IIe Platinum Video problem

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6502enhanced's picture
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Joined: Feb 23 2006
Posts: 252

Hi,

I got my first Apple IIe Platinum. I got it for a good price I think (60$). Inside were also a 5.25 controller card and a SSC. That's all very nice.

What is not so nice is the fact that it has a video problem.

When I turn it on I get this picture:

After typing ctrl apple reset I got this:

After typing that again the first appeared again. After a while only the first picture appears and nothing else happens if I type ctrl apple reset ...

I tried the following chips from an Apple IIe enhanced (normal not Platinum) without success:

MMU chip
CPU
Video ROM
Keyboard ROM

also tested the following IC's:

SN74LS10N
74LS245WP
74F109N
342-0170-A

What could be the problem?

Thanks for any hint!

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Joined: May 9 2010
Posts: 11
Re: IIe Platinum Video problem

However, a 74LS10 is not intended for IIe boards.

6502enhanced's picture
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Joined: Feb 23 2006
Posts: 252
Re: IIe Platinum Video problem

I do have an Apple IIe enhanced and this Apple IIe Platinum - on both boards is a 74LS10N.

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Joined: May 9 2010
Posts: 11
Re: IIe Platinum Video problem

Relevant is the designation on the silkscreen. Schottky-TTL types provide more output current and speed. I have never seen before boards with LS10.

speedyG's picture
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Joined: Nov 16 2011
Posts: 2406
Re: IIe Platinum Video problem

At //e ->
Self Test => Ctrl + Closed_Apple + Reset

SpeedyG

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6502enhanced's picture
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Joined: Feb 23 2006
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Re: IIe Platinum Video problem

Hi Speedy,

thanks - yes, I've done the self test (on the Platinum Reset,Ctrl, open Apple and Option) but there happens nothing while doing that. The screen is like the first picture of the monitor above.

Meanwhile I only get the first picture of the monitor - the second one does not appear anymore. I suppose that the faulty chip is now really faulty Smile

So far I've tested all chips on the board that are not soldered except the CF ROM which I'll have to order.

But before I'll do that I ordered yesterday the two RAM chips.

I'll post what happens ...

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Joined: Apr 14 2006
Posts: 39
Re: IIe Platinum Video problem

My first thought is - have you checked the power supply? These tend to be one of the main area's of failure in any old computer.

Lot's of weird behaviour is possible if your PSU is out of spec.

If you have access to a different //e PSU, I would recommend trying it with your board before doing anything else.

6502enhanced's picture
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Joined: Feb 23 2006
Posts: 252
Re: IIe Platinum Video problem

Thanks! Yes, I've tried a known working PSU - the same.

The ordered RAM chips should arrive in the next days ...

Is it ok to piggy-back them for testing on the old? If yes should I solder them on the old? (Never done that ...)

speedyG's picture
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Joined: Nov 16 2011
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Re: IIe Platinum Video problem

6502enhanced wrote:

Is it ok to piggy-back them for testing on the old? If yes should I solder them on the old? (Never done that ...)

Never !

Unless you want to kill more chips.

SpeedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

6502enhanced's picture
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Joined: Feb 23 2006
Posts: 252
Re: IIe Platinum Video problem

Ah, ok - thanks!