Samsung Syncmaster 1100DF CRT monitor ("ON" issues)

[13hm13]

I am the orig. owner of this monitor, purch'd new in Feb .2004. It has pretty low hours as it was only in active (but non-continuous) use about 1.5 years. The monitor also has an automatic "sleep" mode that will partially power down the monitor after about 15 min. of non-use.

The problem is this: the high voltage will not power on. When main pwr button (front) is pressed, a non-blinking green PWR LED will come on. But the high-voltage section does not seem to power up (or is not getting the signal to power up). Even if no video input is connected, the display should still display (e.g., message like NO VIDEO CONNECTED).

I have checked the supply pins to the logic chips (5V) and they seem fine. (The main pwr LED turns on and off as normal).
No bulging caps or signs of scoring, heat damage or other "abuse" on a visual inspection.

I have very little experience with servicing CRT monitors, so any clues as to what to inspect next is appreciated.
Thx!

Attached is the full Service Manual (PDF)

[PKTKS]

Actually this unit puts together:

- a SYNCed PWM H driver stage
- with a front end PFC controller MC33260

this is not trivial to check as you need to safe pass check
all the flyback issues first.

checking the flyback coils and the drivers.

Certainly you will need to check some wave forms
and they are all pretty much HIGHV PULSEs

This SMPS is not something to take light
it must sync with the incoming signal as well

Paul

[13hm13]

Actually this unit puts together:
[...]

this is not trivial to check

I think troubleshooting this unit in the std. way is more time than I'm willing to spend.

I'm looking more for anecdotal accounts like  ...

"Yeah, we saw that often in the shop and we fixed it by [solution]"

or:

"Try checking transistor X -- is it blown?"

[PKTKS]

I'm looking more for anecdotal accounts like  ...
"Yeah, we saw that often in the shop and we fixed it by [solution]"
or:
"Try checking transistor X -- is it blown?"

Nahh  this is monitor of high quality results.
Requires specialized technicians with some necessary skills

That pudim thing that "RECAP" or just 'REPLACE THIS...THAT .. tap.. bend.."
this is for the 5 minute corner shop

That kind of device requires a bit more - also proper equipment
and necessary caution handling it

Lucky shots are on the very bottom of the list
Paul

[13hm13]

Finally pulled the main board completely out. Have been thru most of the electro caps with ESR meter. And they test like new.
Tested many (but not all) diodes. They are okay.
Again this monitor , purch'd new March 2004, was in moderate (but not heavy), daily use for about 15 mos. After that, occasional use for about 3 years (10 hrs/ month).
I'm guessing a chip, IC (voltage reg, transistors, etc), etc. is the culprit.
Visual inspection of the PCB (and mounted components) reveals no heat damage or other visible signs of "wear", like cracked solder joints ,etc .

[13hm13]

It's OBVIOUS that EEVBlog Forum is NOT the place for CRT problem-solving.
Anyone know of a forum or message board that is?

[Rasz]

Any place with time machine. Its like asking about Steam locomotive on a car mechanic forum - only bitter retired oldtimers collecting locomotives will chime in.

Even at CRT prime there were no corner TV repair shops that would take this monitor for service. It was only specialized manufacturer RMA centers with own diagrams and repair manuals.

https://www.edaboard.com/threads/req-samsung-syncmaster-1100df-service-manual.69348/post-306149 has troubleshooting and diagrams with all the service voltages

[PKTKS]

I's OBVIOUS that EEVBlog Forum is NOT the place for CRT problem-solving.
Anyone know of a forum or message board that is?

This is pretty old stuff..

I am having issues finding parts for modern... this one is really needle

In case you need parts.. i have a half dozen scrap boards of vintage syncmasters

Drop a note with the part...

Paul

[13hm13]

Any place with time machine. Its like asking about Steam locomotive on a car mechanic forum - only bitter retired oldtimers collecting locomotives will chime in.

