Reforma de bandeja 3CD’s con IC LA6568 equipo AIWA NSX-SZ300
Hoy me llegó un equipo AIWA modelo NSX-SZ300 con bandeja de 3CD’s el cual tenía problemas para cargar y cambiar los discos. Cambié las dos gomas que comúnmente usa este modelo de bandeja, sin embargo siguió presentando problemas tanto para abrir y cerrar la bandeja como para cambiar los discos por lo que decidí hacer una modificación que permita que los dos motores encargados de dichos procesos reciban un voltaje ligeramente más alto, pudiendo operar así más eficientemente.
Esta bandeja de 3CD’s usa el integrado LA6568. Se cambiaron dos resistencias de 3,9k, una de ellas de montaje superficial, colocadas en los pines 14 y 15 de dicho IC por dos resistencias de 4,7k. Estas resistencias van conectadas por uno de sus extremos a tierra y forman parte de un circuito divisor que entrega un voltaje de referencia para el motor que hace girar a la bandeja de discos.
Además de esto, se retiraron dos resistencias de 20k conectadas a los pines 17 y 18 del integrado LA6568, ambas de montaje superficial y cuya función es similar a la de las dos anteriormente mencionadas pero para el motor que abre y cierra la bandeja. Ambas resistencias van conectadas por uno de sus extremos a tierra y al eliminarlas aumenta el voltaje de referencia del motor mencionado.
Ya con estas reformas el equipo trabajó como uno nuevo, sin problemas.
Tengo en el taller un tv marca MTEK modelo MTV14NF, buena imagen pero sin sonido, creo que la falla es
en los item pero no tengo los valores si me pudieran ayudar con esta falla les quedaria muy agradecido el IC
de la jungla es 8873CSBNG6KJ7.
Hello Isaac!
Thank you very much for the info!
I checked the link for the motor problem but although the manual shows that there is a resistance of 10K between pins 2 and 8 on the actual board there is no resistance R3 for 10 k only one R1 of 3.3K. should I place a resistance of 10 k between 2 and 8 and a parallel one of 15k ? Sorry for troubling you but if you have some time and you know something I will be grateful to you!
Thank you very much!
Regards, the resistance used to adjust the reference voltage must be placed between pins 2 and 9 (not 8) of the TA7291, reduce the value of this resistance makes the engine speed increases and vice versa. The mentioned resistance may be SMD or may not, in any case if you have doubts you can find the datasheet of the TA7291 to find out which is the Vref pin.
Besides, I forgotten to mention before that the belts that move the tray to rotate and open or close must be replaced with original ones, because a shorter or more rigid may cause mechanism malfunction.
Hello Isaac!
I checked the mechanism and it seems ok. I have to tell you that the original mechanism of the system was ksm2131BAM which is not available for sale now. I bought the ksm2131FAM which uses the 4zg-1 tray mechanism instead of the 4zg1a. It may be this the problem so I plan to change the sled motor of the original ksm2131BAM because when I install it is like dead. However when I first installed the KSM2131FAM it was able to play the cd once after trying several times.
Do you happen to know how the gears (blue and black syncronize? maybe it is a problem with the syncronization. I searched everywhere but there was no definite answer on how the synchronize. The blue gear has an arrow that should point to a small circle on the tray assy, but I am not sure if it is coreeclty syncronized with the black gear before I insert the tray back in.
Thank you very much!
There are three possible causes that can do the tray open and close erratically: the first is that the open / close sensor is not working properly, as I said you, the second possible cause is that the mechanism is not well synchronized.The third and final possible cause is that the motor isn’t strong enough to move the mechanism. I hope the information will be useful for you, Luck.
Hello!
I have an Aiwa cx nv800 system that has problems reading the cds. In the beginning the disc would not spin. I changed the whole optical mechanism. The problem persisted. The tray would not close when it should and even when pressing the power button the tray would open.I changed the belt under the tray for rotating the tray but then the tray would not respond to close or open or rotate.
Could you help me please?
It is posible you didn’t armed correctly the mechanism, or it could be than the open/closed sensor is not working properly, for this reason the microprocessor does not know if the tray is open or closed and works erratically.