Mitsubishi LT-55154 Blinking Green Light?

[captain-joe]

Re: Mitsubishi LT-55154 Blinking Green Light?

I have a LT-55164 where the YPbPr component video inputs work and NO hdmi inputs work.

I've replaced the HDMI processor chip (IC2A01) and no improvement.

I'm a little hesitant to reflow the GPU's since I do have a working TV (although no HDMI)

When you re-flowed the GPUs, was it because of the HDMI not working or did you have other issues?
Thanks

[Michael Long]

Re: Mitsubishi LT-55154 Blinking Green Light?

No mine was worse... Green Flashing LED of Death.
TV would not boot... I recapped the board with new Panasonic Electrolytic CAPs = NO JOY. I replaced Eeprom = NO JOY. I reflowed GPU as well as well as the two adjacent surface mount chips = JOY TO THE WORLD. I then added JB Weld ( Epoxy ) to the four corners of the GPU and added a 35 x 35 x 10mm ball bearing 80,000 mtbf Fan to the GPU Heatsink to create an active cooled cemented GPU instead of the passive held on by solder. This should avoid a repeat failure. I thought I saw a post that the GPU can affect HDMI... I have been running the TV continuously for over a week with Blu-ray DVDs and the GPU heatsink is cool to the touch, opposed to the original condition after my repair where it was warm to hot. The power source I used was the +5V and GND used for USB ( Power Only ) the feeds on the back of the MAIN-PWB and I passed the cable through a hole in the middle of the board. The fan will shut down after TV is turned off and USB port times out.
That's my story. ( Hope this helps )

[rockola1454]

Re: Mitsubishi LT-55154 Blinking Green Light?

Michael, you (and Nyjetfan21) are a genius for figuring this out! I believe I have the same exact issue, my green blink symptom is the same and all suspicious caps have been replaced with good ones. Did you need to remove the chips before performing the reflow, or just heat them up as they were?

I have never attempted to perform a reflow on a GPU/BGA chip before, but if you happen to know of any links or tutorials that could help me perform the same operation you did (what equipment I need, the general process, temperatures, heat times, etc.) I would be very grateful! I'm eager to learn new tricks

[rockola1454]

Re: Mitsubishi LT-55154 Blinking Green Light?

Update: my LT-55164 lives! I studied some videos on how to reflow chips, and picked up some liquid flux and a X-tronic reflow solder station. Performed the operation on just the Broadcom video chip, using some Sekisui thermal tape to re-affix the heatsink. Turned it on (thinking in the back of my head, no way this will work), and voila! Been using it for a couple weeks now, and haven't noticed any issues.

I also attached a small fan on account of how unbelievably hot the heatsink gets after only a few minutes of on-time. Tied it in to a 12 vdc feed from the power supply, and got lucky in that the 12 vdc turns on and off along with the TV. Decided to cut a ventilation hole in the back and covered with a gutter shield... it's not pretty but it runs cool now!

Again, MAJOR THANKS to Michael Long for the info, my TV would still be collecting dust

[ayazshah1982]

Re: Mitsubishi LT-55154 Blinking Green Light?

Michael Long you are genius. I had no HDMI 1st (TV was working fine) and later down the road yellow blinking light. Today i re-flow all 3 chips with heat gun (same as PS console) and all my problems got resolved (including HDMI). Thanks again u all

[Mazdaspeed]

Re: Mitsubishi LT-55154 Blinking Green Light?

Just want to jump in an say thanks for this really useful thread. Yesterday I gambled $50 on a LT-46164 that had the GBLOD. I went ahead and ordered new CAPs on Amazon for delivery, today, but when I opened it up last night the CAPs looked fine.

After reading through this thread I figured the reflow was my best bet, but didn't really want to use the heat gun. A little more research found a tried method for recovering laptop mainboards with failed GPUs, and it did the trick for this Mitsubishi. Simple as this:

1). Pre-heated my oven to 385 degrees, pulled the LT-46164 mainboard, wrapped aluminum foil around its outside edges and also covered the audio jacks.

2). Next, I rolled 4 foils balls about an inch in diameter, arranged them on a cookie sheet, then placed the mainboard on the balls.

3). Into the 385 degree oven for 8 minutes, then carefully opened the oven door a few inches, shut the oven off and went to bed.

4.) This morning I re-installed the mainboard, plugged the power cord in, watched the green light start flashing, had a doubting few moments, and then the green light went completely off.