Even at CRT prime there were no corner TV repair shops that would take this monitor for service. It was only specialized manufacturer RMA centers with own diagrams and repair manuals.

https://www.edaboard.com/threads/req-samsung-syncmaster-1100df-service-manual.69348/post-306149 has troubleshooting and diagrams with all the service voltages

I already have the SM. It is an attachment in the orig Top Post (see above).

[13hm13]

I's OBVIOUS that EEVBlog Forum is NOT the place for CRT problem-solving.
Anyone know of a forum or message board that is?

This is pretty old stuff..

I am having issues finding parts for modern... this one is really needle

In case you need parts.. i have a half dozen scrap boards of vintage syncmasters

Drop a note with the part...

Paul

Hi!
Thx for offering to supply parts for my SyncMaster DF1100 CRT monitor repair!

I have gone thru most but not every possible problematic source.

I think I need a new NT86F63 which is IC201 in the PDF manual attached in the orig top post. See page 68, page 35.

From Parts List in the PDF: IC-MICROCONTROLLER --  T86F63, 8BIT, SDIP, 42P,600MIL,12MHZ,ST,CMOS,PLASTIC,5V,-,0TO+70C,1152B,4KB,-,-,8B SA



I can find no source of this chip on the internet. It has a white sticker with black print.
If you don't have it, maybe you can help with a substitute.

Note again:
 When I turn the unit on, I get the solid LED (at the Power button). If I plug in a source (RGB, etc), that LED will dimly blink.
Also note: I get no degaussing thump at when power up.
The monitor has low hours and was always plugged into filtered UPS power. All the electro caps and all the diodes checked are OKAY. Also checked the Horiz. Out Transistor and some (but not all) other regs (okay). Have not tested the To-92 transistors.

[Rasz]

its a PROM microcontroller, even if you could exact chip you wouldnt have correct firmware for it
what makes you think its dead? have you probed its IO, clock, supply ?

[13hm13]

its a PROM microcontroller, even if you could exact chip you wouldnt have correct firmware for it
what makes you think its dead? have you probed its IO, clock, supply ?

The SM has a troubleshooting flowchart. Based on symptoms (No Video; HV not engaging; No start-up degauss thump; Front Power Led ON or Led rapidly blinks if RGB connected) ... suggests IC201. Please look at the SM in top post.
5+ volt rails are okay. when i tested. Nothing in SM suggests firmware updating. That said, there is a USB port on the back (and that port does interface with IC201 .... hmmmmmmmmmmm...).

[inse]

I wonder how the uC can still blink the LED when it needs to be replaced?

[13hm13]

I wonder how the uC can still blink the LED when it needs to be replaced?

The "LED" is one pin out from IC201. But this same IC (IC201) also controls HV section as well as DEGAUSS -- both of which fail at power on. It may be that ONLY a part of the IC that has gone bad. Or it may be something else entirely ( solder joint, another IC, TO-92 trans., etc).
Again, folks, PLEASE look at the PDF Service Manual in the FIRST POST (esp. p68, as well as the TROUBLESHOOTING flowcharts).

[Rasz]

I wonder how the uC can still blink the LED when it needs to be replaced?

reset loop?

its a PROM microcontroller, even if you could exact chip you wouldnt have correct firmware for it
what makes you think its dead? have you probed its IO, clock, supply ?

The SM has a troubleshooting flowchart. Based on symptoms (No Video; HV not engaging; No start-up degauss thump; Front Power Led ON or Led rapidly blinks if RGB connected) ... suggests IC201. Please look at the SM in top post.
5+ volt rails are okay. when i tested. Nothing in SM suggests firmware updating.

I was wrong! Its flash based after all http://www.datasheet-pdf.com/PDF/NT68F632-Datasheet-Novatek-945645 Samsung diagrams have a typo
$10 for 5 chips https://www.ebay.com/itm/233540132031?hash=item3660139cbf
I2C programmed, apparently also possible to read back firmware (no read protection?) using for example RT809F. I didnt find any free programming software/hardware combo supporting it yet, but its possible you could program this using arduino/rpi if someone wrote a tool, high chance seeing this is a common failure
I found this https://www.badcaps.net/forum/showthread.php?p=909333 and Syncmaster 710N immediatelly rang a bell - that Nuvoton chip was dying in a very peculiar way where heating it with a hotair would bring it back to life! maybe internal flash is on separate die and bond wires get lose with time or something weird like that.

