Service manual audison vrx series

[RonBenRas]

Hello guys.

i guess this would be helpful for somebody than me..

 

[motronix]

Which Model of the VRX do you need? and/or what section

 

[Leolabs]

Which Model of the VRX do you need? and/or what section

Hi,do you have the VRX6 420.1 schematic,esp the power supply section?I have a unit that producing some low level high pitch noise through each channel.Also I measure the dc-dc mosfet gate section is working at around 100kHz,is that the correct PWM frequency?

Thanks in advance!

 

[motronix]

At the PWM module TPC3 R39 need to be 18K and C18 need to be 1NF.

 

[motronix]

Correction R39= 12K (it depend what version)

 

[Leolabs]

Both R39(12k) and C18(1nF) measure ok with them stripe off from the board.

Funny thing is the PWM frequency remain around 36kHz for U11 output and 30kHz for U12 output,which is way beyond from the calculation,which should be around 110kHz.

Broken SG2525?

 

[motronix]

The osc. freq. is OK this is PUSH/PULL topology.
2X36Khz = 72Khz. if it will be 110Khz then you have problem

 

[Leolabs]

The osc. freq. is OK this is PUSH/PULL topology.
2X36Khz = 72Khz. if it will be 110Khz then you have problem

Hi,the DC-DC converter is fine as per u said.

I notice that out of 6 LD1.2 module,only 1 is not making any noise,while the other 5 are generating some noise around 4kHz,which u can hear them with speaker connected even no input signal at all.

Could it be the module issue?Do you have the pinout diagram of it?