5.) Pressed the power button, watched the screen come alive, entered into the service menu with the remote, checked that I still had the correct screen size configured, did a full initialization, scanned the channels and started enjoying one of the finest LED screens I've laid eyes on.

Some thoughts and advice:
------------------------------
Use the Service Manual for troubleshooting and clarity, before doing anything else. I've attached it to this post.

When heating the mainboard, make sure you don't bump the stove or have the kids jumping around.

Once the solder is at flow temperature any movement could leave you with a paperweight.

Also, movement during cool-down could leave you with cold solder joints, and even though it might initially work, it may quickly fail. I woud give it at least 45 minutes to cool.

The idea behing using the oven is gradual heating and cooling, so don't even consider pulling it out of the oven until you are sure the solder is set. All my solder joints looked absolutely fresh when I pulled it out of the oven.

I thought about waiting and replacing the CAPs for good measure, but they honestly looked fine. After seeing the service menu showed over 17,000 hour of usage, I think it might have been a worthwhile effort.

Once operational, make sure you go through the initialization process, as this brings everything into sync across ICs and control circuits.

Here's the Mitsubishi resource page for all manuals and firmware updates, except the Service Manual:
https://www.mitsubishi-tv.com/suppor...ments/LT-55164

Here'a a decent resource about replacing CAPs, if needed:
https://techlore.com/article/mitsubi...pair-procedure.

My hunch is that in the absence of obvious CAP failure, a reflow is going to be the ticket, and not just for Mitsubishis. Once inside, you'll see it's all Samsung components, anyway. If the power supply is the culprit I do believe you will see and smell the effects of its failure.

The reflow is primarily aimed at the GPU, as this is where excessive heat begins to degrade the solder, causing a microscoppic honeycomb effect which further increases resistance and heat. It simply becomes a digressive loop for heat failure.

The original Xbox was notorious for a BGLOD, and it was the GPU causing the issue, so the reflow of this TV's GPU made a lot of sense to me. We always replaced the heatsink compound to fix the Xbox, and a reflow would have probably been a good measure as well.

Cheers!

[Mazdaspeed]

Re: Mitsubishi LT-55154 Blinking Green Light?

UPDATE:

When I went to connect analog audio cables I found that the 385 degrees had caused the RCA jacks to expand, thereby causing the hole size to shrink. Quick fix was to drill the RCA holes back out to 1/8" while applying suction from a vacuum hose.

[rynodav]

Re: Mitsubishi LT-55154 Blinking Green Light?

I followed Mazdaspees's instructions for a Mitsubishi LT-55164 main board and it worked! The TV had a fast blinking light. After cooking it in the oven at 385 for 8 minutes and letting it sit for a hour to cool, I put it back in the TV and it worked! This was my grandparents TV and they smoke, all the components had a nicotine film on it. Im not sure if this messed with the performance of the TV or not. I also cut a hole on the back of the TV over the main board for ventilation. I have not installed a fan yet.

Just wanted to give a shout out to Mazdaspeed and others on this thread for all the help!

I have another TV im going to try this on.

[Mazdaspeed]

Re: Mitsubishi LT-55154 Blinking Green Light?

Heads-up... My fix worked for about 2 months and I’m confident it can still be repaired, but I haven’t taken time to do it. Little by little it would take longer for the TV to come on, from the time of pushing the power button. I assume this is due to weak capacitors so my plan is to replace them, especially since I already bought them.

Nevertheless, I will be using this oven reflow method on future electronic fixes when it seems it would be appropriate. Wish I had known this trick when I was repairing 1st Gen Xboxes.

[TeenyWenis]

Re: Mitsubishi LT-55154 Blinking Green Light?

Just followed Mazdaspees's instructions for my LT-55164 that wouldn't turn on with green light of death for the past couple days. It worked perfectly and I can't thank you enough! When I first started it up it was blinking green but it turned off after a few seconds. Can't believe it worked lol.

[Mazdaspeed]

Re: Mitsubishi LT-55154 Blinking Green Light?

Yeah, baking your HDTV back to life has to be one of the most gratifying experiences of all time!

[SDR1290]

Re: Mitsubishi LT-55154 Blinking Green Light?

I too just followed mazdaspeeds instructions and to my amazement the TV came back to life! Thank you all for sharing your brilliance! I hope it lasts for a while.

I did have some melting/distorting of the black plastics around the av ports, etc despite covering with AL foil. Minor problem.