That said, there is a USB port on the back (and that port does interface with IC201 .... hmmmmmmmmmmm...).

connected to ordinary IO pins, most likely running software low speed USB device stack

Here is an idea - EDID DDC eeprom is behind the microcontroller, access will only work if micro is running. You can test if its alive by connecting monitor to VGA card and seeing if its detected by windows with proper name and all EDID data (either in Nvidia control panel or somethin like CRU.exe will list monitors).

If this test fails you can try
- https://www.badcaps.net/forum/showthread.php?t=25242&highlight=NT68F63 gives "try the (47 or 50 Ohm) resistor hack at pin 5-6". Iv seen this secret cryptic solution in few places.
-blasting it with heat as a last resort, like couple seconds at 300C.

If this test passes its most likely not the microcontroller, but might be worth trying the above anyway? or get a replacement just in case. Of course first you would have to somegow find another 1100df to read back original firmware.

[13hm13]

I wonder how the uC can still blink the LED when it needs to be replaced?

reset loop?

its a PROM microcontroller, even if you could exact chip you wouldnt have correct firmware for it
what makes you think its dead? have you probed its IO, clock, supply ?

The SM has a troubleshooting flowchart. Based on symptoms (No Video; HV not engaging; No start-up degauss thump; Front Power Led ON or Led rapidly blinks if RGB connected) ... suggests IC201. Please look at the SM in top post.
5+ volt rails are okay. when i tested. Nothing in SM suggests firmware updating.

I was wrong! Its flash based after all http://www.datasheet-pdf.com/PDF/NT68F632-Datasheet-Novatek-945645 Samsung diagrams have a typo
$10 for 5 chips https://www.ebay.com/itm/233540132031?hash=item3660139cbf
I2C programmed, apparently also possible to read back firmware (no read protection?) using for example RT809F. I didnt find any free programming software/hardware combo supporting it yet, but its possible you could program this using arduino/rpi if someone wrote a tool, high chance seeing this is a common failure
I found this https://www.badcaps.net/forum/showthread.php?p=909333 and Syncmaster 710N immediatelly rang a bell - that Nuvoton chip was dying in a very peculiar way where heating it with a hotair would bring it back to life! maybe internal flash is on separate die and bond wires get lose with time or something weird like that.

That said, there is a USB port on the back (and that port does interface with IC201 .... hmmmmmmmmmmm...).

connected to ordinary IO pins, most likely running software low speed USB device stack

Here is an idea - EDID DDC eeprom is behind the microcontroller, access will only work if micro is running. You can test if its alive by connecting monitor to VGA card and seeing if its detected by windows with proper name and all EDID data (either in Nvidia control panel or somethin like CRU.exe will list monitors).

If this test fails you can try
- https://www.badcaps.net/forum/showthread.php?t=25242&highlight=NT68F63 gives "try the (47 or 50 Ohm) resistor hack at pin 5-6". Iv seen this secret cryptic solution in few places.
-blasting it with heat as a last resort, like couple seconds at 300C.

If this test passes its most likely not the microcontroller, but might be worth trying the above anyway? or get a replacement just in case. Of course first you would have to somegow find another 1100df to read back original firmware.

Your feedback is good!
I, myself, thought of connecting my laptop via USB input of the 1100DF to see what the laptop can detect. I know that 1100DF is supplying clean  5 v logic power to its ICs.

About the  http://www.datasheet-pdf.com/PDF/NT68F632-Datasheet-Novatek-945645 link you provided.
This is NOT meant for Samsung CRT monitors .... it is for LCD.  MAYBE, Samsung buys generic 42-pin 8 Bit Microcontroller and flashes them in-house. And then EXPECTS all techs to order pre-flashed ICs from Samsung??
Not sure why you feel so strongly about IC210 having the wrong firmware? It is an old-school ASIC that is meant as "plug-n-play" device of a sort. Many of the monitor adjustments are via the Service Mode (like color temp, etc).

