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NeXT 17" Sony Trinitrom Color Monitors power up but no

 
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Rob Blessin Black Hole
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Joined: 05 Sep 2006
Posts: 679
Location: Ft. Collins, Colorado

PostPosted: Tue Jun 12, 2018 12:06 pm    Post subject: NeXT 17" Sony Trinitrom Color Monitors power up but no Reply with quote

Hello NeXT Community: I have 2 NeXT 17" Sony Trinitron Monitors , cosmetically they appear to be in perfect condition , the power lights up and I here a hum but no picture on either screen with either a Turbo Color or Dimension board . To verify it was not cabling or the systems , I hooked up a flat panel and it comes right up.

I've tried all the adjustment knobs on the front , I was told they both worked. They were packed well so I don't really want to recycle them as I'm sure a lot of the boards are good and seeking advice as may be some has had the issue and successfully repaired them. I have completely disassembled them before they are well thought out and easy to look at and

I know I can look for roasted components . I thought if someone can use them and wants to cover ground shipping and may be a packing fee a good box and bubble wrap , I'm think around $100 total in the US each . One or both are yours. I also probably list on eBay and explain the problem as they would make for a nice prop display . Any thoughts? Are there any fuses I know on FIMI's there are ? Also I don't want to get jolted as I know they can pack a bunch even when unplugged .....
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barcher174



Joined: 07 Dec 2012
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PostPosted: Tue Jun 12, 2018 2:56 pm    Post subject: Reply with quote

I seem to recall that next dual sourced these (toshiba and sony maybe?) and one of the models was known for poor reliability. Caps are always a possibility, but there may be some design flaw at work.
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Rob Blessin Black Hole
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Location: Ft. Collins, Colorado

PostPosted: Tue Jun 12, 2018 10:58 pm    Post subject: Reply with quote

The Phillips Fimi reportedly had more problems but believe it or not Iíve had better success with them. All these monitors are approaching 30 years so Iím guessing component failure probably caps. I find the flat panel solution much easier to handle obviously so I guess itíll be last call for these 2 . I did post them on eBay no reasonable offer refused lol .
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pentium



Joined: 23 Jun 2006
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PostPosted: Thu Jun 14, 2018 5:45 pm    Post subject: Reply with quote

I know with the 21" hitachi units a capacitor replacement helps (I know the SGI models had an internal fan so they were less prone to drying out) but when it came to Sony 17" monitors of that era I found that the monitors were getting smart enough that if it thought the B+ or anode current was too high it would shut the high voltage down. Usually it was a capacitor issue as well but I've seen one or two monitors where it turned out to be a faulty flyback. My only guess for those two was failure of the epoxy potting allowed moisture into the windings.
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Rob Blessin Black Hole
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Joined: 05 Sep 2006
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Location: Ft. Collins, Colorado

PostPosted: Fri Jul 06, 2018 12:57 am    Post subject: Reply with quote

I think I found the problem in monitor 1 lol
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Rob Blessin President computerpowwow ebay sales@blackholeinc.com http://www.blackholeinc.com
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barcher174



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PostPosted: Fri Jul 06, 2018 1:50 am    Post subject: Reply with quote

I'm sure that'll buff right out...
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Rob Blessin Black Hole
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Location: Ft. Collins, Colorado

PostPosted: Fri Jul 06, 2018 2:43 am    Post subject: Reply with quote

On Monitor 2 , I disassembled to where I was able to visually inspect all the boards and components. I didn't see anything jump out at me.... but I did find yes these Sony trinitron do indeed have a fuse!
I'll be damned so please note I let these sit for a few weeks as they can pack a punch even if sitting for a while and being unplugged and was very careful not to go poking around to much , rumors it can be 20,000 volts ouch .
That being said They are relatively easy to disassemble 4 screws hold on the shell and various protective cages cover the inner boards , undo a dozen screws and you can see everything internally .
For further dissaembly You can carefully , simply unplug the connectors for example on the power supply board left side looking at from the back and it hinges next to the monitor lift and separate away. .

The protective cage for the power supply is easily removed with 2 more screws and then you can see the power supply board free and clear of the monitor , the fuse for your Sony is hidden in plain site and is located right by the power connector for your power cord plugin only way to get at it is disassembling the cage and pulling the power supply assembly .....

gee on the Phillip's FIMI NeXT monitor the fuse is easily accessible from the out side ,

the trinitrons , I find out 30 years later lol, wonder how many times a DOA trinitron would have just been a blown fuse , now we know. The fuse looks good.

So I'll try it in the morning as I'm hoping it was just a loose connections way late again. I'll try an add photo's to this thread.....

so monitor 1 goes to the recycler , I'll save the good "boards" out of it , in case anyone needs one.

The adjustment tool is also on the cage which will come in handy.








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