Apple II problems

My apple II has been acting up lately.

Ooooh, a non-plus. Yeah, so, there's no hope for it. My mailing address is...

Take a look at this newsgroup thread, which contains a lot of ideas on diagnosis, and focuses on the II (non-plus):
http://groups.google.com/group/comp.sys.apple2/browse_thread/thread/3f9c0fa21f4a0123/675c8a657ba68677#675c8a657ba68677

The newsgroup link I posted earlier has a lot of diagnosis information buried inside it. Below is an excerpt that may be of use to you:

schmidtd wrote:
> I had a different kind of video problem with a board of mine.
> But like you, I saw some real characters. So I figured the
> video circuitry was good, so was character ROM, so was at
> least some memory, and the CPU was probably ticking too.
> I also went through the process of swapping and testing each
> and every socketed IC. No dice. Mine turned out to
> be one of the transistors - the 3904 between A and B, 12 and 13.

> I'd replace the transistors on the board. Desolder and solder
> in new parts. You can get them from Radio Shack or Jameco.

That is the transistor that drives the /RESET line. It is the perfect candidate in this case.

CHECK /RESET !

First unplug the keyboard cable connector and then check the voltage there (in the keyboard connector, on the MLB, with the keyboard cable unplugged) between pins 8(GND) and 3(/RESET) :
1---v---16
2- -15
red tester probe here-->3- -14
4- -13
5- -12
6- -11
7- -10
black tester probe here-->8-------9
[Editor's note- sorry, I can't get the little ascii graphic to format correctly with BBCode]

If there are (close to) +5v, jumper (short) somehow pin 8 with pin 3, to manually "feed" a reset. If it still does not work, the problem is likely somewhere else, nor related to /RESET. Well, you should first check too for continuity between pin 3 on the MLB keyboard connector, and pin 40 on the processor, just to make sure that the 6502 is getting the /RESET too.

If there are 0.x volts, then the transistor is most likely bad, or it is being (badly) driven on by the power up reset circuit, the 555 at A13.

To check the transistor without removing it, first remove the 555 at A13, then jumper somehow pin 3 to pin 1 on the now empty 555 socket at A13. Turn it on and check again the voltage in the keyboard connector (as above), it should be (close to) +5V. If it is 0.x V, the transistor is most likely bad. I say most likely because there remains the possibility of a short in the /RESET line, somewhere else. BTW, if you've got some business cards nearby, insert one in each slot connector, just to make sure they are not shorting. I've seen more that one Apple II with the pins bent inside the slot connector, shorting inside the connector with the pin just in front of it.

If you feel the transistor is bad, remove it by first cutting the legs, connect everything in place and try to make the Apple II work by manually feeding a /RESET, this time from the RESET key on the keyboard. This way, without a reset circuit, it's more like a real original Apple II, I think.

It's of no use to check any further without making sure first that /RESET is not stuck low. So let us know... GOOD LUCK !

Hi,
I have always used micro screw drivers, or the dental tools that I would buy at a HamFest in the past.

Always, take your time. Pry a little at a time. Try to pry from both ends once you start if you can.

Take Care,

Just use a small flathead screwdriver. Pry up a little bit on one side of the IC, then move to the other side. Keep going back and forth and you will be lifting the IC out of the socket without bending the pins.

Chris

Hi all

I just recently picked up a Free Apple IIE but when I power it up I do see the familiar APPLE ][ at the top of the screen, I rescued this Apple IIE from going to the landfill.

If I boot from Dos 3.3 Prodos or just simply press CONROL + RESET
and get to a cursor the cursor keeps scrolling to the left on its own.

No none of the keys on the keyboard arent stuck at all.

I grounded myself on the power source and then pressed lightly on each IC to reseat them in their sockets.

BTW on this Apple IIE all chips are socketed.

What IC could go bad that could cause this behaviour?

I noticed on the Motherboard where you plug in Joysticks and paddles, there is a black square IC there, it says on top of this IC Game I/O.

I also checked the ribbon cable that goes from the keyboard down to where it plugs into the Motherboard, this connector is keyed so it cant be plugged in wrong, and the connector was plugged in all the way.

