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Replaced Pioneer SX-990 pointer light but have a quick question

John Burdett

John Burdett

New Member
Just replaced bulbs including the pointer but the lamp's been dead since I've owned the receiver and it looks like someone had the old one wired up incorrectly (pos to the phono bulb, which doesn't seem right or useful)

So my question for any of you that own or are familiar with the SX-990 is: When SHOULD the pointer light illuminate?

-When either FM mode is selected? (pos wired to fm bulb)
-Just when a stereo station is tuned? (pos wire to STEREO indicator. this is how my SX-2500 is wired although I didn't do it and someone may have changed it)
-Both FM and AM? (I guess could pull pos off the signal gauge lamp but doesn't seem like that was the original wiring

I'm GUESSING it was originally wired off the FM indicator lamp and only illuminates when in FM auto or FM mono? And when someone fiddled with it in the past they accidentally connected it to the phono and didn't realize it didn't work, or just gave up? Just seems like kind of a snub to the AM listeners out there if it only works on FM. And then I realized my SX-2500 pointer only lights when a stereo station is tuned. So I'm really wondering which one is "correct."

I can't thank you forum posters enough for all the information at my fingertips. This is my first post here, although this forum has been super helpful just by searching. Didn't find the answer to this specific question, thanks in advance if anyone can lend a hand!
 
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Thanks John that makes sense. I guess I'll find somewhere in the signal gauge circuit to pull power from.

Found something else that is kind of fishy. I never use AM but was messing around and the FM STEREO indicator flickers/lights up a lot as I move the dial. I don't think this bulb should have any power at all in AM mode. Seems like there's some real weird stuff going on, how foolish to think I was just going to replace some lamps. If this sounds familiar to anyone or know off the top of your head why this would be happening let me know. Looks like I'll have to get into the schematic and figure it out.

Thanks again!
 
Correction: the FM Stereo indicator was illuminating JUST SLIGHTLY in all modes. Still functioned and lit when FM station tuned but there is just enough juice to make the LED flicker a tiny amount any time the receiver is on. Wasn't enough to light the original bulb at all. I went with the quick and easy solution and put the old bulb back in. :D

Got the dial pointer working too, thanks for the help!
 
as you have led's as i do it takes very little current to illuminate them.the fm portion UNLIKE later pioneers is switched on in fm ONLY. i very well could be wrong but i'd try and and clean the mode switch. could be theres enough junk on it to illuminate the led.i wouldnt be surprised if an incandescent stays off.just a thought mind you.in fact its wise to clean them all AGAIN even if done before. i went around with that several years ago on a 1500td (virtually the same in this respect) but i cant remember the details,i do remember i used a larger led in the stereo indicator location.its the WHY ive forgotten, but some of it was the stereo indicator wasnt very bright but there was something else.i also re-transistored the indicator board that drives that light. i wish i could recall the details. it works now and plays very well. but i went round and round on that thing for a couple of years on several details.i remade the meter bracket lamp holder to accept fuse leds too.
 
another thought.is that light actually illuminating? i mean do you have the cover off and actually see the stereo light actually on and not reflected light from somewhere else.
 
That pointer bulb in the 990 and 1500TD is perhaps the most time consuming procedure in the entire unit. Kudos to you for tackling it. Not a simple procedure.
 
john stumpf said:
another thought.is that light actually illuminating? i mean do you have the cover off and actually see the stereo light actually on and not reflected light from somewhere else.
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John - Yes, its actually illuminating, but juuuuuust barely. Very light flickering. I had the top off to swap all the bulbs to LED and to be honest when the cover is on it is soooo faint and flickery it would have taken me a while to see it if I hadn't noticed when the top was off. I swapped it back to the incandescent bulb and it does NOT draw enough power to illuminate. I haven't gotten time to clean that selector switch like you suggested yet, but it makes perfect sense to me that it could be the problem. Frankly I was trying to decide what to do with this lil receiver and I'm leaning towards doing a full recap and restore when I get some time. I need the experience and it seems like a decent one to dive into. After some more soldering practice I think I'll be ready to give it a new lease on life!

gbroot said:
That pointer bulb in the 990 and 1500TD is perhaps the most time consuming procedure in the entire unit. Kudos to you for tackling it. Not a simple procedure.
Click to expand...

gbroot you aren't kidding! What a hassle, but always nice to complete a puzzle and get all the pieces back where they go. Question: My pointer seems fairly dim, does that seem right? It was burned out when I got it so I have no reference. I would assume the LED would be a decent brightness but it isn't really. Original pointer on my SX-2500 was definitely brighter. I'm wondering if I got the led positioned incorrectly in the little rubber holder.
 
in regard to the pointer,mine has an led,it works but its not very bright.the trouble in this case is that leds are directional.they radiate from the end not very much sideways
 
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