Fixing N4006 Monitor

Hello Everyone,

Since being unemployed for sometime now I have free time to tinker.  Fixed multiple machines, Altair, SWTP, etc.  Now I am working on monitors.  I have completely disassembled all of the circuit boards from the N4006 and will replace all of the CAPS which I believe is causing the monitor to power down as soon as it starts up. 

Here are some images.  Just getting started.

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Back in the early 2000s I had such a monitor, and it had the same problem. I remember finding a FAQ or a newsgroup/forum post somewhere saying that this particular model (which was used with a variety of Unix workstations, I think -- the N4006 was just a black-case version made for NeXT) had some particular part that needed to be replaced. The part wasn't a capacitor, I don't think.

I don't recall what it was that failed, but this thread about a different Trinitron (found by Googling "trinitron monitor turns itself off" matches my dim memory:
http://www.videokarma.org/archive/index.php/t-57097.html

I will replace all of the CAPS and the HSTAT device.  Here is the image of the device.

1-237-344-11 High voltage resistor assembly

You can order it from here:
https://sony.encompass.com/item/543667/Sony/1-237-344-11/

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Also here is the list of ALL Capacitors that I removed from the monitor.  I removed ALL Electrolytic caps.  Many of them were leaking of have leaked out.  Will compile this list in an excel sheet soon but here it is.  All values are in micro farad (uF) and all are Radial capacitors (have two leads which stick out from the bottom of the capacitor). One page at a time because of the size limit for images.

All caps ordered via Mouser except the 2) 250V 820UF that was Amazon.  See attached.


I included the written images and now the excel sheet showing all of the values.  Here is the breakdown.  (Number of units) Voltage uF

1) 50V 0.47UF

10) 50V 1UF
4) 160V 1UF

4) 50V 2.2UF
3) 100V 2.2UF
1) 400V 2.2UF

1) 25V 4.7UF
6) 50V 4.7UF

3) 16V 10UF
12) 50V 10UF
1) 160V 10UF

3) 25V 22UF
1) 160V 22UF

1) 50V 33UF
3) 160V 33UF

13) 16V 47UF
5) 50V 47UF

4) 10V 100UF
9) 16V 100UF
5) 25V 100UF
2) 80V 100UF

4) 35V 220UF
1) 400V 220UF

1) 6.3V 330UF

1) 10V 470UF
1) 16V 470UF

2) 250V 820UF

2) 16V 1000UF
2) 25V 1000UF
4) 35V 1000UF

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Caps page 2 plus Mouser parts list

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Caps Page 3

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Caps Page 4

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Caps Page 5

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Caps Page 6 and 7 (FINAL)

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Sony Manual that matches the N4006.  The schematics match my monitor.  Many of the caps do not match the listings so I am going with what I pulled out.

GDM-1601_Service_Manual_1988
http://www.bitsavers.org/pdf/sony/monitor/GDM-1601/GDM-1601_Service_Manual_1988.pdf

I would download this and save it!!!  Tried to upload but it is to large.

All original caps have been de-soldered.  I keep all of the old CAPS and the bag the boards with the caps so I can compare if needed to the new caps. 

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Just a quick update.  Received all of the CAPS except two values that should be here later this week.  Everything else is soldered in.  Here are some images of everything completed.  Once the final caps come in I will get it assembled again for testing.

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Well, I got everything back together and powered it up.  The good news is that the green light stays on the bad news is that I get nothing on the screen.  I do not get any static charge on the front of the screen during power up or down.  Not sure what is wrong.  I left the original HSTAT device and have not ordered another one yet. 

Anyone have this issue?

Hello Eric: Excellent effort .... I currently do not have any working Sony Trinitrons in stock. 

I have some of the internal boards for them condition unknown $20 each.

I uploaded the service doc here : http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/

Best regards Rob

Help Please ---

I drove the monitor to a old-time TV repair place about 100 miles from my house.  For $50 he spent about a couple of hours looking for issues and determined that:

1) The correct power is going into the Flyback but the Flyback is not putting out the correct High Voltage. 

He suspects that the flyback was damaged when the power supply caps eroded.  So I am trying to find the flyback.  The markings say: 1-439-533-11.