Keep in mind a few things:

When one normally powers up the 1100DF monitor -- even with absolutely no inputs connected -- one hears the thud of the de-gaussing coil and and crackling static buildup on the CRT--all normal of CRT units. And if no input is connected, the CRT screen will have a scrolling OSD message stating "Check Input Connection". And, also, one can adjust color and tint via the front-panel buttons (that have OSD display regardless of any input device being connected).

The 72-page Service Manual states NOTHING about flashing or updating firmware on chips if they are replaced. Again, MAYBE, Samsung buys generic 42-pin 8 Bit Microcontroller and flashes them in-house.And then EXPECTS all techs to order pre-flashed ICs from Samsung??

 This 1100DF monitor is from 2003, built Feb 2004. It's old but with low hours.

It's hard to work on (probe) the main board of the 1100DF because of the ridiculous position it is in. In order to gain clearance to probe, one has to disconnect much of it from the other sections (CRT, BNC/rear-ports board, front panel board)

[Rasz]

I, myself, thought of connecting my laptop via USB input of the 1100DF to see what the laptop can detect.

but also test what windows says with VGA connected

About the  http://www.datasheet-pdf.com/PDF/NT68F632-Datasheet-Novatek-945645 link you provided.
This is NOT meant for Samsung CRT monitors .... it is for LCD.

this is a datasheed for later more advanced micro from same family, its one letter off. NT68F632 vs NT68F63. It has more dedicated hardware blocks (second i2c master/slave, dedicated serial etc).
Here is LCD monitor using your exact chip: https://www.qdatasheet.com/datasheet-download/883752/1/Novatek/NT68F63
curiously it calls pin 6 V33 and calls this power rail "REF 3.3V" - this gives some credence to "try the (47 or 50 Ohm) resistor hack at pin 5-6" for old tired chips with degraded internal 3.3V reg and reviving them by pulling it high to 5V.

Not sure why you feel so strongly about IC210 having the wrong firmware? It is an old-school ASIC that is meant as "plug-n-play" device of a sort.

its not asic/plug and play. In old monitors/TVs it was common to find OTP microcontrollers (one time programmable) but this one is flash based.
If yours is bad and cant be revived by pin 5-6 hack or baking in 300C then you will need firmware from somewhere to program replacement.

The 72-page Service Manual states NOTHING about flashing or updating firmware on chips if they are replaced. Again, MAYBE, Samsung buys generic 42-pin 8 Bit Microcontroller and flashes them in-house.And then EXPECTS all techs to order pre-flashed ICs from Samsung??

yes, RMA centers are expected to work fast, back in the day they most likely had access to preprogrammed chips

It's hard to work on (probe) the main board of the 1100DF because of the ridiculous position it is in. In order to gain clearance to probe, one has to disconnect much of it from the other sections (CRT, BNC/rear-ports board, front panel board)

In that case I solder few probe wires sticking out of the case (careful not to short dangling ends)

[13hm13]

Thx for the feedback!


I suspect the firmware got corrupted somehow. The SAME chip may be good if it could be re-flashed. But I don't know how to do that.

I'll do some more investigating this weekend or early next week as time permits. This monitor is just a hobby project. I'm not in the service industry, so there is no customer waiting.

About why pursue CRT monitors at all in 2022. Just search Reddit, the gaming forums or YouTube for "CRT monitor". The gaming community actively seeks them out -- even old TVs from the 80s, modded with RGB input -- because of their fast response time (refresh rate). An important part of the gaming experience, I assume!
Also, for movies and video, the smooth look and "feel" of better CRT monitors and tv's (like what professional Sony PVMs can do; or this Samsung monitor 1100DF, when it's working!) is unique. So, movie studios also actively seek them out, too.
And they can fetch some $$ ... Some of the prices of better CRT "vintage" monitors on eBay or Craig's List are quite spectacular.

