I have a Tecnics Su V620, It produces no sound. However, the front board works I have confirmed this by using it in another similar spec amplifier so i'm A little stumped on the no sound. I've checked for faulty solder joints and there appears to be none and the voltages seem to be correct accross the board. Any one have any ideas on a fix for this?

I also have a Technics Su v500 mk2 that is stuck on Phono and the machine just turns on regardless of the power button?

 

On the '620: The unit may be in protection mode. With the power on, measure the voltage (to ground) at either end of R609 and R610. Should be in the mV range.

 

Hi there again, what do I do if they are in the mV range, does that mean it is in protection mode if so how would I get it out?

 

In the mV range is good. Do you hear a click 3-5 seconds after you turn it on? Trying to determine if the speaker relay is pulling in.

 

It doesn't seem to unfortunately, I have two fronts to it and one of them just loops though and doesn't go any further but does click in. And the other is stuck on phono, the one on phono seems to be faulty

 

That unit uses RSN power modules, not the most reliable of hybrid amplifiers. I had some errands to run this aftenoon, but I'll try to give you some more troubleshooting steps when I can.

 

Thanks that's great, I look forward to your help!

 

Before proceeding, tell me again exactly what the symtoms are. With the 'good' front board on the unit, does it power up at all? Can you select input modes and/or tune to different frequencies? Any error messages? In other words, does it seem to work OK except there is no audio output?

 

With the good front, the amp will power on and sit in a boot loop with it clicking the relays on then straight off. I have been told it could be an issue with power getting to them. But it just keeps clicking through. No inputs can be selected only the ones that had been used before

 

When you first plug it in, does it immediately go into that loop, or do you need to push the on button for it to start?

Interesting that there are fuses on the low rail rectifiers, but not on the high rail rectifiers. Pull fuses F3 and F4 and give it a try - see if it stops power cycling.

 

**Dukeerz Friend Here**

The SU-V620 goes into the clicking relay loop once the standby button has been pressed and it is as it is trying to start up. No buttons need to be pressed, it goes straight into the loop.

On The SU-500 M2 with the bad front, it just sits on the phono input whether the amp is turned on or not.

 

Start a second thread for the SU-500 M2, keeps things from getting too confusing.

I assume you *Do not* have the V620 powered through a DBT, it is plugged directly in. Pull those fuses and try powering up. See what happens.