Samsung SyncMaster 226BW

[RCinFLA]

Re: Samsung SyncMaster 226BW

Samsung seems to have a reputation of putting filter caps with a voltage rating too close to operating voltage. I had a Samsung LCD TV that went out. The warranty service guy had a bag of 2200uF 50 vdc caps in his tool box to replace the stock 2200 uF 25 vdc cap in the power supply board.

The caps in the monitor p.s. board are the output filters of the switching power supply. I replaced mine with 35 volt parts to give them more margin.

The large 150 uF 450 volt cap is the main input filter that filters the rectified AC line input. The voltage rating is high to account for 240 vac line input (produces about 340 vdc). For U.S. 120 vac operation it has plenty of margin running at 170 vdc. If this cap is bad there would be nothing powering up (other then blue light which runs from a parallel low power supply).

[meepins]

Re: Samsung SyncMaster 226BW

My 226bw C began flickering about a week ago. Im currently on a very tight budget and cant afford the capacitors plus shipping. I'll be able to purchase them when i get my next paycheck, but I was wondering if anyone has an idea of how long it will take for the monitor to not eventually warm up and stop flickering. I realize theres no exact time limit, just wondering if it would be best to leave the monitor always on or not because I do not have a temporary replacement available until im able to get the parts and fix the problem. i should mention that i have been completely unplugging the monitor when i go to bed and have turned off sleep mode and left it running throughout the day. Any advice would be appreciated

[Rtech]

Re: Samsung SyncMaster 226BW

Looks like you are between a rock and a hard place.If you turn it off, its anyones guess how long it would take to run properly,however if you leave it on, the heat generated(one of the main causes of cap failure),will continue to degregate the caps,until the thing stops working completely.Good luck.

[danchapman84]

Re: Samsung SyncMaster 226BW

My 226BW has started to flicker and I am going to attempt to replace the caps. I have a few questions.

1. I do not want to electrocute myself. How do I make sure the power board is no longer holding a charge?

2. Where can I get a good soldering iron? What is best to remove the old solder?

Thank you for your help

[jetadm123]

Re: Samsung SyncMaster 226BW

My 226BW has started to flicker and I am going to attempt to replace the caps. I have a few questions.

1. I do not want to electrocute myself. How do I make sure the power board is no longer holding a charge?


2. Where can I get a good soldering iron? What is best to remove the old solder?


Thank you for your help

Unplug monitor and wait a few minutes. With your meter set to DC volts, measure the voltage across the large 450V cap. It should read close to zero volts.

If you're going to perform a minimal amount of soldering, go ahead and pick up a 40W iron and some solder wick (desoldering braid) from Radio Shack. If there are no stores near you, then purchase through eBay.

[danchapman84]

Re: Samsung SyncMaster 226BW

jetadm123 thank you for the quick reply. If I do not have a meter and unplug the monitor for like 10 minutes do you think that will be long enough?

[jetadm123]

Re: Samsung SyncMaster 226BW

With high voltage, you should NEVER assume anything. A 100W light bulb in a socket and some alligator test leads connected across the large cap will drain it immediately. Some members will suggest placing a screw driver across the positive and negative leads of the cap to drain it, but this sudden discharge can cause a voltage spike and damage other components.

[mahkitah]

Re: Samsung SyncMaster 226BW

Thanks everybody here.
I was able to repair my 226BW after reading this thread.

My display stayed black after starting up and came to life with some flickering after some time.
This took increasingly longer, till in the end it just stayed black.

I replaced 5 820 uF 25V and 1 330 uF 25V cap with their equivalent from Rubycon. (ZLH and ZLG series)
I had the local electronics shop order them from Farnell. (took 1 day)

Now everything is working fine again.

[TechEffect]

Re: Samsung SyncMaster 226BW

I spent an hour earlier today at work repairing one of these before I saw this thread!
I had the lovely two second display, and after replacing all the caps EXCEPT the very large one, it works perfectly.
Thanks guys!
I'm just glad work has these caps in stock and I don't have to go out and find them like most!

