Samsung 305T Plus issues

[jetadm123]

Re: Samsung 305T Plus issues

A little update on my part: replaced Tcon, problem fixed. I'll use the old board to experiment on reflowing the Altera with a cheap hotair soldering station

Unless the new board has some mod to address the heat issue, then consider adding a fan to provide additional cooling. Otherwise , you may be seeing the same problem all over again.

[budm]

Re: Samsung 305T Plus issues

Super glue gel works well:
http://s807.photobucket.com/albums/y...%20LTV-32W3HD/

[KuroNeko]

Re: Samsung 305T Plus issues

No new mod, just the same heatpads. I'll see about adding a silent fan - any power lines available (12v) on the inside that are easily reachable?

[azkurz]

Re: Samsung 305T Plus issues

Hi,

I'm also the owner of a roughly 4 year old Samsung 305T PLUS monitor that just recently started acting up. What happens is the picture goes away and monitor is black even though I see the power light of the monitor is on. Picture usually comes back after 5 minutes of waiting. I might be able to run for a few hours and then it happens again.

Has anyone had similar problems?

I also hear high pitch noise that changes depending on how i adjust the brightness which leads me to believe it might be bad caps on the power supply.

Do any of you guys know if a power board for the 305T would work for the 305T PLUS?

[KuroNeko]

Re: Samsung 305T Plus issues

Many monitors have high pitch sound when using the dimmer. It's annoying but not necessarily a sign of defect. Have you excluded your gfx card as possible cause by using another or a different PC?

[azkurz]

Re: Samsung 305T Plus issues

Many monitors have high pitch sound when using the dimmer. It's annoying but not necessarily a sign of defect. Have you excluded your gfx card as possible cause by using another or a different PC?

Hi,

Yes the graphics card is excluded unfortunately as well as all cables. Monitor works and then just stops working, on and off. I did have some flickering problems before this but it I thought that was due to the displayport to dual link dvi adapter I was using. Monitor is out of warranty so I just feel I want to give it a shot at repair before I bin it.

[KuroNeko]

Re: Samsung 305T Plus issues

It might be the same chip that gave me trouble overheating (Altera Hardcopy). If you have the equipment, try reflowing it. Once open, check the caps, some may need replacement as well.

Try and fix it if you can, it's well worth the trouble. Current batch of 30 inchers don't come close to this one.

[azkurz]

Re: Samsung 305T Plus issues

It might be the same chip that gave me trouble overheating (Altera Hardcopy). If you have the equipment, try reflowing it. Once open, check the caps, some may need replacement as well.

Try and fix it if you can, it's well worth the trouble. Current batch of 30 inchers don't come close to this one.

Will give it a shot and let you know how it goes.

[azkurz]

Re: Samsung 305T Plus issues

I teared one of the flat cables connected to the board: http://img694.*************/img694/3...aphotoview.png

Are they replaceable?

[ksjon]

Re: Samsung 305T Plus issues

I just wanted to let you know i heated the T Conn boards Altera chip on a heatplate. Up to 240c.

My monitor works again after this.

If it breaks again i will order a new board. It's about 200$ from ebay / china.

Thanks for a great forum!

[acornish]

Re: Samsung 305T Plus issues

OK, so I see posts on this topic, so hopefully I can ask a question or two.

So, my problem is a dead powerboard. Thanks to people on the site I have the schematics and such, but I am still stuck. Here is what I know:

-the board was dead, but so was the green torpedo fuse (2A/125V) on the center of the board near IC FSD211H
-I replaced the fuse with an identical new one, but as soon as I power up the boards, the fuse "pops", so the board is still dead.
-repetitive and close examinations of the board do not indicate any popped caps (no bulging from either end or leakage). Using the schematics I have check all the caps near FSD211, but all look good.

So, I am thinking something is shorting out, causing the fuse to pop, but I have to admit I am new at reading schematics and for the life of me I can't figure out where the short might be or what might be causing it. I am a new member so can't post images yet, but the schematics can be found a couple of posts back in a file called 305T[13].pdf (thanks again for posting that file-it really helped).

Anyway, any advice or direction would be appreciated. It is a great monitor and I would hate to toss it over something like an undetected short.

A

[jetadm123]

Re: Samsung 305T Plus issues

With monitor unplugged, set your meter to resistance and place one lead on pin 1 of FSD211H and place the other lead (one pin at a time) on each of the other 7 pins. If you read something around 10 ohms, then the FSD211H is shorted internally.