I assume this must be some sort of IC or Motherboard problem.

I also took out the printer card, the disk drive controller card, still have the same scrolling, so it wasnt either of these cards that could be bad or malfunctioning. Of course I turned the power off before I removed "any" of the cards from the slots.

I noticed that if I pressed any keys like "A" then the cursor would still scroll A's across the screen, or any other character does this.

When I was in High School I used Apple II computers and never had this happen.

I attached a disk II 5.25 drive and that works just fine with no problems, will boot Dos 3.3 disks and Prodos.

Whenever I ran any software though because of the cursor scrolling this would make it hard to make selections and so forth.

Any suggestions?

Hi,
You should have started your own question. I beleive that the problem is in the return key being stuck. Not the physical part tha goes up and down but the contacts inside the keyswitch. Now I am not sure if it is the "return key" the "space bar" or the "shift keys".

By hitting the key a little harder than normal over and over again like a wood pecker may help free up the contacts. I mean more like 400-500 times in a row. The computer does not have to be on. If that does not work, then the next trick is to remove the key cap. I use a large paper clip and make like lok like 2. LLs or the bottom half of a stick man. Have to be able to pull it straight up and even, from at least 2 sides. With it removed and a pair of small needle you want to work the bad key like you did before. But this time you want to pull up on the up stroke. Tricky, since you have to do it with a little more force than the return spring, Doing it straight and fast. You do not want to bend the stem or grip it so hard you damge it. As I said it is a bit tricky.
I have done this a couple of times and it has worked. But I am sure there are times when the key switch has to be replaced.

Take Care,
George

[quote=Excuse me if I started this quote wrong:
Hi George: Yes, you pull Commodore 128 keys off in the same way, I completely cleaned up a C=128 keyboard pulled off all keys & springs, cleaned PCB and contacts and put it all back together, after that it worked like new. (was done for a C= friend).

I asked another source about this problem and they mentioned that it had to be KB contacts or something under the key or just plain "dust" which this AppleIIE had been sitting in a shed for many many years collecting dust.

So I can get all the keys back in order I could take a picture of the keyboard "layout" with my digital camera or make a diagram.

I also noticed on the Motherboard towards where the Paddles and Joystick plug into, I saw printed on the Motherboard "Game I/O" Does this component drive whatever is plugged into the Joystick/Paddle port?

I also saw an IC chip and it is labeled on the Motherboard: "CD ROM" does this mean I could use a CD-ROM drive or possibly Hard drive or SCSI drives with this Apple?

Thanks for all of your suggestions and help.

Take care,

-Terry

Twilight_Rodent]Hi,
You should have started your own question. I beleive that the problem is in the return key being stuck. Not the physical part tha goes up and down but the contacts inside the keyswitch. Now I am not sure if it is the "return key" the "space bar" or the "shift keys".

By hitting the key a little harder than normal over and over again like a wood pecker may help free up the contacts. I mean more like 400-500 times in a row. The computer does not have to be on. If that does not work, then the next trick is to remove the key cap. I use a large paper clip and make like lok like 2. LLs or the bottom half of a stick man. Have to be able to pull it straight up and even, from at least 2 sides. With it removed and a pair of small needle you want to work the bad key like you did before. But this time you want to pull up on the up stroke. Tricky, since you have to do it with a little more force than the return spring, Doing it straight and fast. You do not want to bend the stem or grip it so hard you damge it. As I said it is a bit tricky.
I have done this a couple of times and it has worked. But I am sure there are times when the key switch has to be replaced.

Take Care,
George [/quote]

Hi,
If you have to replace a Key Switch, I beleive there are 2 kinds. Long throw and short throw. I guess they have to do with how far it goes down or sticks up.

Yes the I/O is for 16 pin devices, paddles, joystick or sensors and such. On some IIes I believe you could also plug into the back with a DB-9 if they had a port. Not at the same time.

On the CD rom was just a way to ID the chip. I do not think CDs were even out then.

You can use a certain SCSI drives if you have a SCSI card for the apple.

They do make, and sell a CFFA card for all of them like a solid state HD on a card.

Take Care