Prior to putting the back cover on I decided to cut some air vent holes above and below the heat sinks on the main board for good luck.

Thanks again.

[Mazdaspeed]

Re: Mitsubishi LT-55154 Blinking Green Light?

As mentioned in my tutorial, distortion of any/all of the rca connectors can be expected. This is probably unavoidable related to the material specifics within this particular Mitsubishi design, that being the plastic’s melting point is probably near the 385 degrees. I drilled the plastic rca holes to 1/8” and the fit was very tight. The rca pin specification is 3.7mm, so the closest SAE size is 9/64”. 5/32” is over 3.7mm and would risk causing a poor connection.

[k4x4map1]

Re: Mitsubishi LT-55154 Blinking Green Light?

Thanks to all that posted the most sensible repairs online. After reading through a few posts in justanswer.com/tv, one of them struck me as odd. The technician stated to heat up the main board with a hairdryer. The client responded to say their tv now worked. Wanting to learn what he (technician) was actually heating and why, I came across this site. I wouldn't go as far as to use my only oven, so with the information here, I learned what chip (Broadcom) to heat up and why. After learning about reflow and watching another youtube video, as the tech repaired a laptop with no video, I figured I was close. To the point, I heated the Broadcom chip with the heat sink still attached and monitored the temperature with my digi temp tool. Started at 8 inches away and got real close to the board (210F) I think was the highest temp with the heat sink; I also laid a pair of oven mits over the exposed areas. Didn't think I did anything, so I reinstalled the main board and conducted several more hours of research looking for the best caps to test. Got real tired of that so I said okay plug the set in and test them all. This time I turned on the set, waited almost 15 minutes and when I returned to the set, just out of curiosity I looked and saw that the BGLOD was extinguished! Whaaaat?! Pressed the power button, and wallah! Plugged in my laptop via HDMI and double wallah! I checked the Broadcom chips' temperature (approx. 15 minutes) and it was already at 103F (w/o the heatsink). So, I had already ordered the fan as previously suggested, and a pack of thermal heatsink copper pads. I will place a thin copper pad (.3mm I think it is) between the chip and heatsink with silver compound thermal CPU compound paste. All for a free TV the neighbor was literally throwing away! Now I'll order the remote. Again, thanks for the posts as this site sealed the deal!

[SenseofScale]

Re: Mitsubishi LT-55154 Blinking Green Light?

To add to the pile of "it worked!", heating the graphics chip also worked for an lt-40164 that picked up for next to nothing. I didn't use an oven. I have a cheap temperature controlled hot air station that I used to focus the heat on the chip itself.

Anyone have any updates on the permanence of this fix?

[Nyjetfan21]

Re: Mitsubishi LT-55164 Blinking Green Light Is Back?

I have a Mitsubishi LT55164 that I repaired almost 2 years ago due to a constant blinking green light. Well guess what it happened again The same blinking green light . I did also install an internal fan that constantly runs even when the TV is powered off . So now I'm back to square one where I have to reflow the GPUs and reinstall the heat sinks . The one question I have is how can I install the fan where it only powers up when the TV is turned on and don't have to run constantly like it used to . Does anybody have a diagram or a video to show me how to wire the fan in and only power up when the TV is turned on thank you

[R_J]

Re: Mitsubishi LT-55154 Blinking Green Light?

What are the specs on the fan? is it a 120v ac fan or a 12v dc fan. or something else?

[nomoresonys]

Re: Mitsubishi LT-55154 Blinking Green Light?

Ran across this fan mod, I don't know if this would put extra stress or have any adverse effects on the circuit or not. I should think the best way to use 2 case fans for cooling would be one towards the bottom drawing air in and one towards the top exhausting the hot rising air out: https://www.youtube.com/watch?v=wRrHL-em854

[nomoresonys]

Re: Mitsubishi LT-55154 Blinking Green Light?

"Smart strip" could be an alternative for the less technically inclined: https://science.howstuffworks.com/en...wer-strip1.htm

[Michael Long]

Re: Mitsubishi LT-55164 Blinking Green Light Is Back?

I installed fan on the GPU... Multi Volt Fan 3 v - 12 v running at 5 v... on the USB Circuit... See Image above for FAN Mounting. Fan was also a 80,000 hour MTBF
I also Re-flowed the GPU and Epoxied the four corners... My GPU now runs ICE Cold..
The 5 volt USB circuit will time out and eventually shut down...