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July 2010 Repair Newsletter
By Jestine Yong on July 6, 2010
If you are a first time visitor to my blog and wish to read the July 2010 repair newsletter about “Interview With A Professional Electronic Repairer” then you can click HERE to subscribe to my monthly repair newsletter and you could also read all the previous repair newsletter too. See you in the other side!
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Shamshul
July 6, 2010 at 12:01 pm
tv panasonic model tc2933(sophia) - problem . power, picture and sound all ok but screen dark. try to adjust screen at flyback but still not enough. setting at brigthness and contrast already full but still dark (gelap) where need to check.
admin
July 6, 2010 at 10:00 pm
HI Shamsul,
If there is a good heater and g2 voltage then suspect a bad tube.
Jestine
Shamshul
July 7, 2010 at 2:23 am
How to know a good or bad tube? can i replace it with china tv 29 inc tube?
admin
July 7, 2010 at 8:09 am
HI Shamsul,
You may need a crt rejuvenator to test it or if all the signals/voltages are tested good at the CRT board then suspect a bad tube. You may replace it with another tube but make sure the part number is the same. otherwise it can blow the HOT and other parts.
Jestine
Shamshul
July 15, 2010 at 10:46 pm
Problem tv no power, saya dah check voltage kat kaki transformer scondary, 1 kaki sepatutnya voltage keluar around 130v direct to flyback
but just only 30 to 40v. adakah transformer rosak??.
Shamshul
July 15, 2010 at 10:57 pm
may i know where need to trace signal for picture???. what i know RGB is for colour signal. problem tv screen in blue screen but just only sound can hear but no picture.
admin
July 16, 2010 at 8:16 am
HI Shamsul,
You may need to isolate the problem by following this link:
http://www.scribd.com/doc/2957819/TT204-Identifying-television-SMPS-problems
jestine
admin
July 16, 2010 at 8:24 am
HI Shamsul,
You may need to check the video IF ic to see if there is any signal output.
Jestine
Shamshul
July 20, 2010 at 12:15 pm
TV Daewoo, problem just VHF channel got picture but not for UHF channel. already re-find channel but still not found... maybe tuner box spoilt. can i resolder back tuner box???
admin
July 21, 2010 at 9:02 am
HI Shamsul,
Have not seen this problem before but the tuner is the biggest suspect. Tuner components except the legs are rarely have dry joints problem. Anyway, you can try it out.
Jestine
Shamshul
July 22, 2010 at 10:55 am
may i know. Flyback ada related tak dengan problem 1 horizontal line melintang (tiada bukaan vertical)?????
admin
July 22, 2010 at 7:40 pm
HI Shamsul,
Biasanya tiada kaitan tetapi sekiranya supply voltage of vertical IC datang dari flyback maka ia ada kaitan.
Jestine
Shamshul
July 24, 2010 at 3:17 am
Problem colour tv bertompok tompok, separuh hijau dan separuh lagi merah... kat mana nak check..?
admin
July 25, 2010 at 5:17 am
HI Shamsul,
Tompok seperti itu ada kemungkinan masalah di posistor ataupun dry joint kat vertical output ic.
Jestine
Shahidan
July 26, 2010 at 6:54 am
I just came across your website. A very informative site.
Shamshul
August 1, 2010 at 3:20 am
CRT TV Sharp model 29H-S20M, problem no power. what i know latest tv sharp have a protection circuit. got relay in power supply section (primary). question - how can i find the protection circuit?. from where need to trace?.
admin
August 2, 2010 at 5:35 am
Hi Shamsul,
Since i do not have this circuit thus i do not know if this model have any protection in the primary side or not. Not all tv must use relay in protection circuit,some may use optoisolator circuit.
Jestine
Shamshul
August 2, 2010 at 9:35 pm
Can i give you the youtube link so you can see it any problem that i will upload at youtube. may be more clearly when you see compare to write in paper.
admin
August 3, 2010 at 9:13 am
Hi Shamsul,
Yes you can.
Jestine
Shamshul
August 3, 2010 at 9:00 pm
i got the problem with zener diode, location at primary SMPS. already check and confirm zener diode already short. the problem is i don't know the voltage bcoz no part number at the body. body is red but only 1 blue stripes at katod side. can help me???
admin
August 4, 2010 at 8:20 am
Hi Shamsul,
Try check other section to see if you can find the similar zener diode or not. You may need a zener diode tester to find out the voltage. Or the blue line could indicate it is a 6 volt or 6.1 volt zener diode.
Jestine
Shamshul
August 5, 2010 at 10:26 am
Need TV schematic. model SHARP 29H-S20M or others 29inc sharp model. if you got any link or website...pls help me. thanks
Shamshul
August 6, 2010 at 4:02 am
TV SHARP - When turn on power, set goes to stand by mode.red led on. try to push channel button and remote control button nothing happen. where need to check??? pening - pening lain model lain problem dia..
admin
August 6, 2010 at 4:37 am
Hi Shamsul,
Sorry i do not carry any schematic.
