Smasung SyncMaster 913N Monitor wouldnot display images

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

I just replaced the 1000uF 16v cap which is located on the top right and its still got the same issue. I'll replace the big 100uF 450v cap and if it still doesn't work then I really don't know what else it is apart from the other IC I've not checked.

Daniel

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

gonzo0815,

I see. I am about to replace another capacitor that I didn't manage to last night due to not having a replacement and then I just need to replace the bigger one. If it still doesn't work then I will leave this because I may aswell just buy a screen for £80. Also I am not amazing with a soldering iron and replacing the bigger IC on the underside of that board doesn't look like a fun thing todo to me.

I had a look on that ebay link and searched or NT68F63L and it displayed a few chips which would NOT fit as a replacement to the ones located on the underside which I mentioned above. I did try and source a supplier for the entire psu but haven't found anyone yet.

Daniel

That part is the controller on the logic board. You have demonstrated that the problem is on the power supply.

PlainBill

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

My mistake, I just looked at the other pcb and reliased.

[Bobdee]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

I just replaced the 1000uF 16v cap which is located on the top right and its still got the same issue. I'll replace the big 100uF 450v cap and if it still doesn't work then I really don't know what else it is apart from the other IC I've not checked.

Daniel

Hello Daniel
Go with Plainbills advice, Gonzos post does not apply to you
Bathuu and Me have monitors that the green light comes on, searches for signal then goes off after about 8 second and then keeps on repeating itself
You said yours has rapid on/off, Bill Knows your problem,as for the big cap they rarely fail as Bill will advise

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

I just replaced the 1000uF 16v cap which is located on the top right and its still got the same issue. I'll replace the big 100uF 450v cap and if it still doesn't work then I really don't know what else it is apart from the other IC I've not checked.

Daniel

I'm afraid I've neglected some of the basic rules of troubleshooting. There are things going on with this monitor that are new to me. Let's start with the basics and move forward from there.

I've uploaded an edited picture of a power supply / inverter board which should be identical to yours. I have marked a screw with a black circle and a connector with a red box. Hook the power supply / inverter board up as it normally would be in the monitor. Install the four screws in the corners, and hook up all cables. Set your DMM to the 20 volt DC range. Make certain the button I have circled in orange is set to the DC position.

At this time plug the power cord into an outlet. BE VERY CAREFUL NOT TO YOUR HANDS TO TOUCH ANY PART OF THE MONITOR. Sorry for shouting, but lethal voltage may be present.

Place the black meter lead on the screw I circled, then measure the voltage on each of the 9 pins of the connector. Some of the pins will measure 0 volts, others should show about +5 volts. By convention, we say that the red wire in the cable goes to pin 1. List the voltages by pin, and note any that appear to be fluctuating.

Next, change your meter to the 1000 volt scale and measure the voltage on the leads of the very large cap - I've circled them in green. Note that voltage, and if it appears to be fluctuating. Unplug the monitor, have a brief break.

I know the UK uses different voltages than we do here in the US (AKA your former colonies), but I don't recall what they are. The voltage across the leads of the large cap should be roughly 1.4 times your mains voltage. Here in America we use a nominal line voltage of 120 VAC; I would expect to see 165 VDC across the leads of the large cap. I would suspect a problem with the live side of the power supply only if the voltage was below 140 VDC.

After you have had your rest, I would like a good picture of the back of the power supply / inverter board.

PlainBill

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

Thanks for your time. I have done what has been asked and the results are below:

red is pin 1 and working from the red pin right to pin 9 left.

1 = 10 to 12 volts
2 = 10 to 12 volts
3 = 0
4 = 0
5 = 0
6 = 0.80 to 1.70
7 = 0.80 to 1.90
8 = 0.96 to 1.70
9 = 0.09 to 1.60

large cap 216v stable - I tested it three times and it came back with 216v, Our mains voltage is 230vac.

Daniel

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

Thanks for your time. I have done what has been asked and the results are below:

red is pin 1 and working from the red pin right to pin 9 left.

1 = 10 to 12 volts
2 = 10 to 12 volts
3 = 0
4 = 0
5 = 0
6 = 0.80 to 1.70
7 = 0.80 to 1.90
8 = 0.96 to 1.70
9 = 0.09 to 1.60

large cap 216v stable - I tested it three times and it came back with 216v, Our mains voltage is 230vac.

