TECHNICS SU-V50 I have no current drive in my Technics SU-V50. The part i need is an Audio Output IC No. SV14004A

That sounds suspiciously like an issue with speaker connections rather than amp output!

There are manuals and specs here including a Service Manual

https://www.google.com/search?q=technics+su-x840+user+manual

..

https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Technics..

Hi Greg, I sent you the link so you can download the circuit of your Technics su-z780
I hope it helps you
Greetings Franco Dosil

Hola Greg, te envio el link para que puedas descargar el circuito de tu Technics su-z780
Espero te sirva
Saludos Franco Dosil
https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Technics-SUZ-780-Schematics.pdf
Elektrotanya for electronics experts

If these are model numbers,you would need the part number of the IC. If the IC is specific to Technics, it is most likely to be unavailable. If you would like more information, or would like to inquire about a repair, please visit my website at audioserviceclinic.com. You may contact me there. Thank you.

HI,
The out put ic number of Technics SU Z2 is SVITK2038. If you can sent your email address the i will sent the schematic diagram
OK

Check for dry solder joints especially on the main power output transistor.
A blown power transistor will stop the 'Current Drive' from engaging so if the problem you have is intermittent then it is most likely dry solder joints.

Hope this helps.

NAother option is to fix a universal amplifier kit into the set which powers from the same voltage preferrably a MOSFET drive which are very much available in the market and can be suited into the set. They will alos be very effficient but take care tto do the fixing mechanically , connecct the right power and groung with good shielding. Disconnect the old amp totally and use the power lines that come to the IC. I hope this works for you. Good day

Usually this is a defect in the output amp IC. If you have no experience with repairs of these types of units, have it checked by a service shop. If the output AMP IChas failed, it will cost about $75 for a replacement. This unit uses an RSN3306P IC .

Dan

If I understand your posting correctly, the amp works using the Aux In connectors but not using the VCR1 even when VCR1 is selected correct? If that is the case, there is an internal electronic switching IC (TA9263 I think) that may be defective. This is not a complex repair and can be confirmed easily by any shop that does audio repair. They will trace the incoming signal with an oscilloscope to the IC and see nothing come out when VCR1 is selected. The IC costs less than $10.

Dan