Jestine
admin
August 6, 2010 at 4:47 am
HI Shamsul,
Is the main power supply have any output voltages? if zero volt then you may need to trace if there is supply to the main power supply power IC. Check to if the optoisolator or the relay have any signal coming from the cpu or not because a bad CPU can cause standby problem.
Jestine
Shamshul
August 6, 2010 at 6:11 pm
1) Already check power supply section at 2ndary transformer after diode, 20v (Ecap 25v 2200uf) output direct to sound ic - ok. 10v (Ecap 16v 1000uf) output direct to feedback ic photecoupler - ok. what i found now is just only 10v (suppose to 130v) output direct to fly back and HOT transistor.
2) May i know what is function PR57 ?
admin
August 9, 2010 at 7:16 am
Hi Shamsul,
You may need to trace the B+ line or even isolate it because a shorted HOT, Flyback or even shorted horizontal yoke coil could cause the supply to become low.
Jestine
Shahidan
August 24, 2010 at 5:28 pm
I have a small sub-woofer amplifier which uses a TDA2030 IC. The power supply smoothing capacitor tend to heat up very fast and became useless as soon as the volume was turned up. At first I suspected the capacitor was faulty. I replaced the capacitor three times and had the same problem over and over. I suspected the ic had shorted.
Need your expert opinion.
admin
August 24, 2010 at 7:35 pm
HI Shahidan,
I suggest that you check the capacitor surrounding area and directly replace the ic and retest. Make sure also the voltage across the cap is not too near to the working voltage of the cap otherwise the cap may have problem.
Jestine
Shamshul
September 20, 2010 at 5:20 am
TV AKIRA, Problem went turn on power, just red led on .when i push the channel button nothing happen but i wait for 30 to 40 second push the channel button again tv on as normal.when off the power for 10 minutes i need to repeat again. where need to check?
admin
September 21, 2010 at 1:40 am
HI Shamsul,
Is all the output voltages from the SMPS good and stable?
Jestine
Shamshul
September 23, 2010 at 4:12 pm
TV AKIRA, Problem no sound, what i found is capacitor 25v/2200uf blow. replace it and turn on power the cap become hot quickly . when i check the voltage is 25 to 30v supply from secondary transformer section after diode,it should be around 16 to 20v. my question is
Ada kah component bhgian primary mempengaruhi output voltage di bahagian secondary transformer atau transformer rosak.???
admin
September 23, 2010 at 8:47 pm
HI Shamsul,
Does this tv use optoisolator ic? If yes then one of the components in this feedback circuitry may have problem. Otherwise you need to check on the primary side.
Jestine
Shamshul
September 24, 2010 at 8:30 pm
No ! this tv not use optoisolator ic.
admin
September 24, 2010 at 10:21 pm
HI Shamsul,
Then i suggest that you check all components in the primary side. It could be one of the component that have problem increased the duty cycle causing the output to increase.
Jestine
Shamshul
September 26, 2010 at 11:26 pm
Already check all component at primary side, all - OK. now just suspect transformer spoilt at 25v side, what i know not easy to find the replacement for transformer . can i modified 25v drop to 16v??? how???
admin
September 27, 2010 at 4:37 am
HI Shamsul,
Sorry no idea on this.
Jestine
Shamshul
September 27, 2010 at 8:59 pm
TV Brand GC (Gemilang cekal)problem on power screen shown paddle lock (gambar kunci mangga) try to push any button at tv and remote control but nothing happen. maybe need lock code but??????
admin
September 28, 2010 at 3:03 am
HI Shamsul,
Sorry i do not have the unlock code. Try check the cpu or the eeprom IC to see if the supply voltage is good nor not.
Jestine
Shamshul
September 28, 2010 at 12:49 pm
TV AKIRA - after check at B+ voltage after transformer cap 160v/100uf got 200v. it suppose to 130v. now what i found both supply got high voltage. already check component at primary side and changed new ecap still fail. my question have a flyback related ??? maybe can generate voltage ??? pening - pening
admin
September 29, 2010 at 3:51 am
Hi Shamsul,
Try check component in the optoisolator circuit. It could be a resistor that had gone high ohm.
Jestine
Shamshul
November 9, 2010 at 10:44 am
What i know Sharp tv got the protection circuit. if audio section or others part got problem, set will turn to standby mode when power on. so i don't know where the problem. any idea how to confirm ???
admin
November 10, 2010 at 9:25 am
HI Shamsul,
What is the complaint of the sharp tv?
Jestine
Ben LeMire
July 15, 2011 at 11:40 pm
I have a CRT tester / rejuvenator for sale if any one needs it.
Make me an offer
Contact Ben LeMire
In Salem Oregon at
lemire123@netzero.net or call 503 999 1304