Comments on: Track Leak Under SMD Resistor Found In SHARP CRT TV MODEL 21FX300

By: sang heon BAIK

sang heon BAIK — Mon, 20 May 2024 12:04:49 +0000

It seems that You have top-notch skill for repairing CRT TV.I'm really impressed.

By the way I have LG CRT TV and its model number is CN-29H3
And I already have posted on reddit as to repair this CRT TV
https://www.reddit.com/r/ElectronicsRepair/comments/1cb7m6y/how_can_i_check_str_6707_regulator/

Although I replaced all of bad capacitor and replaced STR-S6707 regulator But It seems that It cannot repair symptom of no display.
When I connected CRT TV to AC power strip and switched on, I measured voltage of pin #9 of STR-S6707(6.2-6.4 DCV). I found that DCV(placing red probe to cathode terminal of diode) of ZD808 was 6.8-7V and D805 and positive pin of C811 was 6.4-6.6V , D807 and positive pin of C812 was 13-13.2V, But D806 was 0.5-0.7V. It is doubt whether D806 is faulty diode or not.
Below link is my drawing of clumsy schematic which contains STR-S6707 and surrounding components.
https://i.ibb.co/9Z8649w/scan0001.jpg

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By: Yogesh Panchal

Yogesh Panchal — Sun, 05 Feb 2023 10:29:16 +0000

Good Job!Sir,

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By: Parasuraman S

Parasuraman S — Sat, 28 Jan 2023 16:43:25 +0000

In reply to Albert van Bemmelen.

Many thanks for your comments, very valuable tips and guidance!

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By: Parasuraman S

Parasuraman S — Sat, 28 Jan 2023 16:41:24 +0000

In reply to Waleed Rishmawi.

Many thanks for your comments and encouragement, dear friend!

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By: Parasuraman S

Parasuraman S — Sat, 28 Jan 2023 08:54:59 +0000

In reply to LEE.

Many thanks for your expert comments and opinions!

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By: Albert van Bemmelen

Albert van Bemmelen — Sat, 28 Jan 2023 07:42:06 +0000

A uncommon timeconsuming and costly repair although with very interesting article as result! Never heard of a jungle ic before! But Google explained it as follows:
A jungle chip, or jungle IC, is an integrated circuit (IC or "chip") found in most analog televisions of the 1990s. It takes a composite video signal from the radio frequency receiver electronics and turns it into separate RGB outputs that can be sent to the cathode ray tube to produce a display.
About the not always trusted Ring tester results while testing any transformer, I also short the secundary coil and watch the primary coil output change of the leds on my Ring tester. If they do not change accordingly I know the transformer is bad. Caused by an open or internally shorted secundary coil. Which with a TV STB transformer obviously is harder to check because of its many coil connections.

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By: Waleed Rishmawi

Waleed Rishmawi — Sat, 28 Jan 2023 06:44:06 +0000

I bet you enjoyed replacing all these capacitors..LOL. of course as always you go over and beyond the call of duty to fix and repair things. keep up the good work my friend and thanks for sharing even with such an old device that is not worth fixing. have a blessed day.

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By: LEE

LEE — Sat, 28 Jan 2023 06:14:10 +0000

AS usual you go above and beyond what is necessary to fix these old clunkers.
One can only hope you got rewarded handsomely for this repair.
I don't think any one is in Australia would attempt a repair like this anymore.
Especially when you can pickup flat panel TV's at yard sales for $20 here in Aus.
The only people interested in tube TV's are Arcade buffs as the reuse the tubes in their Arcade machines.

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