Daniel

Well done. Unfortunately, I'm confused. The voltage across the large cap should be about 320 volts. If the cap were bad I would expect to see some fluctuation there. The voltages on pins 6-9 could indicate there is an excessive load on the 5 volt supply.

I hate to ask this, but would you please do the same measurements on a working monitor.

EDIT: I'm rethinking this. Replace the large cap. It can't be an excessive load on the Power supply / inverter board; one from a good monitor works fine. The voltage on the large cap is VERY low. There are only a few explanations for that, the cap, the thermistor, and possibly the bridge rectifier.

Reedit: Double check the orientation of all the caps you replaced. I've been burned by that mistake myself.

PlainBill

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

I will do the same checks on a working monitor. I replaced all the caps the correct way. I have a replacement cap coming for that 100uF 450v.

Daniel

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

I have finished testing the working monitors PSU. Th results are below.


1= pin 1 - red // 9= pin 9 black

1 = 12.99 stable
2 = 12.99 stable
3 = 0.01
4 = 0.01
5 = 0.01
6 = 5.02 stable
7 = 5.02 stable
8 = 0.01
9 = 4.19 stable

large cap

test 1 = 312 stable
test 2 = 312 stable
test 3 = 312 stable

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

I have finished testing the working monitors PSU. Th results are below.


1= pin 1 - red // 9= pin 9 black

1 = 12.99 stable
2 = 12.99 stable
3 = 0.01
4 = 0.01
5 = 0.01
6 = 5.02 stable
7 = 5.02 stable
8 = 0.01
9 = 4.19 stable

large cap

test 1 = 312 stable
test 2 = 312 stable
test 3 = 312 stable

Those numbers are what I would expect. At a guess, 1 and 2 are for the bucking supplies on the video (logic) board. 3,4,5 are ground. 6 and 7 are the 5V supply to the video (logic) board. 8 is the backlight control, and 9 is brightness.

Try as I might, I can't come up with any logical explanation (other than a bad cap) for the other voltage being low. I doubt that a bad bridge would do it; a bad thermistor would be glowing red from the power it was dissipating.

I guess it makes sense. There is some debate on replacing the big cap. I usually don't bother. One guy said he had repaired over a hundred monitors and had only one where the big cap had failed. Between those I've fixed personally and those I gave advice to here, the total comes close to 100. Too bad yours was the one.

PlainBill

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

I see. I've got a replacement big cap coming so I'll replace it and see if that works. Knowing my luck it probably is the big one and simply replacing it will fix it. However I cannot see any bulging on the cap or anywhere else I have replaced caps.

Either way if it works or not this has been a great learning experience. I have seen forum post somewhere else about some guy using a pc psu in order to power his monitor although I'd need to look into this. There are also four connectors on this board two at the top and at the bottom which I believe are for the backlight and they would need powering.

Daniel

[EGuevarae]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

I guess it makes sense. There is some debate on replacing the big cap. I usually don't bother. One guy said he had repaired over a hundred monitors and had only one where the big cap had failed. Between those I've fixed personally and those I gave advice to here, the total comes close to 100. Too bad yours was the one.

PlainBill

Around 80, Never had to replace the big boy.
Eduardo

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

I see. I've got a replacement big cap coming so I'll replace it and see if that works. Knowing my luck it probably is the big one and simply replacing it will fix it. However I cannot see any bulging on the cap or anywhere else I have replaced caps.

Either way if it works or not this has been a great learning experience. I have seen forum post somewhere else about some guy using a pc psu in order to power his monitor although I'd need to look into this. There are also four connectors on this board two at the top and at the bottom which I believe are for the backlight and they would need powering.

Daniel

I'm not a fan of that approach. Certainly it is possible (in some cases). A lot depends on what you plan on doing with the monitor. An obvious consequence is the monitor and pc are tied together.

PlainBill

[EGuevarae]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

I'm not a fan of that approach. Certainly it is possible (in some cases). A lot depends on what you plan on doing with the monitor. An obvious consequence is the monitor and pc are tied together.

