Samsung 2233sw '2sec to black'. Need guidance please.

[8ternity]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

HI Everyone,

I had the same issue that all the other person. The Monitor open, then after 2 seconds, the panel turn off, but the monitor led still get blue "on".

Im quite not a lot of knowledge then many people here, but where i can find the remplacement for the transformator?

I had an multimeeter and a capacimeter for mesuring capacitor when unsoldered. Im equiped also with an digital 90w solder station would like to know how can i fix this power board too? I can mesure all capacitors, but for the technical language and testing regarding the mosfet, i dont know how to test a mosfet (during power or need to unsolder to mesure and test it).

I will post some pictures tonight too to show power board and show you that the power board is look like overheating too (yellowing starting Under the power board).

Thanks to eveyone for all détails and help.

8ternity -- Montréal, Canada.

[retiredcaps]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Now, i can't find the ap4506geh

AP4506GEM are on ebay. The seller is a badcaps member here too.

http://www.ebay.com/itm/190459921505

$6 for 4 chips + $3 shipping from Florida.

[preface]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

my 2233sw inverter board photo.

the backside overheated around the ap4206geh so i changed it with 2 ordinary mosfets connecting the D legs together.

[preface]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

my ap4506geh was burnt. so

Having recapped the main 220vac->300vdc capacitor and all samyoungs + both on near the ap4506geh

transformer both secondaries = 890 ohm.

Now, i can't find the ap4506geh so i replaced it with other to-220 type mosfets, but to no avail. I think there is a specific value both in the ccfl startup phase and continuous operation that the BD9893F is measuring on the COMP (leg 9).

according to my osciloscope hookup as attached in the pictures, there seems to be a spike in return voltage to the comp leg that shuts it.

What are the main reasons that cause the BD9893F to decide either to continue after the 2sec startup phase or to stop all together.

I do understand that the 20seconds off then 2seconds on seems to be a thermal command, but then how could it reach its TJtemp within 2 seconds and shutting down a neat 20 seconds each time make sense?

At this moment I'm more interested in the BD9893F COMP leg that senses
IS COMP detect voltage 0.45-0.55v
SS COMP detect voltage 2.0-2.4v

this means that any irregularity that arises out of changing substitute components in the mosfet circuit driving the transformer that causes a drop/spike feeding back to the COMP leg will inevitably mean that either finding components with closes rating or forgoing the above? can anyone confirm this?..

Attachment note: (all 4 samples were taken at any time during the 2 second including more to the end of the 2 seconds. I'm using an uni-t digital oscy so if any one knows how to sample this 2 seconds and save it all to USB let me know)
Channel one measures the D1/D2 (drive legs of the AP4506GEH mosfet), this is the 20volts at about 40khz during startup phase that is driving the primary of the 700volt transformer.
Channel two measures the voltage level comming into the leg 9 of BD9893F (COMP leg).

The two channels are sync'ed , Chan one = 20volt resolution Chan two=2volts.

[PlainBill]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

My Samsung Monitor model 2233SW has similar problem. I would like trying repair myself. May I know how to disassemble the plastic mounting. Do you have any specific tips on the disassembly process?

This is covered in other threads, but the general process ggoes like this:

Lay a towel or similar material down on a hard flat surface such as a table. Remove the stand. Remove all obvious and hidden screws from the back.
Examine the monitor. There is usually a groove that runs all the way around it, this is where the front joins the back. Starting on the bottom, slide a thin tool* into that groove until you can determine which part overlaps the other. Continue working your way along the bottom, the catches will pop loose. Continue up the sides and across the top.

* There are many choices for the tool. I prefer a small screwdriver to start the process, then guitar picks to keep the parts separated. Others use a butter knife, putty knife, credit card, etc.

PlainBill

[msonline]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

My Samsung Monitor model 2233SW has similar problem. I would like trying repair myself. May I know how to disassemble the plastic mounting. Do you have any specific tips on the disassembly process?

[pavithra_uk]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

these tranformers can rewind if it it easily dissasembled, removing two ferrite core is very dificult due to glue used. anyone know a way to remove these glue without breaking core ?

[PlainBill]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Thanks PlainBill, so possibly a problem to do with the manufacturing of the transformer. Seems strange that the whole model is effected by this.
How safe would it be to use a different transformer? Would I just have to make sure I use a similar ratio of windings or are there other factors at play aswell?

One obvious other factor is the dimensions of the proposed replacement. Differences in the actual impedance of the transformers could be a problem.

PlainBill

[charithjperera]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Thanks PlainBill, so possibly a problem to do with the manufacturing of the transformer. Seems strange that the whole model is effected by this.
How safe would it be to use a different transformer? Would I just have to make sure I use a similar ratio of windings or are there other factors at play aswell?

[PlainBill]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Hey everyone,

I'm very sorry for the bump but I also have a Samsung 2233SW here that exhibits this same issue. I have removed the backlight transformers and the impedence for the secondary windings are 6K for S3 and S4 and open (>40MO) for S1 and S2.
I have ordered a replacement transformer as linked to earlier so many thanks for the detailed information and i'll let you know how it goes.

