Aiwa MX-X3300M Amp/DSP problem

[Dom]

Hi - me again

I posted a couple of days ago with this problem and it was suggested I
checked the VFD soldering - done that and its all good. I still have the
same problem though - the Amp turns on and there is no display. After 15
minutes or so the display fades in slowly and if I quickly cycle the power
to the amp the controls appear to work again for a while. The same happens
with the radio VFD when connected (external Aiwa unit).

I've tested the VFD voltage from the regulator and when it is working I get
around 30 volts which appears within spec. When the display is dead I get
around 1.6 volts. This leads me to think that maybe the regulator for the
VFD has a problem.

Euras appears to have a fix for the problem but I dont have access to it
(symptoms are exactly the same - locked up control panel until the display
gets going as well).

Any ideas or schematics ? The VFD regulator circuit looks like it might have
got a little warm at some point but without schematics etc I'm a little
stuck (I'm a digital electronics engineer with limited analogue knowledge).

Thanks all again

Dom

 

[JVC Dude]

Its usually the electrolytics in that supply circuit that go dry. The Tr
does tend to run hot and discolour the board- usually without problem.

AW

 

[Dom]

Cheers TR - much appreciated

I'll have a probe around next time I've got some space on the workbench.

Is it just the ones in the VFD circuit I need to worry about or is this
problem more widespread across the board ?

Thanks again

Dom