Problem z Apple IIe

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Problem z Apple IIe

I would like to say hello :)

I have a problem with apple iie. I have this image on the screen.

https://i.imgur.com/AIxqp61.jpg

https://i.imgur.com/ynNWoii.jpg

I checked the power supply. The voltages are correct.

I checked the capacitors. There are no short circuits.

Using the TL866 programmer, I checked the 74xxxxx circuits

The test failed: 74F09,74F10,74LS175,74LS74.. I replaced

The replacements pass the test.I replaced the processor pulled from the 1541 station and two from aliexpress ... no changes

I connect the computer with and without a keyboard.

I tested the RAM with the arduino tester :) three bones are damaged ... I replaced the whole set.I reprogrammed  video rom.I replaced 341-0170 (managed to buy it at a bargain)I'm running out of ideas.

 

 

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Hopefully it isn't a bad IOU

Hopefully it isn't a bad IOU or MMU chip, those are basically unobtanium.  If those are bad your only realistic option is to get another motherboard and it may be easier to buy a whole other //e unit.

 

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Does it pass self test? open

Does it pass self test? open-apple + closed-apple + ctrl + reset?

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It doesn't look like the

It doesn't look like the video is working enough you could see if it was even running self test.

 

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Do you get a beep when you

Do you get a beep when you switch it on and if no, do you have an oscilloscope?

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CVT pisze:Czy po włączeniu
CVT pisze:

Czy po włączeniu wydaje sygnał dźwiękowy, a jeśli nie, to czy masz oscyloskop?

 

Yes, I have an oscilloscope. The speaker does not make any sounds ... sometimes a slight knock

 

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jeffmazur napisała:Czy
jeffmazur napisała:

Czy przechodzi samotest? otwarte jabłko + zamknięte jabłko + ctrl + reset?

I haven't tried connecting a keyboard. I read somewhere that without the keyboard the test is automatically called.

 

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That is true. This is what

That is true. This is what you get if you unplug the keyboard cable of a working Apple IIe: https://youtu.be/igii1OIWw7Y

 

I am curious though: how is it that you have so many damaged chips in one machine? Usually it’s just one or two. Was it used for parts? Is there any physical damage on the motherboard itself?

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You said you replaced the 341

You said you replaced the 341-0170 HAL/PAL Timing generator. Where did you get that and are you sure it is programmed correctly?

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jeffmazur wrote:You said you
jeffmazur wrote:

You said you replaced the 341-0170 HAL/PAL Timing generator. Where did you get that and are you sure it is programmed correctly?

 

That's a really good question...  There are a few places that sell them....  the one I would normally recommend is ReActive Micro.

 

https://www.reactivemicro.com/product/upgrade-gal/

 

 

 

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CVT wrote:That is true. This
CVT wrote:

That is true. This is what you get if you unplug the keyboard cable of a working Apple IIe: https://youtu.be/igii1OIWw7Y

 

I am curious though: how is it that you have so many damaged chips in one machine? Usually it’s just one or two. Was it used for pa

 

 

That's a really good point...  Personally I don't really trust the chip test features of most of the inexepensive USB chip programmers...  But even that given, I've personally never run into a //e motherboard that had more than a couple bad chips on it either.  If the number the OP posted were really bad I'd also be really suspicious that it was someone's spare parts board and it may be something that is almost not worth trying to fix.  As previously mentioned if the IOU or MMU are bad...  it is almost a lost cause.

 

 

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Janusz wrote:Yes, I have an
Janusz wrote:
Yes, I have an oscilloscope.
...

 

Right, so I would start by checking all the oscillograms on page 51 of SAMS ComputerFacts - Apple IIe (with the keyboard plugged in),  starting with the one on pin 37 of the CPU.

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CVT pisze:To prawda. Oto, co
CVT pisze:

To prawda. Oto, co otrzymasz, jeśli odłączysz kabel klawiatury działającego Apple IIe:  https://youtu.be/igii1OIWw7Y

 

Ciekawi mnie jednak: jak to się dzieje, że w jednej maszynie masz tyle uszkodzonych chipów? Zwykle jest to jeden lub dwa. Czy był używany przez pa

I bought a complete computer (Station, 2x fdd, monitor) looks never opened. It was definitely not soldered.

Has been sitting in a shed or garage for a long time. There are no traces of rust. I think it was in dry conditions.

 

I bought the GAL chip at a bargain on a local auction site for $4  https://i.imgur.com/cVfKDEX.jpg

 

I also approach the testing of 74xxxx circuits with reserve. But the new circuits programmer shows as good.

 

IOU lub MMU and 6502  They are warm but not hot.

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The IOU and MMU may still be

The IOU and MMU may still be bad even if they aren't getting hot.  GAL may be good but who knows when it comes from an unknown source.

 

I would follow those troubleshooting guides that CVT pointed you to.  If that doesn't work then the easiest way to get something working may be to buy another motherboard or main //e unit.  Then at least you'd have spare parts.

 

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