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Discussion Starter · #1 · (Edited)
Hi guys,

If I could add a couple of comments to this digital board problem as it seems to cover the entire gamut of pain and aggravation of dealing with defective products.
I bought a used HL-R4667W that seems OK at the seller's house. When I brought it home it did not
start right up, the lamp light blinked a few times then nothing. I read on some other
threads to try to unplug the unit for 30 minutes and replugging may solve some startup
problem. Did that a couple times and it seems to clear up whatever condition it was stuck in.
Ran the 1st day with no further issues.

The 2nd day I got what all you guys have been having fun with... the dreaded green plaid pattern.
It was strange to me as I have never seen it before, and it seems to be localized to low resolution displays, the HD's were OK. Very strange as it worked fine the previous day so I did the unplug/replug trick again and it seems to take 5 times before it becomes "normal" again. Watched a few shows then called it a day.

The 3rd day... green plaids AND lock up. Can not even switch modes or power off unit. Tried unplug/plug to no avail. Green screen is here to stay. Looked around on net, found earlier post on this site for various dealing with the problem, tried the manual screw pressing on DNIe chip with very limited success. The problem came back after switch off, very aggravating. Applied thumb pressure on the DNIe chip produce a slight crunch toward one corner of the chip, like the sound of a socketed chip being manually reseated... but this puppy is flow soldered ... hmmm, not a good sound.

By now screw pressing down and power resetting have zero effect. Unplugging the video input from the cable box produce the clear blue screen with AV1 imprint so the display parts are OK. However, it now will consistently lock out after approx 5 seconds of the green plaid screen with no further screen updates.

Further reading into the flow repair service as well as the more spectacular alcohol bonfire on the chip, I agonized on sinking more money into this beast or ... read more on this flow repair business.

http://www.ifitjams.com/2008/08/reflowing-solder-under-bga-processors.html

This showed the "expert shop" repair next to the more flame-boyant alcohol filled candle dish repair.
Others also mentioned putting coins/other metal objects to transfer heat to the chip with somewhat
mixed results. I chose the best of both or rather the first half of the expert repair.
Reasoning: why take off the chip and reball the joints, the initial process already does what's needed: melt the solder joints under the chip.

Looking further yielded some useful info from this site which have the flow resolder temp/time graph:

http://forums.macnn.com/69/mac-notebooks/210232/diy-ibook-dual-usb-logic-board/

which used info from this:

http://www.altera.com/literature/an/an081.pdf

I now got enough info to attempt my own flow repair. I got all the required items:
Heat gun, aluminum foil, infrared temp laser gun, egg timer, and solder flow timing diagram.
I'm going for it.

From the "expert" video:
I put the board on my ceramic tile kitchen table top for heat resistance.
Covered the board with aluminum foil. Pushed down around the chip to see outline and
gently rake the foil along the chip outline.
Took the foil off and fold along the corners of the cut out and trimmed and additional 1/8" off
to expose some board area around the chip. (This is done to warm up the board area under the
chip thus reducing topside temperature required to flow solder)

Keep in mind these are in Centigrades and not Farenheits.
From the solder flow repair diagram, it would take approx 5 minutes to do:
1 minute to get the chip to 150 degrees C
2 minutes to increase from 150 to 183 degrees C
1 minute to increase from 183 to 220 degrees C (do not exceed this for case temp or you fry the chip)
1 minute to decrease from 220 to 183 degrees C
Removed heat and allow to air cool untouched for 15 minutes.
Checked with thermometer to make sure temp is OK to handle part.

First, the bad thing that happened: the foil had transferred heat to the plastic plugs it was resting on
thus deforming 2 board side plug housings. No scorching or shape change on the user plug ends.

Plugged the board back in, fired it up and wonder of wonders, the TV stepped right through the
lamp scan, go right to the melody start up, and no more green plaid screen!!! Source switching worked!
Unplugged TV, put all the covers back on, plugged all the cables/antenna from various sources , plugged back in and ALL of them displays correctly.

I would say the key is proper temp monitoring and timing, not too hot and not too long. Also observe the warm up and cool down change limit, not too fast... 1-3 degrees C per second.

For those less inclined, sending it off to reflow will be less stressful.

Thanks for all that isolated the problem and formulated the fix, you guys are awesome!

:clap::T:clap:
BTW: Sorry guys, could not include any web pointer as a newbie.
 

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Your post was moved to a new thread to maintain forum organization and to make information easier to find. It was not concluded that the thread you posted in was related to this problem, and your information might get lost in another thread.

Please include the links when you reach an adequate post count.
 

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I am about to send my board in to JD Electornics for reflow. For anyone that has already done this, do I need to tell them which chip to do, or do they know? I saw one post where a guy said they found a couple additional chips needing reflow, and did those too. I guess I can just tell him to do the DNIe chip, and then to let me know if he finds anything else needing attention?