[acornish]

Re: Samsung 305T Plus issues

With monitor unplugged, set your meter to resistance and place one lead on pin 1 of FSD211H and place the other lead (one pin at a time) on each of the other 7 pins. If you read something around 10 ohms, then the FSD211H is shorted internally.

Thanks, I will give that a try and let you know what I find.

[acornish]

Re: Samsung 305T Plus issues

Thanks, I will give that a try and let you know what I find.

OK, I tried your suggestion and have a couple of things to mention. To begin with, I actually have TWO 305T monitors, one works and one is dead. They both have the same power board (#BN96-03938A).

However, the working board has the FSD211H chip shown in the schematic (8 pin IC). The dead board has a FSD210 chip (a 7 pin IC with no pin 6). I don't know if this is because someone "fixed" the monitor before I got it or not. According to the data sheet the chips differ as below otherwise they are the same:

211 210
On-state Resistance 18 ohm 32 ohm
Current limit 0.48A 0.3A
Power output 6W 4W

On the power board, pin 7 and 6 locations are connected by what looks like a little brick with solder on both ends (sorry-being new, I am not sure what this "brick" is called).

So, with that mentioned, I did the pin test you suggested and found the following:

Pin 2 0.1 Ohm
Pin 3 0.1 Ohm
Pin 4 5.5 MOhm
Pin 5 347 KOhm
Pin 7 0 or no signal
Pin 8 0 or no signal.

Does this suggest the IC is correct? Try as I might, I can't find a data sheet for FSD211H, only FSD210.

Again, any suggestions are greatly appreciated.

A

[jetadm123]

Re: Samsung 305T Plus issues

It appears the 210 and 211 chips have different pin configurations. From the schematic, pin 1(Vstr) of the 211 is connected to the fuse. I suspect that pin 8 (Vstr) of the 210 on your dead board is connected to that fuse. You'll have to verify this by tracing the path from the fuse to pin 8 of the 210. If true, then repeat the resistance test with one probe on pin 8 and the other probe against the other 6 pins. If you download the datasheet for the 210, you'll see it's normal for it to have 7 pins.

[acornish]

Re: Samsung 305T Plus issues

From the 210 data sheet it would appear that IC installed as a direct replacement for the 211 chip, that the fuse is not connect directly to ground. Pin 1 on 211 is the Vstr, whereas Pin 1 on 210 is a ground. Does that explain why the fuse keeps popping?

This would suggest someone tried to "fix" the monitor before I got my hands on it. It should also means that with a good 211 chip the power board may be fixed.

I tested the 210 chip as you mentioned with one probe on pin 8 and found the following:

pin 1 2.9 MOhm
pin 2 2.9 MOhm
pin 3 2.9 MOhm
pin 4 11.75 KOhm
pin 5 3.4 MOhm

pin 7 0

Does this suggest that pin 210 is OK? Not that it matters I guess.

If I can't get a 211 chip, could the power board still work if I ran connections from the appropriate pins on the 210 chip to the correct spaces on the board so that the Vstr, Vcc, and Vfb now go to the correct places on the board? I guess what I am asking is, are the two chips similar enough in specification and function such that the 210 can substitute for the 211 chip if wired correctly?

Last question (for now); any thoughts on where I could order a 211 chip? Obsolete best describes what I have found so far on line.

Thanks again for all of your help-A

[selldoor]

Re: Samsung 305T Plus issues

Dont think you will find a chip 211 some legal dispute see here https://www.badcaps.net/forum/showthread.php?t=18768

[jetadm123]

Re: Samsung 305T Plus issues

Since both your monitors have the same power supply, you'll have to do a careful compare of the circuit board traces of the "good" board to the one you're trying to repair. Also, make sure the external parts around the 211 are the same as on the 210 board. This will verify that whoever tried to repair the power supply did indeed substitute a 210 chip for the 211. Hard to say if the 210 can be used in place of the 211 even if you try to rewire it externally, since there seems to be no 211 datasheet to do compares.

[selldoor]

Re: Samsung 305T Plus issues

This might be of interest - I have not compared datasheets but this version of the 210 comes in 7 and 8 pin with different pin config
http://html.alldatasheet.com/html-pd.../FSD210DH.html


EDIT
Building on FSD210 replaced by FSQ210 I notice this

http://html.alldatasheet.com/html-pd.../3/FSQ211.html

[acornish]

Re: Samsung 305T Plus issues

A side-by-side comparison does indicate that the board tracings are the same, all components in the area are the same. It would appear that the only difference was the change of the 210 chip for the 211 chip.