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ussexplorer

Got the apple II and this it he pic of the display issue.

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So have the three pics of the display issue. One is on power on, the other is on ctrl reset. then the final is when I type you can see if move around. In fact It beeps at me. So I'm pretty sure it is posting and going into basic. Just picture looks all lined up and such. Played around with the ram.Removed all the cards. etc. etc. Any idea on what to start at.

Oh and for more pictures of the computer itself. I have it posted on APpleFritter via user NovellNetware.

Thanks,


Josh

boot issue after ctrl reset0003.JPG

boot issue0001.JPG

boot issue0002.JPG

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ill add in try it on a different screen, its just a composite video output nothing special 

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Posted (edited)

I did play around with the memory chips. But I wasn't sure what bank was used for video. Plus I noticed some gunk on the pins. So I need to clean that. Well gunk but now all the way down into the sockets. I also need to bust out my volt meter too. But I did remove all the cards. Even the 16k expansion and placed one of those chips in the socket. I removed all memory and got no beep.  So I'm like okay. I'll keep putting memory back in until I get a beep and see if I get any difference at all. I honestly with I had the memory test I used 20+ years ago for the shop I worked at. Simple dram tester. Oh and yes all the chips are original apple stamped memory chips. Also yes. I was thinking of plugging a vcr into the motor. But from my understanding. That is the monitor that came with it.

Edited by ussexplorer
added more informaiton.

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9 minutes ago, Osgeld said:

ill add in try it on a different screen, its just a composite video output nothing special 

just put the monitor on a vcr. Besides the Height needing adjustment. Works just fine for picture.

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1. Tried Monitor on vcr. Works fine.

2. Remove all cards

3. Remove mainboard from case

4. check powers supply. All volts are good. Well two volts was just a tad under what they should be.

5. Removed all memory chips except first row closet to keyboard.

6. Take all memory chips from Microsoft 64 k upgrad card and put them in first row.

7. Swap chips around that matched.

8. Removed and reseated almost all chips.

9. Only tarnish found was on original apple memory chips. But only so far down. Not all the way into the socket.

10. Removed apple special rom. Just got a big black green screen. (Assume this is normal.)

11. 820-0044-d apple 2 main logic board rf1 (thus no memory jumpers.)

12. inside of case is stamped march 1982

Oh and one more thing. When I keep pressing return. It keeps beeping and the picture keeps changing. This is after pressing ctrl reset. I also check the bell on the keyboard and it does beep. So I'm pretty sure it is booting. Just not giving me a picture. LIke one of the switching ic chips is busted.

 

Thanks,

 

Josh

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Posted (edited)

can you enter graphics mode

 

GR

return

 

could be ram (kind of doubtful) or something to do with the ram interface 

could be rom

could be the video shift register 

 

have you pulled the motherboard and looked for rotten traces? 

Edited by Osgeld

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Well yes. I do have the motherboard out and I didn't see anything falling off but I did see the following. I don't know the term for it. Underneath the cover is started to bubble? But I checked it and nothing came off. I have had sometimes when you rub a area. it will come off and you have to put on a jumper wire. But this is pretty bad and I don't know if it hurts anything. So I attached more pictures. So you can take a good look at it. I'll have to try the JR and return Saturday when I get home from work. Right now it is in a safe pile so I can clean the case. I guess you could call it Rotten. But my idea of rotten traces is like battery corrosion and stuff.

 

Thanks,

 

Josh

applboardftont0003.JPG

applboardback0001.JPG

applboardback0002.JPG

applboardback0003.JPG

applboardback0004.JPG

applboardftont0001.JPG

applboardftont0002.JPG

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Okay. So I tried the gr command.

 

1. press ctrl and reset

2. gr

3. return

 

Get blank screen. Only difference I noticed is now no matter how many times I press enter. I have a blank screen. If I do not use that command. I get lines in different spots on the monitor or not lines at all.