Also, I assume everyone sends the board in its metal housing, for protection? I pulled out the screws that hold it together and took off the 2 nuts on the coax plugs, so all he would have to do is pull the board out of there.

Thanks!
 

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Discussion Starter · #5 ·
Hey Jayfore,
Sounds like you got the gist of the requirements.
I would leave the nuts/screws/bolts on the frame as it help keep the frame rigid during transport.
They know how to disassemble and reassemble the frames by now.:innocent:
 

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I am about to send my board in to JD Electornics for reflow. For anyone that has already done this, do I need to tell them which chip to do, or do they know? I saw one post where a guy said they found a couple additional chips needing reflow, and did those too. I guess I can just tell him to do the DNIe chip, and then to let me know if he finds anything else needing attention?

Also, I assume everyone sends the board in its metal housing, for protection? I pulled out the screws that hold it together and took off the 2 nuts on the coax plugs, so all he would have to do is pull the board out of there.

Thanks!
Ask JDE these questions, not third parties. They are the ones who will be doing the work. You should always have a clear understanding with a servicer regarding what will be done and what they need before engaging any service.
 

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Ask JDE these questions, not third parties. They are the ones who will be doing the work.
Called them this morning, and spoke with the person that will be doing the work. She told me that there is no need to mention which chip(s) need(s) to be reflowed, because (1) they are very familiar with this particular board and issue, and (2) they reflow all the chips on the board. I found the last point interesting, as the price I was quoted was $25 and I remember seeing another post where someone paid more for additional reflows on their board. They mentioned that shipping in the shiny cage that the board sits in, with or without the screws, is fine.
 

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Is it $25 flat rate or $25 if it does not work? Last I remember hearing is that they were charging $75 and if it did not solve the problem $25.
 

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Is it $25 flat rate or $25 if it does not work? Last I remember hearing is that they were charging $75 and if it did not solve the problem $25.
$25 was the price I was quoted. I think it was a lot more if the work was paid for thru Ebay.

Here is what was emailed to me:
Re-flow works about 90% of the time. If a re-flow dosnt work then it is usually a defective IC or needs reball. You can re-flow an IC twice with no problems. The price of re-balling is over $100.00, which rivals the cost of of replacement. At $25.00 + return shipping we just re-flow, inspect but don't test, and send back.
 

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Hi tnk2k,

Just wanted to extend a big thanks for your comprehensive information. I just went through the reflow process with my HLR-4667W. The green plaid effect has been coming and going for almost two years now, which was increasingly frustrating when attempting to use the TV for anything (especially when company was over). I even cobbled together a HTPC to use for OTA HDTV tuning and DVD duties (the PC input on the TV wasn't affected by the issue), but finally decided to bite the bullet and attempt the fix. If I fixed the TV, that would be cool, but if I destroyed it, that was OK too, since I would just buy something else!

Fortunately, I had access to a really good heat gun and a thermal imaging camera (Fluke Ti20). This made the temperature monitoring pretty straightforward, though I did hit 221.3 degrees at the high point of the reflow. It didn't seem to fry the chip. After reassembling as little as possible to get power to the unit, I discovered that everything worked perfectly well, with no green plaid, lock-ups, or other issues. Amazing, considering the less-than-scientific methods employed.

One problem that we both seemed to have was the heat transfer to the plugs closest to the DNIe chip. Therefore, I recommend that a couple of layers of foil be used to insulate the plugs. My optical digital output port was slightly warped by the process, but all I had to do was use a pair of needle-nosed pliers to remove the little spring-loaded "door" over the port, and everything else was OK.

It is probably far less stressful to just ship the digital board off for the reflow, but if you have the tools and the patience, it can be done from the comfort of your home!
 

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Update:

Well, that didn't last too long. I turned on the TV this morning and was very displeased to see the green/purple squares again. I'm not sure if there are varying degrees of this issue, but the screen artifacts were minimal this time. It was almost as if this is the beginning of the same downward spiral.

I briefly considered executing a vertical suplex against the set, but decided against it and once again cracked the case. I jumped the case switch and fired up the set with the back off, and watched the general area of the digital board with a thermal imaging camera. It seemed to get pretty warm, even with the back removed. I can only assume that the temperatures would be substantially higher with the set fully assembled and/or after several hours of operation (e.g. during Stanley Cup finals). So maybe, just maybe, the temperature of the DNIe chip during operation is sufficient to stress the BGA solder points.

As I am unwilling to spend even one dollar to fix the set, I decided to build a clamp to apply uniform pressure across the chip. I trimmed down a heatsink from an old graphics card, and used a potpourri of screws, washers, and nuts to hold the heatsink down at the edges. The whole operation (tear down, clamp, assemble) took about an hour. After reassembly, the set resumed normal operation, with no artifacts. It may not be a Samsung-approved fix, but it appears to work. Plus, it didn't cost me anything beyond the time and aggravation.

Good luck to everyone else fighting this issue.
 
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