Standby Problem In CRT TV Repaired
My customer complaint to me that his Sharp CRT TV does not have display and I found that the standby light was red color. I have even tried to press on the remote control On button with same symptom. I concluded that this TV have standby issue causing no high voltage symptom and the result was no display.
The moment I opened the TV cover I was shocked to see there was a burnt gekco on the mainboard-see the photo below:
After removal of the mainboard, there were actually two dead burnt gekco.
Taken out the two dead gekcos and after cleaning the circuit board, I saw the horizontal driver transistor was actually shorted by the gekco’s body fluid.
Once this transistor is shorted, the horizontal driver transformer would not be energized.
I replaced with another good working transistor and then powered it On and the picture came back to life again-see the photo below:
I was curious how these two gekcos could enter into the TV and found that actually there was a small hole at the side of the TV in which I missed out when opening the cover. I sealed the cover and considered the job done.
Conclusion- Just imagine if there were no gekco in the TV and the TV symptom was no high voltage (no display) so where do you check the mainboard? The area that you need to check is the horizontal oscillator circuit area.
If there is no pulse from the horizontal oscillator IC, horizontal driver transistor and horizontal driver transformer open circuit or dry joints in this circuit, it can cause no high voltage symptom. If there is no B+ voltage to the flyback or the flyback itself have problem, it can also cause no high voltage symptom. So take note on this.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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Albert van Bemmelen
December 4, 2021 at 1:20 am
I guess that 2 gecko's could have made many more little gecko's? Luckily they didn't!
Gilberto Galindo
December 4, 2021 at 1:56 am
El mundo de la electrónica se ha vuelto tan, pero tan complejo, que bien te puedes encontrar fallas debidas a los propios componentes, a manos inexpertas ytayando de reparar por si mismas los aparatos o, como en este caso, gekos intentando reparar (o tal vez sabotear) los componentes.
Felicidades!!!!
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The world of electronics has become so, but so complex, that you may well find faults due to the components themselves, inexperienced hands and trying to repair the devices themselves or, as in this case, gekos trying to repair (or such time sabotage) the components.
Congratulations!!!!
Lynn Blakely
December 4, 2021 at 2:01 am
Suranga Thanks for the article. Very through in the proper way to find no turn on problem, and then further explaining several other ways to find different solutions for the same problem. That helps those that don't have the experience, and training that you have.8
Carlo Alberto Birocco
December 4, 2021 at 6:59 am
RIP gekco! What a strange death... killed by TV!
Abraham Getahun
December 4, 2021 at 7:53 am
Nice job! But would've been more clear repair, if you'd showed us the culprits. And I wonder what are the codes for the horizontal driver transistor, like I know HOTs have D2499, 1555...
Tayo
December 4, 2021 at 7:51 am
Im actually confused as i dont (didnt) think the flesh of a geico was conductive enough to short this component...
Parasuraman S
December 4, 2021 at 3:30 pm
Our booking agent (with world wide rights!) in suicide support once again! This time, probably a male and female would have contributed! Though cruel, we, technicians do get a lot of sets booked by these! Good job there, Suranga!
Mark
December 4, 2021 at 4:16 pm
Well done Suranga.
Waleed Rishmawi
December 6, 2021 at 2:58 pm
these creatures seek warmth in cold weather and they usually find their way in and cause these problems. i have encourntered countless of such issues and sometimes the damage is too big and expensive to repair. thanks for sharing and have a blessed day
Yogesh Panchal
December 7, 2021 at 4:18 pm
Good Job!Suranga
RJ
December 7, 2021 at 5:42 pm
A friend once gave me a computer back in the Windows XP days that no longer worked and when I opened the cover, it had the smell of death - not the death of the spider that got fried but the death of the board, electronics death. I'm sure everybody here has experienced that smell. I will never forget it.