into your suggestions. I think that I agree with Terry...pop out the socket and put in a known working chip. I will let you know... I should have some spares.

August 25th, 2006, 05:22 AM
The Videx board might be the issue. If you remove it, I believe the IC in the socket board is a 9337 but I'm going off old memory. To get the apple II working it is always best to remove all cards, even ram cards first. Use caution when removing the videx card not to bend and break pins on the smaller board. On some versions you can remove the IC in the socket 74259 and replace it on the motherboard in the IIplus. If you can't remove the IC from the smaller videx board, you need to buy this IC.

When I troubleshoot Apple II's I start by removing and reseating all IC's the make sure they are making good contact and that the tin pins on the chips are clean. Power supplies are always suspect too and fail often.