[pedro]

Re: Samsung SyncMaster 226BW

I spent an hour earlier today at work repairing one of these before I saw this thread!
I had the lovely two second display, and after replacing all the caps EXCEPT the very large one, it works perfectly.
Thanks guys!
I'm just glad work has these caps in stock and I don't have to go out and find them like most!

I only hope - for your sake - that those work stock caps are reputable low-ESR 105C caps and not GP ones.

[Bjerols]

Re: Samsung SyncMaster 226BW

hey everyone who helped out in this thread and who own this website, I am posting this message from my now refurbished Samsung 226BW! Cost me @ $5 shipped and an hour of my time but it was well worth it... thanks for all the help!!

[reflex]

Re: Samsung SyncMaster 226BW

Hi all

Thanks very much for the advice given in this thread - great that you guys are willing to share your knowledge like this.

Despite never having soldered a thing in my life, I ordered some caps and replaced my dodgy ones, but my problem is still exactly the same. I've never had flicker, but I had been having a high pitch whining noise from the monitor for a while, then after returning from a break I turned it on and the screen was just blank. If I shine a light on it, the image is there, just very dim.

I have noticed on ebay there are replacement power boards. If I was to buy one of these, what are the chances it would fix my problem? Or is my problem likely to be something to do with the screen itself or something on teh graphics board? I don't want to spend another £30 having already spent £20 on a gun and caps for it not to work, when this £50 could have gone towards a monitor.

Advice would be greatly appreciated.

[alexanna]

Re: Samsung SyncMaster 226BW

If you do not notice a brief flash of the back lights when you power the monitor on,you should check the fuse in the inverter area for being open.

[reflex]

Re: Samsung SyncMaster 226BW

If you do not notice a brief flash of the back lights when you power the monitor on,you should check the fuse in the inverter area for being open.

Sorry for being stupid (I really don't know anything about eletronics), but where do i find the fuse, and look to see if it's open? I can't see a conventional fuse on the board. I searched the thread for a picture of where the fuse/s are but my board layout is different to the picture.

[reflex]

Re: Samsung SyncMaster 226BW

Sorry ignore that, I have managed to find them. They look ok, but then I don't know what I'm really looking for.

[alexanna]

Re: Samsung SyncMaster 226BW

How about posting some photos of the top an bottom of the power supply/inverter.
An in focus straight down using managed attachments

[PlainBill]

Re: Samsung SyncMaster 226BW

Sorry for being stupid (I really don't know anything about eletronics), but where do i find the fuse, and look to see if it's open? I can't see a conventional fuse on the board. I searched the thread for a picture of where the fuse/s are but my board layout is different to the picture.

It is very common for manufacturers to use several variations of the power supply in any given model of monitor. It is not unheard of for a manufacturer to have major revisions in the signal card also. That is why we ask for pictures of the power supply.

As far as a replacement power supply, if it is identical to the one in your monitor, it is very likely it will solve the problem. There is a small, but significant chance the problem is in the CCFLs or CCFL wiring.

PlainBill

[reflex]

Re: Samsung SyncMaster 226BW

Plainbill: The boards I've found on ebay look quite different to mine, they're much more sparser in terms of the number of components for some reason. I guess would be a real challenge finding my exact one.

I have attached pictures. You can see how shoddy my attempt at soldering is, but the solder touches both the caps and the board. I'm guessing I may have screwed it though, and I might have to resign myself to binning the monitor

[PlainBill]

Re: Samsung SyncMaster 226BW

Plainbill: The boards I've found on ebay look quite different to mine, they're much more sparser in terms of the number of components for some reason. I guess would be a real challenge finding my exact one.

I have attached pictures. You can see how shoddy my attempt at soldering is, but the solder touches both the caps and the board. I'm guessing I may have screwed it though, and I might have to resign myself to binning the monitor

F301 is the fuse for the inverter. On the first picture, it's the green component just to the left of the word DIP.

PlainBill

[alexanna]

Re: Samsung SyncMaster 226BW

Your soldering is repairable; I had problems when I first started.
Getting good contact of the capacitor leads and solder pads is critical.
One thing I always do is to gently rock the capacitor and watch for any movement on the solder pads.
The inverter fuse is just to the left of the word “DIP”.
Fuses should read very close to 0 ohms resistance.