Hi guys hopefully i can get some direction to get our Apple IIe platinum (607-0288) International NTSC back to life.
Was in storage for a few years now when i turn it on - no beep and we get a hatch display with squares? Thick lines horizontally & vertically? Trying to run self diagnostics we get PP randomly with again a hatch pattern but with characters?
Power light is on
HAL 16R8CN chip gets hot?
Replaced CPU with a spare known working - no change
Anyone have any idea what we need to look at to get it back to life?
I have been advised to replace the two ram (TMS4464-15NLA) which are soldered in so will not be easy , before I order replacements anyone else have any other tips to investigate?
Thanks
Make sure the keyboard cable is connected properly. If it isn't a //e will get stuck in the self test.
Hi yes tried 2 keyboards, both same result.... the screen did change slightly a few times and the red motherboard led light up briefly as indicated previously with lower case pp followed by 2 square graphic and repeated itself to fill the screen will upload photos ..
https://i.ibb.co/GCk8Jkf/F208569-F-2415-43-AC-BAD9-340-E2-CD15-C81.jpghttps://i.ibb.co/zrcgCmL/3-C8-B7971-AB5-D-40-CE-9-D5-C-4544-BAD2-E123.jpg
Have you metered the power supply yet? That's usually the first thing you should do. Incorrect voltages will cause all sorts of failures.
Have tried a spare power supply (known working) still get the same result, but will check output again, Sadly dont have a scope to test further so will try piggy back ram first once the new dram arrives as I dont have any 464 spares so will report back. I cant remember where I saw the exact same display reported by another person who reported that it related to dram failure...