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NeXT Megapixel Color 17 Repair

 
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brooklyn



Joined: 07 Sep 2016
Posts: 2

PostPosted: Wed Sep 07, 2016 8:59 pm    Post subject: NeXT Megapixel Color 17 Repair Reply with quote

Hi, I have a NeXT 17" Color Megapixel display that was included with a nextstation I bought. The monitor was sold as not working.

When I got home and tried it, I heard the CRT energize, but immediately some magic smoke escaped, so I quickly turned it off.

On disassembly I found some cooked components on what looks like the video out board. See pictures. I ordered replacement components to solder on, but I wonder if another issue caused these components to go out?

Any ideas? Question Will update when I have a chance to replace the burnt components later this week.


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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Wed Sep 07, 2016 9:24 pm    Post subject: Reply with quote

I think it's likely if you just replace those components and power it up you will blow the new ones as well. I have no idea as to the full purpose of this board, but as I see it, each signal (RGB) has a cloned set of circuitry. Knowing that you should be able to check the values and compare across the components even in circuit to get a general idea of what else could be failing. I would immediately suspect the electrolytic cap of drying out and shorting. Secondly I would be suspicious of those transistors, followed by the diodes.
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crispin



Joined: 05 Jun 2014
Posts: 6

PostPosted: Thu Sep 08, 2016 10:47 am    Post subject: Reply with quote

I believe NeXT sold two kinds of 17" monitors. One was a Sony and the other was Hatachi. The Hatachi monitors were horrible and failed frequently. I myself went through 2 of them in the 90s.
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brooklyn



Joined: 07 Sep 2016
Posts: 2

PostPosted: Mon Sep 12, 2016 10:15 pm    Post subject: Reply with quote

I think it is an Italian monitor. I replaced the damaged components and now the monitor turns on, however there is no horizontal or vertical sync. It's either the video in board that I repaired earlier, or a problem on the deflection board. I inspected both boards visually and there is nothing obvious.

Any tips? Does anyone have any spare boards from Megapixel Color 17 monitors?



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Rob Blessin Black Hole
Site Admin


Joined: 05 Sep 2006
Posts: 597
Location: Ft. Collins, Colorado

PostPosted: Mon Sep 12, 2016 11:42 pm    Post subject: Reply with quote

Great effort , I sent you a PM. Best regards Rob
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303-741-9998 Serving the NeXT Community since 2/9/93
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