I was also wondering - what could cause these transformers to die like this?
Most (faulty) PS boards just blow cheap caps over time as you all would be aware but what what about this model could make them blow the transformer?

Could the CCFL lamps be too large for this transformer resulting in it overheating or something?

I'd really like to hear what you folks think.

Thanks very much!

There are only a few possible causes of a transformer going open. The most likely is poor manufacturing technique. Proper technique is to leave a small amount of slack at each end of each winding where it wraps around the post (this is a high stress area). As the transformers heat and cool the wire will be stretched at the post and eventually break.

Poorly annealed wire, or winding with too high a tension will also cause the problem.

PlainBill

[charithjperera]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Hey everyone,

I'm very sorry for the bump but I also have a Samsung 2233SW here that exhibits this same issue. I have removed the backlight transformers and the impedence for the secondary windings are 6K for S3 and S4 and open (>40MO) for S1 and S2.
I have ordered a replacement transformer as linked to earlier so many thanks for the detailed information and i'll let you know how it goes.

I was also wondering - what could cause these transformers to die like this?
Most (faulty) PS boards just blow cheap caps over time as you all would be aware but what what about this model could make them blow the transformer?

Could the CCFL lamps be too large for this transformer resulting in it overheating or something?

I'd really like to hear what you folks think.

Thanks very much!

[jetadm123]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

the transformer came & i replaced it. Also replaced most of the caps (minus the Big cap & the 2 small ones lying on their sides) with FMs & FCs..and.....

SUCCESS!!!.. ..

PlainBill, jetadm123, retiredcaps, Rtech, shovenose, POM_MJ, alexanna..
couldn't have done it without you guys... ..

Just a thought
>to Admin, can the Troubleshooting Computer Display section be sub-categorized according to the Brand of monitors, e.g. Samsung, Viewsonic, HP, Philips, etc.. like the mobo section.. I believe this will be easier for those searching for answers for their faulty monitors ..

ok.. 5 more LCDs waiting for my attention.. ..

Well done!!!! Always a pleasure helping you, since you go the extra mile in providing photos and a great description of your observations! Keep up the good work!

[newbie1]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

the transformer came & i replaced it. Also replaced most of the caps (minus the Big cap & the 2 small ones lying on their sides) with FMs & FCs..and.....

SUCCESS!!!.. ..

PlainBill, jetadm123, retiredcaps, Rtech, shovenose, POM_MJ, alexanna..
couldn't have done it without you guys... ..

Just a thought
>to Admin, can the Troubleshooting Computer Display section be sub-categorized according to the Brand of monitors, e.g. Samsung, Viewsonic, HP, Philips, etc.. like the mobo section.. I believe this will be easier for those searching for answers for their faulty monitors ..

ok.. 5 more LCDs waiting for my attention.. ..

[newbie1]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

thanks again guys. Will start ordering the caps while waiting for the transformer to arrive. Lets see how it goes.

[retiredcaps]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

"IF" (you will need to verify) two of the 820uf's were collected in parallel (meaning that the "+" leads of each cap share the same copper pad, then you would have a total of 1640uf). Since you're using twp 1000uf, you would have have a total of 2000uf, which is too high. Again, if they are in parallel, you could substitute a 680uf for one of the 1000uf, which gives you 1680uf.

Thanks for clarifying what I was thinking, but too hindered to type out on a 10 inch netbook with a tiny keyboard.

[jetadm123]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

thanks guys.. will update once i have replaced the transformer.. can i just leave the 3x Panasonic FM 1000uf 25v in place of the Samyoung NXB 820uf 25V?. or should i put the originals back?..

"IF" (you will need to verify) two of the 820uf's were collected in parallel (meaning that the "+" leads of each cap share the same copper pad, then you would have a total of 1640uf). Since you're using twp 1000uf, you would have have a total of 2000uf, which is too high. Again, if they are in parallel, you could substitute a 680uf for one of the 1000uf, which gives you 1680uf.

If you're going to go through all this trouble, go ahead and do what retiredcaps suggests and recap the entire board.

[retiredcaps]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

thanks guys.. will update once i have replaced the transformer.. can i just leave the 3x Panasonic FM 1000uf 25v in place of the Samyoung NXB 820uf 25V?. or should i put the originals back?..

Samyoung doesn't have the greatest reputation on this forum. Personally, I would still recap the entire board given this seems to be a nice 22 inch monitor.

[newbie1]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

thanks guys.. will update once i have replaced the transformer.. can i just leave the 3x Panasonic FM 1000uf 25v in place of the Samyoung NXB 820uf 25V?. or should i put the originals back?..

[retiredcaps]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Looks to be a greater than 3% difference between S1&S2, S3&S4. Suggest you start looking for a new inverter transformer.

$16 USD on ebay.

http://cgi.ebay.ca/TM-0815-Inverter-...-/150488882117

Seller is in Hong Kong.

[jetadm123]

Re: Samsung 2233sw '2sec to black'. Need guidance please.

Looks to be a greater than 3% difference between S1&S2, S3&S4. Suggest you start looking for a new inverter transformer.