Hope someone can give me an easy answer to this: just replaced all the face lights (incandescent) on this unit, plugged it in and everything worked as it was supposed for a few hours. Turned it off, went to bed. Next morning turned it back on, it lit up just as nicely as it did the night before. After a couple of hours, went into the kitchen for some coffee, came back, no lights. Bulbs are good. Looks like the 8v supply for the bulbs is gone, but I don't find any obvious problem as to why. Everything else is working. ???
lights out, (literally) on qx-8000
- Thread starter jhan
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- 8000 pioneer qx qx-8000
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VintageDutch
Active Member
Hello @jhan
Welcome to audiokarma... please write an introduction for yourself in the appropriate section https://audiokarma.org/forums/index.php?forums/introductions.145/
Yes probably there is an "easy fix"
The Bulbs have a separate supply winding and fuse (3amp) (markt yellow) of the transformer...
Looks like the fuses died....
Welcome to audiokarma... please write an introduction for yourself in the appropriate section https://audiokarma.org/forums/index.php?forums/introductions.145/
Yes probably there is an "easy fix"
The Bulbs have a separate supply winding and fuse (3amp) (markt yellow) of the transformer...
Looks like the fuses died....
Many many thanks, VintageDutch. Several years back when I acquired the 8000, I took advantage of Pioneer's offer of free schematics, but no fuse is shown in the 8v line on the unit connection diagram copy sent me (it would appear that fuse was overlooked when the diagram I have was drawn but added in on your copy). The 2A speaker fuses and the 1.5A main power fuse are readily found and I hi-lited them. However, the components list does have the 3A as well as the 2A speaker fuses and the 1.5V main fuse, and I have been wondering where and why the 3A listing.
Your help is very much appreciated.
Your help is very much appreciated.
VintageDutch
Active Member
8 x 300 ma 2.4 A + 150MA of function bulbs... Yeah you need 3A
Now it is your job to find it in the amp..
Now it is your job to find it in the amp..
The good news is that I had decided not to put it back into the case and put the knobs on and just let it simmer for a bit. If/when I find the light fuse I'll post a photo. I gather from your comment that it is likely buried deep.
I actually have 2 8000's - one has QUADRA PHONIC in the center of the 4 speaker lamps; the other (and I suspect newer), has the number 4 there, and that is the one in which the fuse (hopefully, and not the transformer coil) blew.
An aside note from something I read on a previous AK 8000 thread: deoxing the main/pre switch restored power to a weak channel. Doubt I would ever have thought on my own to do that.
I actually have 2 8000's - one has QUADRA PHONIC in the center of the 4 speaker lamps; the other (and I suspect newer), has the number 4 there, and that is the one in which the fuse (hopefully, and not the transformer coil) blew.
An aside note from something I read on a previous AK 8000 thread: deoxing the main/pre switch restored power to a weak channel. Doubt I would ever have thought on my own to do that.
made in china
Active Member
Heads up on replacement incans: I have occasionally found them to pull way more power than what you thought you bought.
I like to test any new incans I acquired on my bench power supply, as it will show me the true power draw of the bulb.
I think some vendors have a difficult time convincing lamp manufacturers to properly make 8V bulbs.
I bought some 8V 50mA axial bulbs, and they actually pulled 150mA....weirdly, they weren't even much brighter than an old 50mA bulb in side-by-side comparison. Hotter and hungrier.
I like to test any new incans I acquired on my bench power supply, as it will show me the true power draw of the bulb.
I think some vendors have a difficult time convincing lamp manufacturers to properly make 8V bulbs.
I bought some 8V 50mA axial bulbs, and they actually pulled 150mA....weirdly, they weren't even much brighter than an old 50mA bulb in side-by-side comparison. Hotter and hungrier.
Good to know, made in china. Thanks. I hadn't checked the draw on the bulbs, and it has crossed my mind that the fuse gave up from something more than old age. Haven't yet discovered, however, where Pioneer might have hidden it.
The ebay seller says each bulb is individually tested before it's sent out; his fb is 100%/17153, so I took for granted the bulbs are in spec.
The ebay seller says each bulb is individually tested before it's sent out; his fb is 100%/17153, so I took for granted the bulbs are in spec.
VintageDutch
Active Member
i'm not going to break a bubble.... but UK. US and EU manufacturiers impose better quality builds and checks, and buy only A quality from "the same factory' but with there own brands stamped on it...
sometimes even only producing end caps and buying elsewhere the "glow in the dark" and getting the stamp Build in EU, UK, US etc.... really guy's the world is a strange place...
Same thing happens with cars..... Volvo builds a chassis for Polarstar vehicles... and buy's engines from Renault...just rebranding them...andthat is just 1brand... there are way more....
and often.. what is left tends to be sold of as B quality in big online shops... and even there is a big difference to find..
sometimes even only producing end caps and buying elsewhere the "glow in the dark" and getting the stamp Build in EU, UK, US etc.... really guy's the world is a strange place...
Same thing happens with cars..... Volvo builds a chassis for Polarstar vehicles... and buy's engines from Renault...just rebranding them...andthat is just 1brand... there are way more....
and often.. what is left tends to be sold of as B quality in big online shops... and even there is a big difference to find..
jhan. Go to the transformer and find the Blue wires. Start from the transformer and hand trace them out. One of them will have the fuse connected to it (probably in a clear plastic sleeve). Or it may be on a board. By it's age, I'd surmise it's probably in a clear plastic sleeve.
Hi, larryderouin. There are 2 blue wires coming out of the transformer - one going directly to a 2A fuse right out in plain sight, which I have found to be the main power fuse. 
The other blue wire runs to a connection on the on/off switch for the front speakers. I have physically located the channel fuses as shown on the schematic, but I have yet to find the light fuse that is shown on the schematic posted by VintageDutch, which isn't shown on my apparently earlier schematic I am beginning to wonder if this unit came wired with a fuse in the light circuit.
The other blue wire runs to a connection on the on/off switch for the front speakers. I have physically located the channel fuses as shown on the schematic, but I have yet to find the light fuse that is shown on the schematic posted by VintageDutch, which isn't shown on my apparently earlier schematic I am beginning to wonder if this unit came wired with a fuse in the light circuit.
Then best to start at the lights and backtrack the wiring to the source. Do both wires noting color or color and trace color (Blue with white stripe...for example), and where they terminate. You may have to open up wiring bundles to do this. Also when you have both ends of the wire, do a continuity test on each wire to ensure no breaks in the wiring. The Solid Core wire loves to break internally if it's manhandled too much. So go easy on it.
Thanks again, Larry, but just the possibility/likelihood of my breaking a wire somewhere makes me less than eager about jumping in and pulling boards out to see what might be under them or where a certain wire connects. The unit is plays spectacularly as it is, at least to my ears, except for AM, and I'm not wild about creating more serious problems trying to solve a much lesser one.