I have searched and searched and every site that sells flybacks says no longer stocked and no replacement.

So, does anyone know what can be used as a replacement?  I have spent considerable time replacing all of the caps and I would hate for this to be the final part that keeps it in its COMA.

Also I have a place about 43 miles from my house that sells all types of Flyback's but they do not have mine. 

Here is the list of flybacks they do have.  Does anyone know if 1-439-533-11 can be swapped with one of the ones below?

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Have a look at https://www.scribd.com/document/355145230/164013634-Listado-de-Fly-Back-s-Inverso-HR

If you trust that table (which I make no claims is accurate, as I know nothing of the source), an HR Diemen 80097 should be a replacement.  I've never worked on a NeXT monitor, but I have installed HR Diemen flybacks in a couple of other monitors and have found them to be good.

I have purchased them from Dönberg Electronics in Ireland (https://www.donberg.ie/), and while they do not list this particular HR Diemen on their website, they are a very friendly and helpful shop, so you might enquire anyway.  They are also quite knowledgeable and may be able to guide you toward an alternative replacement.

Thank you for this information.  I went to the website and did a cross reference and it comes back with something else????

HR 46448
http://www.hrdiemen.com/search/index?utf8=%E2%9C%93&orig=1-439-533-11

I tried clicking on more information and the page is not found.

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Quote from: Eric on January 08, 2021, 07:43:22 PMThank you for this information.  I went to the website and did a cross reference and it comes back with something else????

HR 46448

Yeah, having poked around a little more, I've also found that one cross referenced as well... and noticed the problem with HR Diemen's site.  My best advice, if you want to pursue a HD Diemen match, is just drop Dönberg an email.  They're really nice over there.

Well, I am officially stuck.  I put all of the pieces together and unfortunately the monitor is going back into the storage unit to sit.  As you can see in the email below they do not have it in stock or believe that it will ever be back in stock.

I really wish I could find an old-school TV repair person who would be willing to cheaply tinker with the monitor and try to match a similar flyback.

Oh well I tried.  I want to thank everyone who helped as well.
 

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It's crazy how quick CRT repair became a lost art considering how many years they were in production. If it were me I would keep my eye out for a cosmetically crappy Sony and see if I could do a swap.

Hello Eric: Apologies , I've been down in bed with Pneumonia since Dec 24,  it came back negative for COVID but I'm not so sure. They wanted to put me in the hospital but I chose to ride it out nd avaoid a huge hospital bill.


So I may have the parts you need here , you are just looking for the flyback transformer for a NeXT Sony Trinitron? I know I have alleast 1 DOA Sony Trinitron Monitor and a box of boards from another one.
I'm finally getting back at it . Let me look at the thread left side board with powersupply .....

Apologies which board am I looking for  :)



Best regards Rob Blessin

Its the main board that connects to the Flyback (the Red wire that connects to the picture tube).  It has lots of wires connecting to it.  Image is attached.  I also want the HSTAT (image of the white block).

Let me know what you can do.  THANK YOU!!!

Eric

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Hello Eric: I'll see what I can do please bear with me the monitor I speak of is in a crawl space, I know it is there ! Best Regards Rob Blessin

Rob any updates?

Quote from: Rob Blessin Black Hole on January 13, 2021, 01:42:02 AMHello Eric: Apologies , I've been down in bed with Pneumonia since Dec 24,  it came back negative for COVID but I'm not so sure. They wanted to put me in the hospital but I chose to ride it out nd avaoid a huge hospital bill.

Rob so sorry to hear you've been ill that long. Hoping you fully recover and feel 100% soon.

Hope everyone had a great Thanksgiving!!  I am trying to re-visit getting this working for the holidays!!  Rob any updates on any extras you might have?  Possibly I will be driving out west during the winter break and can possibly pick stuff up.  Thanks!!
Eric

My N4006 also has this problem. Seeing your determination makes me want to dig my monitor out again.
I have found a services manual here that I would like to try out.

https://elektrotanya.com/sony_gdm-1632.pdf/download.html#dl

Quote from: tt0ny on January 22, 2022, 06:59:16 AMMy N4006 also has this problem. Seeing your determination makes me want to dig my monitor out again.
I have found a services manual here that I would like to try out.