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Posted (edited)

k, get back into basic

 

GR (return) 

COLOR = 9 (return) 

HLIN 0,39 at 10 (return) 

 

see if you get a line on the 10th row

Edited by Osgeld

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Posted (edited)

or

GR (return) 

COLOR = 9 (return) should be orange on a color monitor)

HLIN 0,39 at 20 (return) 

VLIN 0,39 at 20 (return) 

 

should draw a cross in the center of the screen 

 

please note I have not delt with apple II hardware faults or apple II in general in like 5 years now so I am just shooting from the hip (grew up with them, had a collection, moved on to machines I didn't have) 

Edited by Osgeld

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Okay I put everything away tonight after swapping a bunch of chips around according to another site. Still same thing. So when I have a sec on sunday. I'll see if I can set it back up and try typing that in. See what I get. I also checking some additional random points around the board for 5v and such. But I'm running on what I call board level repair. I only have very, very limited experience. Soldering, chip removal and volt meter (to a point.) is not an issue. But I don't have o scope or really know how to read a complex diagram.

 

Thanks,

 

Josh

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Just wanted to post a small update. I have not done any hardware stuff today. But I was reading through the apple ii official diagnostics. I'm surprised about how much is just replace a chip or check with a volt meter. When I first started in computer around 1992. I always figured it was a hack thing to do. As time passed on. I got better at locating and reading what part of the board does what. So that narrowed down the search during a repair. i remember towards the end having it down pretty good for certain fixes. The biggest problem being in a small town (even the next town over.) didn't have a place you could just go in and get stuff. Well except for the Radio Shack. That was limited for parts. I considered the real people who built and used o-scopes to be the true repair people or what I call board level repair. The video I was watching on you tube explaining by the time the apple iie came around. If it wasn't a simple fix. You would just send the board back to apple and they would send another repaired one back to you. So for you guys who are trying to go it alone. Give yourselves a pat on the back.

 

TTFN,

 

Josh

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One final update before bed. I moved around all the chips I could move. Still no difference. So for now I continued cleaning the system up. I did a test with simple green and the lid. It worked great. Just like it did 20 years ago. So I continued with the top, bottom (used a paint brush) and removed the keys for the keyboard and soaked them. Talk about really clean already. I also used a paint brush on the mother board to clean the little amount of dust on it. I also posted on the local Facebook groups looking for parts. Unless I get lucky. I think I'm at the end of my talents. So I'll still try the stuff above when I get a sec. But next is cleaning the monitor, then printer (that will be a hoot to clean.) and the disk drive.

 

TTFN,

 

Josh

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Update:

Got a picture. Joined a group on face book and they asap pointed me to the right bank of chips. One suggested to swap them out in pairs. After messing around I had three results.

1. same issue

2. no picture

3. picture of APPLE II repeated several times and unable to get a scroll lock.

 

So I'm going to source out some 161 chips and see what happens.

Thanks,

Josh

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Got the chips on the way. Should arrive by Thursday. I'll keep everyone posted. Once again thanks...

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Okay so I got the new ships in. Mitsubishi 74LS161A chips. Now we have a working display and mostly a computer. I still have to clean the printer and disk drive. But now I have a great keyboard problem. I was hoping to avoid this. I'm pretty sure it is dirty. Though this machine is pretty clean. What I get is repeats, some keys not working, some keys working fine. Sometimes I have to smack it a few times. The T key don't work at all. most keys work great. Like the space bar, return, and greater or less than. To name a few. This is what I get for putting the machine back together. Now I have to open it up to pull the keyboard. So I'll keep you guys updates. But for now. This issue is resolved. I'll start a new post for keyboard stuff once I get it cleaned. Thanks, Josh

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Glad to hear you got the display working.

 

With regards to the keyboard, sometimes you can get the keys working again by applying a little contact cleaner down the key stem and working the key up and down for many repetitions (like a hundred or so). Other times you have to fully desolder the key switch and open it up to adjust/clean.

 

If the key is not working at all, like in the case of your 'T' key, I suspect you are going to have to resort to the latter option and open up the key switch. Upon opening the key switch, you may need to gently bend some of the metal contacts such that they make contact again.

 

Good luck, and let us know how you get on.

 

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