I've got a IIe with logic board part number 820-0064-C. It appears to be a non-enhanced version.
When I hold down the apple keys and power on, it shows "RAM:" and sits there. ONE time I was able to get "RAM: F13 F12 F11 F10 F9 F8 F7 F6", but that doesn't much make sense. I can't get anything to boot properly either. Comes up to the Apple ][ display and the BASIC prompt but won't boot anything off of disk completely.
Has an 80 columns card and a Z80 softcard. It knows when the softcard is and insn't installed (when I try to boot CP/M it will say its not there, and if it is there, the system doesn't complete booting). I also can't get it to boot any native software. It starts reading the disk, then just hangs.
Any suggestions on how to further test this thing? I know I'm already running the Apple II+ project mentioned in another thread, but I picked this IIe up along with some other parts and a monitor for $200 and am trying to gather information while I'm working on the II+ separately.
Thanks all!
Chris
RAM failures are common on //e, especially if you have MT brand RAM. Early motherboards are socketed, but most are not. Usually the self test will identify bad chip(s), but not always. The Enhanced self test is a little better than the original one. If you could get anything to boot I'd recommend something like XPS Diagnostics, the MECC diagnostics or the Apple Dealer Diagnostics.
You can find those here:
https://mirrors.apple2.org.za/ftp.apple.asimov.net/images/disk_utils/diagnostics/
It is not hard to desolder RAM chips and solder in sockets and new chips are available. However, it does require a little skill and you can ruin your board if you do it wrong.
All that said, it is also entirely possible it isn't a RAM problem at all or at least possible that's not the only problem. There are several other chips that it could be also. I'd recommend checking out one of the books on troubleshooting and repair like the ones from SAMS you can find here:
https://commodore.bombjack.org/apple/apple-books.htm
Sounds good. I've got no problem with the desoldering, I have proper rework equipment to get the job done, and enough experience with it to be dangerous.
I found some 3764-20 chips in a bin here at the house, I'll work on the machine tomorrow and do the piggyback test with them.
I'll investigate the troubleshooting stuff. I've also got a friend who's good friends with Adrian Black as well.
So it seems all of the RAM chips are Apple stamped MT 4264's except for one OKI M3764-20.
I ran the monitor program
“C050 C053 C054 C057 N 265:FF N 266<265.BFFEM 266<265.BFFEV 265:0 N 266<265.BFFEM 266<265.BFFEV 34:14 “(Return)
The Apple II will go to HGR mode and display white and dark graphic screen along with question marks and inverse @ characters at the bottom of the screen. If some RAM chips are bad, faulty addresses will be printed on the bottom of the screen.
And it essentially spits out that all of the RAM is bad. I tried a piggy back chip one at a time on each chip and no avail. Self test just shows "RAM:" and nothing else.
Any suggestions?
At this point I think I'd desolder all 8 RAM chips and solder in sockets and start with a fresh bunch. A lot of people would say all those MT chips are ticking time bombs to fail anyway even if they haven't yet. Anyway, if that doesn't do it then at least you know what it isn't, and you can start checking other components that can cause RAM errors.
If you don't want to just jump in the fire like that, you coudl do one chip and see if it makes any difference, then decide how to proceed after that.
That thought had crossed my mind. Socketing all of them seems like something wise to do anyway. It is unusual (or is it?) that one of them is an OKI 3764-20, the others are all MT. It doesn't appear the board was reworked where the OKI chip is, and if it has been, they did a heck of a job.
Chris
I've seen factory boards with mismatched chips before. I've also seen rework done by people so well it is hard to spot. So it could be either.
Well some good news finally. Replaced all of the RAM chips with sockets and that enabled me to swap things around with ease, and, of course, I found a bad Apple branded MT 4164.
All of the ram chips are now brand and speed matched OKI chips. Somehow I had them in a bin, much to my surprise. Probably came out of some old IBM system when I was a kid.
Self test results in KERNEL OK now. System boots software using known good disk drives from the Apple II+.
Looks like both disk drives that came with the system need attention. I hear a loud scraping noise from within them when the disk is spinning and they don't boot software. I can tell at least one of them needs a belt replaced, but it doesn't appear to seek the heads at all. I haven't opened up the other one which has the major scraping sounds.
I'm told from multiple sources that these drives SHOULD NOT be lubricated no matter what, so I'm heads up on that if that's the case.
Chris
Glad to hear it is working now. If you ever have another bad RAM chip it will be easy to fix at least. You only have the pain of desoldering once.
As for the drives, the first step is a thorough cleaning. Most of the time that is all they need. As you've heard, they generally don't recommend lubricating things, at least Shugart didn't. Apple generally used either Shugart on older Disk ][ drives and sometime they switched to Alps because those were cheaper. I think pretty much all the Unidisk 5.25 and Duodisk and Apple 5.25 drives are Alps.
So I cleaned the drive, but adjusting the speed control on the back it seems like I can't get the 60Hz strobe wheel to do its thing. The speed of the drive defintiely changes, but the strobe wheel never "stops" if you know what I mean.
It doesn't run all the time (put a controller in slot 6 and this drive on a controller in slot 5 and it doesn't run like you'd expect with a bad LS125.
Curious what all it could be. It is a Shugart mechanism. the "head banging" is very, very soft on this drive compared to others.
Well, I got the Floppy Emu and that thing is absolutley incredible. Took no effort at all to load every diagnostic program I could find onto the SD card, and then the machine.
So the IIe passes every test I can throw at it from multiple diagnostic programs. I'd say that's a wrap. Waiting on a 74LS166 (had to borrow one from a Videx card).
Disk drives remain a project I haven't touched yet, but now can since I can get diagnostic software running!
Chris