Samsung 305T - Video Distortions

[gverrault]

Re: Samsung 305T - Video Distortions

I have a 305t plus that I'm thinking about trying to fix. I got a quote from a local TV repair shop to reflow the board for 25 dollars. I was then going to install one of the two following heatsinks. Anyone want to chime in on which one would work better.

1. Enzotech SLF-40

2. Startech FANCSCU

I'm just going to power the fan using a usb to 3 pin adapter for ease of installation.

[Need Help Fast]

Re: Samsung 305T - Video Distortions

Hi all, thanks for all the info!

I have a flickering 350T; I opened it up, found one bulging cap on the power board, replaced it, no difference. I'm about to recap the whole power board, but figured I'd post a video of what it looks like in case someone can give a better diagnosis. It looks perfect during the color test, then starts flickering and showing vertical lines when plugged in to a computer. This leads me to suspect that it's something that's on a board that only is relevant when plugged in (i.e. not the power board), but I think others here might have better judgement.

http://www.youtube.com/watch?v=akR5FujG2aU

Cheers!
Nevin

Hello Nevin,
I have the same exact problem on my 305T.
It was sent to Samsung who told me parts not avail and sent it back to me telling we they cant do anything about it.
Just curious what was your outcome?
I've read about reflowing the board in an oven.
That will be my last resort.
Please let me know what you did.
Thanks

[CdnGhost]

Re: Samsung 305T - Video Distortions

Hey I have the same problem obviously as everyone else... i had applied a heat sink worked for a few months but now the flickering etc is back... so qucik question about the Oven method...

What do i do about the plastic pats on the board? all the connectors? how do i keep them from melting?

Thanks

[Fursnake]

Re: Samsung 305T - Video Distortions

Hello all, long time forum browser, first time poster here. I have a Samsung 305T that I bought used off eBay and it worked great for many many months. Last night (Friday 13th) the monitor developed the rapid flickering that seems to indicate the problem with the chip itself.

As the Samsung 305t line has been discontinued by Samsung I have no illusion of hope of sending it to Samsung to be repaired.

At this point I am working with my dad (has a lot of electrical engineering and computer experience, way more than I do hehe) to try and fix it ourselves. I did the oven bake method for the board with the chip and we are at the point of working out a heatsink+fan rig for the chip.

I am thinking of digging through my old, out-of-date PC components and trying to find a graphics card and salvage a heatsink+fan off of one to use for the monitor chip. Barring that, anyone have any recommendations for heatsink+fan combos to use for this? Modding won't be a problem and I don't really care how it makes the monitor look aesthtic-wise.

I would like to say thanks to all of you for even having this thread here as this has been the only thread I could find that had really good information about fixing these nice but seemingly cheaply made monitors. FFS, Samsung!

[Fursnake]

Re: Samsung 305T - Video Distortions

Hey I have the same problem obviously as everyone else... i had applied a heat sink worked for a few months but now the flickering etc is back... so qucik question about the Oven method...

What do i do about the plastic pats on the board? all the connectors? how do i keep them from melting?

Thanks

The oven method will not melt those parts. I did the oven method of baking for 8 minutes at 375 degrees Fahrenheit and nothing melted. I used a method like lesterp from post #52, with a spring clamp wedged in the oven rack as you can see in his picture.

[Fursnake]

Re: Samsung 305T - Video Distortions

I can hardly believe it, it WORKED! Baking the mainboard in the oven did the trick. After baking and letting it cool off I put the monitor back together and it worked normally again. I left the back panel off and I could feel the heat that the main chip generated. There is really no heatsink aside from the little pad and the metal plate. I could also feel the main body of the monitor heat up good deal, could feel it in the metal parts.

I'm planning on getting a little heatsink+fan to attach to the main chip with some modding and probably going to mod the back panel by cutting holes in it big enough to fit some small case fans in there to help disperse the heat a bit.

This will be my first major mod project, I have some help via my dad who has electrical engineering in his background as well as computer stuff (he taught me how to put together my first computer). Actually he was skeptical about the whole oven baking thing, but after it worked he is fully on board.

