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
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.
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.
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