How To Repair Blue Screen In TV
This Miyako CRT TV came in with the complaint of no picture, no sound and blue screen.
Blue screen seems to be a common fault for TV and the first thing I checked after opening up the cover was the DC supply voltage to the EEPROM IC and the System IC. Take a look at the photo below of the two ICs:
I checked on the EEPROM DC supply voltage and I’d got 5 volt and it was good.
The next step was to check on the DC supply to the VCC pin of the system IC.
5.21 Volt was registered at my multimeter but when I checked on the output side of the small coil it was only 1.4 volt-see the two photos below:
When i took it out and checked on the coil resistance and it was very high and because of the high resistance of the coil the DC voltage had dropped to a lower value.
I took the coil from a junk board and fixed it and the display immediately came back-see the photo below:
Conclusion- This means that without proper DC supply voltage to the system IC, the TV acted abnormal with no picture, no sound and blue screen symptom. I hope after you have read this article, you will know where to check for the problem in the TV if you ever came across such problems.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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https://jestineyong.com/how-to-repair-display-problem-in-canca-tv/
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Parasuraman
September 11, 2017 at 9:29 pm
I bow in front of your skill to quickly get to the root of the cause and take remedial action. The information provided is new to me.
Suranga Electronics
September 11, 2017 at 10:51 pm
Thanks Mr.parasuraman ,
erik blankers
September 11, 2017 at 11:43 pm
Hi Suranga,
Nice and quickly repair, but what caused the damaging of that coil??
Robert Calk
September 12, 2017 at 12:05 pm
Good job, Suranga. Thanks for the article.
Yogesh Panchal
September 12, 2017 at 1:23 pm
Good Repair! Suranga
Albert
September 12, 2017 at 8:46 pm
Good pro job Suranga! Just in case anyone needs to know what the inductor value was, look up the color chart value here:
https://www.elexp.com/res_cap_color-chart.aspx
mahmoud_tajpour
September 13, 2017 at 2:35 am
Suranga well done good and nice epair.
jeovanny viteri
September 13, 2017 at 9:34 pm
MR SURANGA
What do you mean by SYSTEM IC DO YOU REFER TO THE MICRO CONTROLER OF THE TV
PLEASE REPLY ME BECUASE I HAVE SUCH A PROBLEM I MY TV
THANK YOU JEOVANNY
nangoli ronald
September 15, 2017 at 6:57 am
Thanks for this article,got such faulty tv but i could not troubleshoot it bt now i hv got it.though i have computer moniter old model,it had fault of taking to display but only shows standby light for one hour before displaying but try crosschecking with circuit board and nothing found dead mostly in power section so please what could be problem because clients is complaining.i will be grateful if u spot for mi fault pls.
Ulises aguilar pazzani
September 21, 2017 at 12:37 pm
Mr Suranga , great fix
Ulises Aguilar
April 8, 2018 at 12:04 pm
Mr Suranga grate Job Sir
Boris lukukula
May 14, 2018 at 6:28 am
your work is very commendable! I appreciate your every effort in this venture. many thanks for your useful ideas