Aiwa NSX 999

[Jazzer]

This unit is perfectly operational except for LCD panel completely out.
All other controls are lit except volume knob led. Would appreciate any
advice. Have circuit schematic but no repair manual.
Thanks, Jazzer.

 

[Arfa Daily]

This unit is perfectly operational except for LCD panel completely out.
All other controls are lit except volume knob led. Would appreciate any
advice. Have circuit schematic but no repair manual.
Thanks, Jazzer.

Is it definitely an LCD, not a VFD ? Most Aiwas use VFDs. Several common
problems for no display are bad joints on the VFD heater pins ( these are
the 'paired' pins at either end of the display ), an open circuit picofuse
in the heater supply ( usually located on the Front PCB, above and to the
right of the display from the back ), and open circuit caps in the voltage
multiplier for the -30v supply ( usually located at the left side of the
main board, around half way up ). Does the vol knob actually have a LED in
it ? I've seen a lot of these Aiwas that have a red insert in the knob, that
looks like it should light up, but is actually nothing more than an inert
pointer.

If it really is an LCD, try shining a strong light on it from the front, and
see if you can see any activity. If you can, then the backlighting has
failed, which shouldn't be difficult to figure, if you have schematics for
it. I have full service manuals for just about every Aiwa ever made, except
that one, it would seem ...
so can't be any more specific. Sorry

Arfa

 

[Jazzer]

Is it definitely an LCD, not a VFD ? Most Aiwas use VFDs. Several common
problems for no display are bad joints on the VFD heater pins ( these are
the 'paired' pins at either end of the display ), an open circuit picofuse
in the heater supply ( usually located on the Front PCB, above and to the
right of the display from the back ), and open circuit caps in the voltage
multiplier for the -30v supply ( usually located at the left side of the
main board, around half way up ). Does the vol knob actually have a LED in
it ? I've seen a lot of these Aiwas that have a red insert in the knob, that
looks like it should light up, but is actually nothing more than an inert
pointer.

If it really is an LCD, try shining a strong light on it from the front, and
see if you can see any activity. If you can, then the backlighting has
failed, which shouldn't be difficult to figure, if you have schematics for
it. I have full service manuals for just about every Aiwa ever made, except
that one, it would seem ...
so can't be any more specific. Sorry

Arfa

Thanks very much Arfa (love that program here in NZ) - Your reply is
just what I need to set me on track. I was wrong on display
description, it is most assuredly VFD. The volume indicater is lit, so
OK there. Will tomorrow check the areas indicated by yourself and check
the -30v supply. Far too cold here to venture outside to my workshop
this evening. Many thanks Arfa, will let you know what I find. Cheers,
Jazzer.

 

[Mark D. Zacharias]

This unit is perfectly operational except for LCD panel completely
out. All other controls are lit except volume knob led. Would
appreciate any advice. Have circuit schematic but no repair manual.
Thanks, Jazzer.

Bad power supply caps, in a voltage doubler circuit near the rear of the
unit on the main board. Don't remember the value exactly - they're not very
large. Maybe 10uF to 47uF.

Mark Z.