Also, the talk about the capacitors in this thread helped me know what to look for as far as bad capacitors so thanks. They all seemed to be in good shape.

I'll post some pictures when we are done. It should look...interesting.

[Lumberjack777]

Re: Samsung 305T - Video Distortions

That's great! You guys and your oven method of reflowing are a lot braver than me. hahaha
The proper method would be to use an Infrared Rework Station; but who has the money for that?
What I use is a thermocouple and a heat gun. With some no clean flux squirted under the chip. Slowly heat it up to around 215 to 225 celcius. Then slowly bring the temperature back down.
You'll definitely need an active cooling system like that CPU cooler you mentioned; because that thermal pad pressed up against the metal just doesn't do the job. If the chip gets too hot for an extended amount of time it will crack the solder balls again (or whatever caused the lack of contact under the chip to begin with)
Good luck, and pictures would be great

[Fursnake]

Re: Samsung 305T - Video Distortions

Barely getting started on this so I'm not exactly posting pictures of the finished thing, but I would like to get some insight/advice on what I have planned. So here are some pictures of the proposed mod.

The planned layout. A small CPU heatsink+fan for the main chip located in the top middle. Two case fans on the left and the right to help disperse the hot air.




Going to cut a slot in the back plastic frame and the metal plate that covers the main board to attach the heatsink+fan directly to the main chip with some REAL thermal paste. I swear when I pulled the thermal pad off the main chip there wasn't really any thermal paste on there it seemed.



I think the trickiest part is going to be the power hookups. I have some different options to power all this. I could run a 6 pin cable from my modular PSU out a hole in the back and connect all the fans to that with apadters and such. The heatsink+fan has a 3 pin connector as does one of the case fans. The other case fan has a 2 pin connector. I also have a separate USB hub expansion card in my PC. Perhaps I could hook up the fans to that with some kind of USB adapters.

Well got some more online searching to do before I really get going with it. I want to make sure I have the right power setup before I finalize the modding.

[ekpyr]

Re: Samsung 305T - Video Distortions

Just wanted to add a success note here:

Baking the main logic board at a pre-heated 385 degrees fahrenheit for 8 minutes solved the problem for me. It took all of 30 minutes to disassemble, bake, and reassemble.

Thanks to everyone here for pointing the way.

[Behemot]

Re: Samsung 305T - Video Distortions

I had some interesting story with one motherfucker who tricked me supposedly doing reball while he did only BS - will deal with him one day - but after true rebal, works fine. Waitring for adhesive thermal pad now to glue heatsink on it.

Strange thing I noticed, it was only slightly warm even without any heatsink, contradicting everything I've read. I think reball and some small heatsink may be very well just fine. I also did some strange stuff with large fan, seems to be pretty worthless now…

[NMSwede]

Re: Samsung 305T - Video Distortions

Another baking success story... I had similar issues, my 305T would work just fine, after about 5 minutes of running, it'd just plain go blank black. Restarts, etc, just wouldn't do anything. No distortions or things like that, just black. I could see the backlight still on, but that's about it. Read this forum, and decided to go ahead and do the baking. It turned out just fine and dandy. I cut a hole in the back of the monitor, added a heat sink with a fan, and now it's been running for 3 hrs straight with no problems. I've had this bad boy packed in its box for over a year, and I'm so glad I finally got on here to set things straight again!

[sym]

oven baking worked! thanks guys. w00t w00t

I tried to reflow twice in the oven with no success. Then bought 5oz of Kester 951 No Clean Solder Flux off ebay for 6 bucks. It came with a little pipette to apply the flux. Wrapped in aluminum foil with a square cut out around the processor. I placed the board on 4 little foil balls to keep it off the tray. Baked for 5 minutes at 350 F. 305t+ is working again. I'll look into getting a heat sink.

[Behemot]

Re: Samsung 305T - Video Distortions

Really, is that so much of a problem to send it to somebody for reball? All that baking, OMFG, that's insanity.

[KLuuppo]

Re: Samsung 305T - Video Distortions

Hello to the forums!