https://elektrotanya.com/sony_gdm-1632.pdf/download.html#dl

I also have an NeXT/Sony N4006 monitor with the same/similar problem.  The picture was poor - distorted colors, uneven brightness, fold-over, etc until I recapped it and now it has no picture.  I still hear the Degauss loop and CRT static charge buildup sounds and see the electron gun filaments glow, but no picture/raster appears even with the contrast and brightness turned up.  One peculiar thing that puzzles me is that it had 2 electrolytic bipolar capacitors that were not listed as such in the GDM-1632 hardware listings. These 25v 22microF capacitors were silk-screened on the little DB board as polarized capacitors (C402 and C418). I replaced them with regular polarized electrolytic caps oriented as shown in the DB board silk-screen and now I get no picture. I'm contemplating putting the original 2 caps back, but not entirely sure that was the reason for the failure.

@TUX    does your screen look like this ?

After replacing a power supply from a Sony GDM-1961 I got this picture. At least it shows a picture on the N4006 for the first time :)

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Quote from: tt0ny on February 06, 2022, 11:32:03 AM@TUX    does your screen look like this ?

After replacing a power supply from a Sony GDM-1961 I got this picture. At least it shows a picture on the N4006 for the first time :)

Thanks for the reply.  Before I recapped the boards, the picture was very poor - pretty similar to what you are showing.  After the recapping I've got no picture.  I will try looking at the power supply next.  Thanks for the help.
Tux

Yeah I also responded on FB but I think this is a cap issue.

Quote from: Eric on November 30, 2021, 09:31:08 PMHope everyone had a great Thanksgiving!!  I am trying to re-visit getting this working for the holidays!!  Rob any updates on any extras you might have?  Possibly I will be driving out west during the winter break and can possibly pick stuff up.  Thanks!!
Eric

Hello Eric: I don't know if I replied I got into the dusty crawl space finally and have a box of the boards from the Sony Trintron for you. Apologies for the delay , how about $40 covers shipping , box etc and I'll send you the lot.  According to the my pulmonologist , mri's, ultrasound and the breathing tests in something that looked like a glass phone book, I've lost 25% to 40% of my lung capacity with scaring on 2 to 5% of my lung tissue so weight loss will help and my workout for the day was getting the monitor out , I was hoping it would power on but no luck. The Boards look ok so hopefully they will help , I guess better late than never. :)

Finally got everything to work.  All of the caps I replaced were perfect!!  It was IC101 and IC102 chips in the power supply that was the whole issue.

https://www.digchip.com/datasheets/parts/datasheet/424/IR3M02-pdf.php

http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/sony_gdm-1632.pdf

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Finally got everything to work.  All of the caps I replaced were perfect!!  It was IC101 and IC102 chips in the power supply that was the whole issue.

https://www.digchip.com/datasheets/parts/datasheet/424/IR3M02-pdf.php

http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/sony_gdm-1632.pdf

IR3M02 Information

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Excellent work Eric!

Awesome job! I'm going to have to follow this for my N4006 monitor as well! How difficult is it to source the parts?

How were you able to narrow it down to those ICs out of curiosity?

Quote from: TristinAEvans on August 02, 2022, 12:21:33 PMAwesome job! I'm going to have to follow this for my N4006 monitor as well! How difficult is it to source the parts?

Hello Tristin: Welcome aboard :)  On page one of this thread Eric has a nice list of components at the time they were available at mouser pre or early pandemic as this has been a cool project to watch develop with success finally,  Eric stayed with it kudos ! :) 

On this forum software ; a lot of threads you will see the pages lower left on my browser using Mac OS ,   so you can toggle back to the beginning of  any post and watch it evolve. I'm confident you have done this before lol but good info for new members joining in we welcome all of you.    You will find a few of the legendary threads like for Previousour homebrew 68K  emulator span a decade in the making , epic stuff imho.   I know the members will truly appreciate some of the master work you are creating , quality repop much needed 3d parts for NeXT hardware. A prime example is the NeXT Sound box faceplate ,  you are manufacturing for us.  You should be able to see the attachments now as well I checked with Nitro:)  Cheers

Parts are available - Search the various Electronic distributors.  In the first handful of pages I listed all of the CAPS I used.  Every Cap from small to big was replaced.  They all worked!!

