Hı,
İ have a problem on 11ak19pro chasis.
Q603 (buk444) has over heating. İ can not touch to heat sink. So i can not operate crt. Besides picture is narrow both sides.
Could you please help me. What can i do?
Baho
Comments
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Hi!
Check and re-solder E-W correction circuit parts. Check and clear the horizontal coil connector pins.
One of many tips:
The east west fet Q603 BUK444-200A was short and R629 2.7ohms fusible was open, replacing both cured the problem. 2 Values for this component: 2.7 ohm in 90 degree crt's ... 27ohm in 100 degree crt's. 32" models value is 56 ohm @ 1 watt safety
Repair tips:
https://english.electronica-pt.com/repair-tips?ref=11AK19&marca=&sintoma=
2
Hı zsoca33,
Thank you very much your advices. İ cleaned e/w and horizantal cicuits.i resoldered horizantal and e/w circuits. İ changed e/w driver Q603( 9NQ20T) and R629(2.7ohm) also i changed c620,c621,c610,c611,c613,c626,d611,d612. But Q603 is still over heating and picture is narrow on screen.Q605(BU508) heating is normal. Not over heating. But Q603 heating is too much.
what can i do anything?
0
HI
C614, replacement, ,,maybe C630
L602 may be burned
0
Hı tvdoktor,
c614 is absent. İt is empty on board.i already changed c630 by new one. But problem continue. By the way i checked L602 is 0.5ohm. L604 is 3.5ohm. L602 is Cook but L604 has over heating. İs it probably defected?
0
Hello
What is the name, type of TV Bush or what?
I may look at different drawings
Remove the Q603 and turn on the TV and measure the FET control electrode with an oscilloscope./ IC401 45 pin/
Without a transistor, the picture will be concave.
If L604 is heated then Q603 or C621 / 1U100V / short -circuit or drives ohmically
The C626 C 613 is important to be good. Do not drive ohmically
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Hı tvdoktor
my chasis is 11ak19pro (Vestel Black LK 70/110 degree )
I already changed Q603(9NQ20T) ,c621(1uF100v),c663(1nF 1kV) and R629(2R7).
but problem is continue. I'm suspecting for L604 . May be failed.
By the way when ı was checking tv on working,it is failed. Tv is not working now.
There is a sound like cik cik. I think horizontal driver BU508D is failed.
I have not an oscilloscope at home. So, ı can not check IC401 15 pin. I can measure with avometer. But firstly ı must solve cik cik sound.
0
Hello
Flyback transistor became dead because the size of the picture is large, or you caused you.
1
Hi
There are 2 problems now. At fisrt you need to solve the horizontal drive fault.
1. Remove R629 (2R7) it paralyzes the EW correction, the picture will pillow-effect.
2. Remove Q605 (BU508D or BU2508D)
3. Put a 40-60 W tungsten filament bulb between Q605 collector and emitter on the board to loading the psu.
4. Start the tv, the bulb will half-lighting.
5. Measure B+ voltage (it need 150V at 110° CRT by the schematics) You can adjusting the B+ voltage by VR801. C829 and C606 changing recommended.
If VR801 not builted in the B+ voltage calculating method: B+ = 2.5 x R823 (kOhm) / R824 (kOhm). -> 2.5 x 130K / 2.2K = 147,7V
The L604 may burt inside. Can you change it another one? Roll off the wire from coil. Maybe becomes visible the burnt wire.
PS: This chassis is a very old type. Check the PCB wireing looking for hairline split. ( sometimes it's invisible!)
1
Hı zsoca33,
i made your advices. İ took out Q605 and put a bulb on collector and emitter contacts. When i open TV by remote control bulb is lighting one second and turn off again. İ think there is a short circuit somewhere.
By the way i took out L604 and rolled off wire from coil. İ did not see any burnt on the wire.
İ heard on another forum that L604 coil is 15 microhenry. İ looked it to purchase it but i did not find anywhere.
So ı'm thinking roll on the wire on coil again. İ will use same coil.i hope it will not problem.
Finally the problem is continue
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Hi Baho!
Change C630 at same value (electrical voltage value may higher). Do not measure, change! During operation it may leaking.
If R629 was burnt, check R606, L604 also. L604 may opened.
(If one of C610, C611 leaking or dead, it kills the Q605. C611 value depending on CRT type, changing only same value.)
1
Hı zsoca33,
i made your advices. İ changed R629(2.7ohm) ,c610(100nf/250v) and c611(6.2nf/1600v). Also i changed D611 and D612.
İ checked L602 coil is 0.5 ohm it is cool.
L604 coil is 3.5 ohm but this coil has over heating. İ can not touch this coil also Q603 is over heating.
Today i opened TV and after worked 5 minutes TV failed. Now ı'm hearing cik cik sound like a bird. İ think horizantal transistör Q605 or ew transistor Q603 is burnt. İ will check it.
0