PlainBill

I've done it, but you need to be sure your PSU could handle both your PC and the LCD. I did it just as an experiment, and I am not using a monitor that way currently. I used it like that for like a month.

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

Guys,

It would be an old psu I have lying around screwed onto the back by the mounting screws and just being used to power the monitor. I'd have to get the correct voltage though for whats required. I'll have a play.

This is where I got the idea:

http://computerguru365.blogspot.com/...l-monitor.html

Personally I'd rather fix what I have because it looks better and it would be good because I've got three other types of this monitor which could have the same issue. The psu on the back is the last resort however if it works it'll save a 19inch from being scrapped.

Dan

[gonzo0815]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

Those NT68F63L are already programed, but you can program it by your own with the EasyWriter software from Novateck and a simple LPT > VGA adapter.
So you should be able to save your original firmware (careful, obey the correct checksum) and program it to the new chip.
ATM i do not know which chip is the right one, if no of them offered match your four digit code. But for the 913N i think they do offer one. or simply ask the seller.
I have replaced the video board completely in my 913N and it wasn`t the original one. The monitor does now have another DDC name, but that doesn`t hurt.

Removing the PLCC chip could be done by cutting the pins with a dremel or a precise cutting tool, then desoldering the pins one by one. This should be easy if done carefully.
Hot air gun is another possibility, but some care have to be taken to avoid desoldering some SMD devices, as the whole pcb would become hot.

As some hesitate to believe it, if your Syncmaster has the "out of range" problem or it does nothing when connected to a VGA card, no capacitor or psu swap will fix it.
And probably no other hack will do it in the long run. You have to replace the video chip, in this case the NT68F63L.

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

Hi,

On the video board it has two chips one has samsung magic colour written on it and the other has a white label on it which reads

MJ19E_9.IE
2005.10.11
47EF

That top code may or may not be any use anyone. I appreciate your comments regarding the out of range however in my case the monitors power led (green) flickers very rapidly. On reflection of this and what's been discussed on here I do believe that is caused by a power problem (power fluctuationing or not enough power). The replacement large cap or "Big Boy" as its been named should be here today if royal mail get a move on, people in the UK will know what I'm talking about.

Daniel

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

Hi Guys,

Good news I replaced the 100uF 450v cap and the monitor came back to life. The cap wasn't exactly the same size but it works. I had to make a holes in the metal chassis but that's down to me not measuring all the replacement caps before buying. I've taken a few pictures for you guys to see the handy work which isn't amazing in this attempt. The next monitor I fix will be done much much better than this but you can't beat experience I suppose. The monitor is running great/normal but I will have to test to however for now its good. I did replace 12 caps in total so I shouldn't have any future issues.

I'm definently going to re-think any future monitor/tv purchases and recommendations because its kinda annoying samsung are using this crappy components ie crapxon.

I'd like to thank all of you guys especially PlainBill your help has been great, I plan to stick around and help others out. I am sure there will be someone else who has had the same problem and needs a fix which is proven and works, well certainly in my case.

Thanks guys.

Daniel

[PlainBill]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

Hi Guys,

Good news I replaced the 100uF 450v cap and the monitor came back to life. The cap wasn't exactly the same size but it works. I had to make a holes in the metal chassis but that's down to me not measuring all the replacement caps before buying. I've taken a few pictures for you guys to see the handy work which isn't amazing in this attempt. The next monitor I fix will be done much much better than this but you can't beat experience I suppose. The monitor is running great/normal but I will have to test to however for now its good. I did replace 12 caps in total so I shouldn't have any future issues.

I'm definently going to re-think any future monitor/tv purchases and recommendations because its kinda annoying samsung are using this crappy components ie crapxon.

I'd like to thank all of you guys especially PlainBill your help has been great, I plan to stick around and help others out. I am sure there will be someone else who has had the same problem and needs a fix which is proven and works, well certainly in my case.

Thanks guys.

Daniel

I'm glad to see it's working. Perhaps the first step of my instructions should be 'Check the voltage at the main filter capacitor.'

PlainBill

[dan86]

Re: Smasung SyncMaster 913N Monitor wouldnot display images

PlainBill,

Yeah I'd definitely check the "Big Boy" first.

Daniel