Pioneer VSX-3300 - relay clicks but no display or output

[getthedog!]

I've got a VSX-3300 which turns on (volume knob lights, relay clicks) but that's it.

• Fuses are all OK
• I'm seeing 5v and 2v in places
• Power button functions OK
• 12v rail appears dead - checked at the test points and other plug pins
• Relay on the small transformer board clicks and stays engaged, but the relay on the amp board isn't clicking at all
• Not seeing any voltage coming out of the main (big) transformer (tested the PCB)
• The only signs of life are the relay clicking and the volume knob lighting up. No display and no fader LEDs

Any pointers? I can't figure out where to trace the 12v rail to. I assumed it would originate from the big transformer which connects to the main board? Cheers!

Service manual is here: VSX-3300 Service Manual

 

[getthedog!]

Great news! It's alive although I don't know why

I had it sitting upside down for a while today to check the underside. Anyways hours later I decided it was time to give up and put it on the "too hard" shelf. I gave it one more try and couldn't believe my eyes - it was working perfectly

Anyways I told my partner afterwards and she laughed, apparently our toddler had been in the room and was hitting the bottom of the amp

So there must be some crook connection somewhere

 

[getthedog!]

Ugh I moved it to its new home in the shed but the problem has shown up again I'll have to get my toddler to whack it again

Before it died (again), I took some measurements/notes for reference

• When amp is plugged into power, but in standby mode, there will be no voltage from the DC side of the main transformer

Here's how a VSX-3300 normally starts up:

1. Power button is pressed
2. The relay on the small transformer board clicks, volume knob and fader LEDs light up, -18v shows up at both ends of the DC side of the transformer
3. Display turns on about half a second later
4. A second or two later, the amplifier relay clicks and the system is ready

 

[getthedog!]

OK I think I can claim victory at last

I re-flowed all the solder joints on the small transformer board and so far so good!

 

[getthedog!]

I also fixed the display which was temperamental - again, it was cold solder joints. Fun times

 

[jayohee]

@getthedog! I liked your explanation on the repair of your VSX3300. I have the exact same problem (nb: mine was unused for a while and I recently tried to use it. Display issue was previously an intermittent issue, but receiver still worked. Now apart from the "Click" and the volume dial lighting up, nothing works.) I will try your suggestion of re-flowing the solder joints on the small transformer board. However, whilst I have the same problem with the display, I am unsure as to which connections to look out for and possibly redo. An explanation or pic would held greatly. Thanks in advance.