[13hm13]

And they can fetch some $$ ... Some of the prices of better CRT "vintage" monitors on eBay or Craig's List are quite spectacular.

This new video   presentation on the History of the cathode ray tube was presented at the Museum of Fine Arts, Houston, TX. The outlandish prices of CRT monitors are at the end of the seminar.
https://youtu.be/_N8jnVl-Yts

[13hm13]

I was wrong! Its flash based after all http://www.datasheet-pdf.com/PDF/NT68F632-Datasheet-Novatek-945645 Samsung diagrams have a typo

Yes! The Serv. Manual has it wrong (or: sophistry---may be deliberately lying to obfuscate !!) Anyway, I removed the sticker and it is indeed the Novatek IC:

[Rasz]

I suspect the firmware got corrupted somehow. The SAME chip may be good if it could be re-flashed. But I don't know how to do that.

main failure mode for this chip is dying, not corrupted firmware. There are tons of posts on the net (mostly on russian repair forums) about reanimating monitors by baking those chips. I remember reading about this trick 10-15 years ago. Pin 5-6 60ohm pullup one is new for me, but makes some sense and is worth trying after measuring voltage on pin 6.

[13hm13]

I suspect the firmware got corrupted somehow. The SAME chip may be good if it could be re-flashed. But I don't know how to do that.

main failure mode for this chip is dying, not corrupted firmware. There are tons of posts on the net (mostly on russian repair forums) about reanimating monitors by baking those chips. I remember reading about this trick 10-15 years ago. Pin 5-6 60ohm pullup one is new for me, but makes some sense and is worth trying after measuring voltage on pin 6.

Well, first I'm going to re-solder (re-flow) all 42-pins on that chip. That should heat it up.
Another trick is to clean up the power to Vcc by bypassing with a high-quality film cap (Vcc to GND).
Not clear about the "Pin 5-6 60ohm pullup". Are you saying solder a 60 ohm R from Pin 5 to Pin 6?

On a side note, what could cause that IC to go bad? As noted, all the caps and components around it are in "like new" cond given the low hours and gentle use of the monitor. Clean AC was fed to this monitor -- as are all my devices -- via some "audiophile" line conditioners I've accumulated.
Also, older tv's did not use uC's like the Novatek -- but still managed to do the work w/o chips. So I wonder how much of the Novatek's functions could not be bypassed? I mean if it's ONLY supplying low-voltage trigger signals to HV, degauss, etc ... then, those might be manually triggered. Old tv sets used to simply "ON" everything immediately upon pressing power --- no delay microprocessor was needed.

[shakalnokturn]

Also consider that failure to access or corrupted data in 24Cxx memory can sometimes have unpredictable results.
This is a case where I'd probe serial bus, try finding a good memory dump or at worse try swapping for a blank memory and check for changes in behaviour.

[Rasz]

without running NT68F63 monitor wont do anything as its managing the TDA9112 LOW-COST I2C CONTROLLED DEFLECTION PROCESSOR FOR MULTISYNC MONITOR
http://pdf.datasheetcatalog.com/datasheet/SGSThomsonMicroelectronics/mXyuxuw.pdf
without being programmed live according to incoming signal that chip wont produce any picture

[andy2000]

Absolutely, the part would have normally been purchased from Samsung preprogrammed.  It sounds like this particular part has an abnormally high failure rate.  Normally, parts like micro controllers are very reliable.  I've only seen a few fail, usually in TVs that were hit my lightning. 

The part number to look for is the one in the parts list (0903-001263), not the generic model number for the micro controller.  Custom parts like this tended to become unavailable not long after the product was discontinued, so finding one in 2022 will be difficult.  At least Samsung's system still recognizes the part number.  You might be able to find a surplus one somewhere.  Keep a search saved on ebay since people sometimes list batches of random parts.

https://samsungpartsusa.com/products/0903-001263