Samsung SyncMaster 204BW

[Ritalin]

So I got this monitor free off of craigslist and it's been a pain in my side since day one. (Guy was an hour late for meeting, grrrrr). Anyways, it was dead'er than a doornail when I got it, replaced all major caps since some were buldged, and checked the power coming out and everything seems to check out. Put it back together, worked for a little bit, and then nothing.

Open'ed it back up and caps were ok, power still the right amount, so now I suspect the CCFLs or the inverter board and this is where I get stuck, cause I don't know what to check now.

Suggestions?

PS - Why did my pictures get re-sized so small? :s

[smason]

Re: Samsung SyncMaster 204BW

Wow nice lighting, did you use studio lighting equipment or something?

The best way to check inverter/ccfls is to substitute one or more known-good bulbs and see if they light.

[Ritalin]

Re: Samsung SyncMaster 204BW

Wow nice lighting, did you use studio lighting equipment or something?

The best way to check inverter/ccfls is to substitute one or more known-good bulbs and see if they light.

I made a little 'ebay booth' which I take pictures, it's pretty craptastic now, but I made a 3-D design on sketchup of what I plan on making this summer.

I do have a few LCDs that have cracked screens, could I use those CCFLs even though they are not the same size?

[smason]

Re: Samsung SyncMaster 204BW

I've been meaning to set up some diffusers for photographing boards, since I have like 5 strobes and 3 radio triggers. Just haven't gotten around to it yet.

Yes, you could probably use them for testing even if they're different sizes, I suspect the current draw would be pretty close, close enough for testing..

[EGuevarae]

Re: Samsung SyncMaster 204BW

Nice pictures. Way off topic, but can you show the booth?
As for the LCD, I go for the lamps ...

[Ritalin]

Re: Samsung SyncMaster 204BW

Nice pictures. Way off topic, but can you show the booth?
As for the LCD, I go for the lamps ...

lol... no worries about going off topic... Do you want my current booth or the one I'm going to make? Cause if it's the one I'm going to make I haven't copyrighted it and going to sell for millions.. (JK)...

Ya.. I have a 19" widescreen that is cracked that I'm going to use to test to CCFLS, never done it before, so if I don't respond tonight, you know something went wrong...

[PlainBill]

Re: Samsung SyncMaster 204BW

To bring the thread on topic, here's a couple of points.

1. It would have been really helpful to have a picture of the back side of the power supply / inverter.

2. Please don't post pictures inline. They slow down loading, and generally inconvenience everyone. Use 'Manage Attachments' below the text entry area.

3. Fully explain 'Worked for a little bit and then nothing'. Very few of us are mind readers.

And yes, they are excellent pictures.

PlainBill

[Ritalin]

Re: Samsung SyncMaster 204BW

Sorry, I thought I posted both pictures of the back of the power board and inverter, but missed the power board. And I never knew about the attachment manager, so thanks for the heads up on that. I'll try clarifying more tomorrow when I'm not half a sleep and stressing out about driving in 4-6" of fresh snow

[PlainBill]

Re: Samsung SyncMaster 204BW

Sorry, I thought I posted both pictures of the back of the power board and inverter, but missed the power board. And I never knew about the attachment manager, so thanks for the heads up on that. I'll try clarifying more tomorrow when I'm not half a sleep and stressing out about driving in 4-6" of fresh snow

Ahh, fresh snow. Well, at least by now drivers have reestablished their 'winter driving' reflexes.

The legend for the connector (CN2) for the cable linking the two boards isn't clear. I can identify On/Off, what I presume is brightness, +13V, what should be Gnd, but the closest one eludes me. What is that, and what are the voltages on each section?

In teh inverter section is a 28 pin IC. What is the part number of that?

PlainBill

[Ritalin]

Re: Samsung SyncMaster 204BW

Ahh, fresh snow. Well, at least by now drivers have reestablished their 'winter driving' reflexes.

The legend for the connector (CN2) for the cable linking the two boards isn't clear. I can identify On/Off, what I presume is brightness, +13V, what should be Gnd, but the closest one eludes me. What is that, and what are the voltages on each section?

In teh inverter section is a 28 pin IC. What is the part number of that?

PlainBill

I just checked the voltage and I do have 5V coming into the inverter board and I have 3.324V coming out of the regulator. But I couldn't remember what this computer was doing and hooked it all up again.And I'm not getting it to power on, the LED doesn't even come on. And I'll have to tear it apart again to get the info Bill.

EDIT: While I was taking it apart a cable wasn't in right, and this time the blue LED is on all the time, but still nothing shows up on the screen.

[Ritalin]

Re: Samsung SyncMaster 204BW

Here ya go Bill! I am getting 13V out of the 13V section, but I also tested the O/F and I'm getting ~0.022V even though the LCD panel or the connector to the power button is not plugged in. Should I be getting 3.3V? or since I don't have those two things connected it doesn't matter at this point.

And I just noticed that one of the LCDs that I fixed a month ago is sitting in my LCD collection is a 204B, so I think I could use that to test the parts to see which is failing.

[Ritalin]

Re: Samsung SyncMaster 204BW

Any thoughts?

[Scenic]

Re: Samsung SyncMaster 204BW

interesting.. my Syncmaster 223BW with the Mendel_VE LCD controller board (yours being Mendel_Normal) is doing pretty much the same thing. all voltage regulators on the LCD controller board work fine and all PSU voltages are up and stable..

but the monitor is still dead as a doornail.. Oo

[PlainBill]

Re: Samsung SyncMaster 204BW

Any thoughts?

Darned few. Well, .022 volts is 'Off'. I would suggest you hook the power button up to the signal card (logic card) and see if the voltage level at O/F ever goes to 3.3V.

PlainBill

[Ritalin]

Re: Samsung SyncMaster 204BW

Darned few. Well, .022 volts is 'Off'. I would suggest you hook the power button up to the signal card (logic card) and see if the voltage level at O/F ever goes to 3.3V.

PlainBill

Hooked the monitor up like shown below and got 0.033V.

[PlainBill]

Re: Samsung SyncMaster 204BW

Hooked the monitor up like shown below and got 0.033V.

Does the power light go on and off when you push the power button?

PlainBill

[Ritalin]

Re: Samsung SyncMaster 204BW

Does the power light go on and off when you push the power button?

PlainBill

As soon as I plug it in and hit the switch, the power light is solid blue and when you press the button, nothing happens.

[PlainBill]

Re: Samsung SyncMaster 204BW

As soon as I plug it in and hit the switch, the power light is solid blue and when you press the button, nothing happens.

Somehow I seem to remember your already having said that.... Sorry for my lack of attention. So we have a 'dead signal (logic) card' problem. I can identify two voltage regulators on the board. It's time to check them.

Refer to the picture in post number with the two signal input connectors closest to the camera. There is a white 4 pin connector at the left edge of the board in that picture. Presumably that is the connector for the front panel. Just to the right is an APL1117-18. That should be a 1.8V LDO regulator. Just 'South' of the 4 pin connector is the 3.3V LDO regulator. Using any good ground point, measure the voltage on the two complete legs and the tab (the stub leg is electrically connected to the tab) of each regulator.

PlainBill

[Ritalin]

Re: Samsung SyncMaster 204BW

Here is a closer picture of that area. Looking up the part numbers to know what leads do what. And I came across a possible missing resistor? Kind of hard to tell.

[Ritalin]

Re: Samsung SyncMaster 204BW

Updated picture w/ measured voltages.