Quote from: barcher174 on August 02, 2022, 03:58:44 PMHow were you able to narrow it down to those ICs out of curiosity?

Before I re-capped everything the fuse would blow.  Found this article that talked about what can go wrong. He states "The most common failure is the switching transistors themselves".  So I said let's go for it.  Got the parts on Ebay.

https://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=info&page=psrepair.txt

Power Supply Failures

I have found that there are only a small handful of components that fail
in switching regulator power supplies.  The most common failure is the
switching transistors themselves.  The transistors short-circuit, causing
massive amounts of current to be drawn across the transformer and blowing
the fuse.

Transistor failure is often caused by bad capacitors.  It is extremely
common to find output filter capacitors that are swollen or leaking.  Any
capacitor that appears to be bad should be replaced.  To prevent a
recurrence of this all-to-common failure, output filter capacitors should
be replaced with special "low ESR" (Equivalent Series Resistance)
capacitors.  These capacitors are specifically designed to handle the
rigors of filtering in a switching supply.  Most power supply
manufacturers do not install low ESR capacitors as original equipment
because they are somewhat more expensive that conventional capacitors.
However, it is well worth the money to use them as replacement components
as they will greatly extend the life of the power supply in the field.
When I work on a power supply, I replace all the output filter capacitors
with low ESR caps regardless of whether they appear to be good or bad.
Since a service call costs far more than the capacitors, it's a prudent
thing to do.

I'll have to open mine up and test the caps on the power supply board. Even if they work I think I'll replace them all just so they're good for a while. 🙂 I found the chips you replaced on eBay as well so I bought a pair and hopefully I can get mine up and running too!

This is so exciting as usually these Trinitrons are left to die!

This exciting! I'll have to open mine up and swap out all the caps on mine. I've seen so many failed attempts at repairing these Trinitron MegaPixels and they all failed. So to finally have a successful attempt is so reassuring!

Hope you get it working again!!!  It only took me a couple of years!!!

Quote from: Eric on August 01, 2022, 10:01:53 PM

Great Job Eric!  how you fix this issues ?

Look at post #59

Quote from: Eric on August 16, 2022, 09:34:11 PMHope you get it working again!!!  It only took me a couple of years!!!

Hey Eric, I just opened mine up and it looks like mine has the same issue: there's corrosion all over the two chips. So I ordered mine and they'll be here soon.

This may be a stupid question, but how in the heck do I remove the daughter card they're on from the main power supply board??

I simply un-soldered all of the pins holding the boards in place.  Get a good desoldering tool.  I got this one and it makes the job EASY!!

American HAKKO FR301-03/P ESD Safe Portable Desoldering Tool with Precise Temperature Control °F /°C

https://www.amazon.com/American-HAKKO-Products-FR301-03-Desoldering/dp/B07BFVFMS9/ref=sr_1_5?crid=W0ZX7ZDCJBKB&keywords=desoldering+gun&qid=1661739796&sprefix=desolder%2Caps%2C115&sr=8-5&ufe=app_do%3Aamzn1.fos.ac2169a1-b668-44b9-8bd0-5ec63b24bcb5

Quote from: Eric on August 28, 2022, 09:24:01 PMI simply un-soldered all of the pins holding the boards in place.  Get a good desoldering tool.  I got this one and it makes the job EASY!!

American HAKKO FR301-03/P ESD Safe Portable Desoldering Tool with Precise Temperature Control °F /°C

https://www.amazon.com/American-HAKKO-Products-FR301-03-Desoldering/dp/B07BFVFMS9/ref=sr_1_5?crid=W0ZX7ZDCJBKB&keywords=desoldering+gun&qid=1661739796&sprefix=desolder%2Caps%2C115&sr=8-5&ufe=app_do%3Aamzn1.fos.ac2169a1-b668-44b9-8bd0-5ec63b24bcb5


Alrighty, I'll have to invest in that then for future projects. I'm in the middle of a career shift and spending that kind of cash isn't in the budget lol but fortunately I have a pretty good/ great soldering iron I can just do the old fashioned way on. Thank you!

So I swapped out the SHARPs & no luck. The monitor powers on, but stays on for even less time & then shuts back down. 😔