Saturday, March 28, 2015

FAULT FINDING TIPS SONY KV32XBR45

SONY KV32XBR45

FAULT FINDING TIPS 

1. CONVERGENCE
SYMPTOM : KV32XBR45 convergence is way off in the horizontal direction
CURE : Unit has an open R789 a 18 meg 1/2 watt resistor for the Horizontal static convergence. The tech will have to make a resistor out of 3, 6.2 meg resistors.
2. CONVERGENCE
SYMPTOM: KV32XBR45 Unit has convergence of all vertical lines are displace horizontally. Tech replaced the CRT without authorization. This did not solve the symptom
 CURE: Suggest tech look for R789 and see if it is open It is on the on "C" board. It The value is around 10 meg. There are two different chassis and CRTs used for this model. If they have the older chassis type that requires H stat convergence (CRT board has H stat control) they need to order the older CRT as per the manual. If newer type (No H stat) then the new CRT as per Service Manual supplement -1 is needed. CRT 8-733-743-05 The H Stat is done using the Yoke ring magnets. I have attached the two Service Manual supplements, and the SB325R1.
3. CONVERGENCE
SYMPTOM: KV32XBR45 Unit has sever Horizontal static convergence error. TV cae to us from another shop where the CRT and flyback was replaced. Customer call us for secont opinion.
 CURE: Suggest tech look for R789 and see if it is open It is on the on "C" board. It The value is around 10 meg. There are two different chassis and CRTs used for this model. If they have the older chassis type that requires H stat convergence (CRT board has H stat control) I have attached the two Service Manual supplements, and the SB325R1. However none of them have show this resistor. We were able to install a resistor in this unit that was a two 10 megs in series. Trimming the value by adding another 10 meg in parallel with one of the other 10 megs. we were able to converge the set. Original part was not available.
4. CONVERGENCE
SYMPTOM: Unit has mis-convergence of red and blue vertical lines. They are displace horizontally. Tech replaced the CRT without correcting the symptom.
 CURE: R789 open H-state not operational. What I'm finding is a resistor that appears to be open on this "C" board It is R789 The value cannot be read nor is it listed in the ESI software parts list. Trying another value from 10 to 20 megohms. This resistor is in the ground return of the H-stat resistor that is installed in the CRT. Tech needs to try different values to try and make this set converge horizontally. This TV converged with a 10 megohm resistor.
5. CONVERGENCE
SYMPTOM: Unit has nis-convergence of red & blue vertical lines which are displaced horizontally. Tech replaced the CRT. This did not solve the problem.
 CURE: Suggest tech look for R789 and see if it is open It is on the on "C" board. The value is around 10 meg. There are two different chassis and CRTs used for this model. If they have the older chassis type that requires H stat convergence (CRT board has H stat control) they need to order the older CRT as per the manual. If newer type (No H stat) then the new CRT as per Service Manual supplement -1 is needed. CRT 8- 733-743-05 The H Stat is done using the Yoke ring magnets.
6.DEAD
SYMPTOM: Unit was dead. has shorted horizontal output and shorted Q601, & Q602 components in power supply replaced. After replacement unit will turn on but still has no secondary voltage output of power transformer. All relays click but no high voltage. Has sound.
 CURE: Tech needs to check the condition or RY602. RY602 is the switching relay that turn on and off the set. The relay is "HOT" switched. In other words one side of the relay is connected to power oscillator output that runs nearly 350 vac Peak to Peak at 90Khz. Once the relay is closed this energy is placed across the power output transformer and provides the drive necessary to produce the B+.Measuring the input voltage of the relay to "HOT' ground found it to be 150 volts DC mode. But on the other side of relay we has 3 volts DC mode. Unit has defective RY602 relay.
7 .GEOMETRY
SYMPTOM : Unit is trying to constantly adjust the vertical height and horizontal size intermittently.
CURE : When monitoring the E/W Pin output of the M board the signal was very instable. It was decided to replace IC351 the Jungle IC. This corrected the trouble.
8 . WEAK VIDEO
SYMPTOM : Sony KV32XBR45 Unit has a very faint picture But the OSD is fine. Problem shows up in the tuner and video input mode. Tech ordered Q401 but did not correct the symptom

CURE : There is video at the base of Q401 but not at the emitter. Q401 measures 9 volts on all elements. Base must be 4.5 volts. Transistor is in cut off. Bases and emitter are the same 9 volts. Unit has open R617 a 680 ohm resistor.