I'm trying to fix one of these monitors. I baked the board but unfortunately melted the 15-pin data cable (guess foil isn't that great of a heat insulation). I already ordered the parts for new cable but I was wishing if someone could confirm the pin order of the cable ie. pin 1 is pin 1, 2 is 2 and so on. Thanks in advance!

[KLuuppo]

Re: Samsung 305T - Video Distortions

Answering to myself: the cables pinout is actually 1-15, 2-14, 3-13 and so on. So if you have the connectors facing the same way they are mirrored.

[xbliss]

Re: Samsung 305T - Video Distortions

I disassembled my 305T and removed the video board. I sent it to a reballer who removed the ALTERA chip, replaced its solder balls with 63/37 leaded solder, and reflowed it. I paid about $50 for labor + shipping.

I reinstalled the video board and the monitor worked perfectly for ~48 hours. Then it began exhibiting problems again -- vertical bands of color somewhat like a TV test pattern.

I don't blame the reballer. He had no way to test his work. We both knew that, and we agreed that he'd do his best. He offered to rework the board again at no charge, but I decided that I'd try a different approach.

I sent the entire monitor to Amkotron in Southern CA (they do Samsung's warranty service, and they're nearby). Amkotron has a mixed reputation, and I was hesitant about dealing with them, but they repaired the monitor quickly and returned it in perfect physical condition. That was 30 days ago. It's been working fine ever since.

I'm not using any auxiliary cooling on the monitor. I may attach a small 12v fan and power it from the USB port, but the monitor isn't really running very warm. The hottest part of the case is the backside top at ~36 degrees C.

I have a 305t plus that I'm thinking about trying to fix. I got a quote from a local TV repair shop to reflow the board for 25 dollars. I was then going to install one of the two following heatsinks. Anyone want to chime in on which one would work better.

1. Enzotech SLF-40

2. Startech FANCSCU

I'm just going to power the fan using a usb to 3 pin adapter for ease of installation.

I came here from this forum link:
http://www.xtremesystems.org/forums/...-305T-is-dying

Its crazy how many people have been troubled by this.

I am considering getting that or similar SINK + FAN. Did you end up getting it and installing it? How did it work out?

[Behemot]

Re: Samsung 305T - Video Distortions

In my case the most lasting solution was getting supposedly new chips from alibaba and changing it. Even reball did not last more than half a year. The *new* chips were all scratched and everything but at least the one we swapped is still kicking…BTW the customer has second one which is working for many years now without any problem whatsoever.

[mnordstrom]

Re: Samsung 305T - Video Distortions

I am in the process of completing the baking/heat sink+fan fix for the Altera chip, and I've come across a small problem. During disassembly, I damaged one of the cables connected to the panel control board. Whoever assembled the monitor put a strip of glue on top of the connection, and it was impossible to remove the pins without wrecking the plastic on the end. Inserting each of the tiny pins by hand is beyond my ability, and I wouldn't feel good about the quality of the connection.

I believe that the best course of action is to simply buy a replacement cable. Can anyone tell me what the serial number is of this cable and where I might be able to buy one?



Thanks,
Matt

[mnordstrom]

Re: Samsung 305T - Video Distortions

I am in the process of completing the baking/heat sink+fan fix for the Altera chip, and I've come across a small problem. During disassembly, I damaged one of the cables connected to the panel control board. Whoever assembled the monitor put a strip of glue on top of the connection, and it was impossible to remove the pins without wrecking the plastic on the end. Inserting each of the tiny pins by hand is beyond my ability, and I wouldn't feel good about the quality of the connection.

I believe that the best course of action is to simply buy a replacement cable. Can anyone tell me what the serial number is of this cable and where I might be able to buy one?



Thanks,
Matt

Not sure if the picture uploaded correctly, so here is the URL:

http://tinypic.com/r/r85947/8

[mnordstrom]

Re: Samsung 305T - Video Distortions

Not sure if the picture uploaded correctly, so here is the URL:

http://tinypic.com/r/r85947/8

Sorry....last try

<a href="http://tinypic.com?ref=r85947"