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Last edited by CapLeaker; 05-18-2018, 05:06 AM. -
Re: Pioneer QX-949 in protect mode / no audio
gray ELNA caps.Comment
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Re: Pioneer QX-949 in protect mode / no audio
I've got my digikey shipment yesterday and ordered a bunch of different transistors. Turns out to be a good thing I did that.
The transistor to replace: 2SA726
I've ordered KSA1015GTRA (higher gain ones) and KSA992FTA. Turns out, that the KSA1015GTRA don't have the gain that the 2SA726's had. However the KSA992FTA's are bang on. I am going to try a matched pair of KSA922FTA first.Comment
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Re: Pioneer QX-949 in protect mode / no audio
Good news. The KSA992FTA did the trick and the amp is working A1! A little side note: Those KSA992FTA have to be installed backwards. The pin out is the other way around compared to the 2SA726.Comment
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Re: Pioneer QX-949 in protect mode / no audio
easier than having them crossed leggedComment
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Re: Pioneer QX-949 in protect mode / no audio
Did an alignment on the FM tuner on that thing aaand? I broke the friggin slug in the discriminator (that large metal can). Here is an easy fix for that. Take a screwdriver with a magnet attached and gently break up the old slug and fish the debris out from the can, turn the unit upside down and blow the hole out with a can of air.
This is important: Note that the IF of the tuner is 10.7Mhz. So you need a slug from a different receiver or transceiver with an IF of 10.7Mhz. In my case I used the slug out of a vintage junked Motorola Mitrek VHF transceiver. There are 2 slugs in that transceiver that are a perfect replacements for the tuner. No shimming, cutting etc required.
Last edited by CapLeaker; 10-19-2018, 08:12 PM.Comment
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Re: Pioneer QX-949 in protect mode / no audio
There are some batches of the small TO-92 case transistors in 1970's era audio gear that develop intermittent and sometimes persistent failures after 40 years. Intermittent crackling, popping, and hissing noise is frequently a symptom.
If you identify one such small transistor that failed then it would be wise to search every PC board for other transistors of the same part number and physical appearance.
With electrolytics in 40+ year old audio gear it is a good idea to measure both capacitance and ESR for all of them. Small capacitors may fail more often than big ones because the tiny caps contain only 1 or 2 drops of electrolyte. When it dries up the capacitor become an open circuit.
EBComment
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Re: Pioneer QX-949 in protect mode / no audio
capacitors are cheap enough and easier to replace with new even if old ones test good . flaky transistors can be found with freeze spray and heat .. some transistors on the hit list depend on the case style whether it might be likely to fail or not ..Comment
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The Problem: This player has a toggle switch to select between Stereo, Mono R, and Mono L. Regardless of the setting it outputs the sound to both the L&R audio jacks. In the Mono R position, the audio output level is normal (from both the L and R audio output jacks), in the Stereo position the audio output is about half the volume, and in Mono L, it's about 3/4 the volume. Something about putting it into Stereo mode is causing the volume to drop significantly and I can't figure it out.
The player processes the audio signal using two different reference frequencies. The "R"... -
I have an older Pioneer receiver (VSX-44) that's been dropping the HDMI output (black screen) for a few seconds every few minutes. Setup is HTPC -> Pioneer DVD HCMI in -> Pioneer HDMI out -> Samsung TV HDMI in, all with cheap HDMI cables that have never caused trouble before..
I initially found a lot of play in the receiver's HDMI inputs and output so I kind of squeezed them back into shape and they're making a tighter connection, but the problem persists.
And also, often, the HDMI will drop out in exactly the same way (black screen) just as my central air... -
Hello team,
I've got a new issue with a Denon Avr-2700H.
After several minutes working, receiver stops playing sound with a poc eared in the speakers.
Receiver still work and display video with error message on display.
Seems to me that is the main output relay.
I'm looking for the service manual that I can't find for the moment.
Does somebody have it?
Regards... -
This post is specific to the Pioneer SP-SB23W, also known as the "Andrew Jones Edition" soundbar. Andrew Jones being well known in the audiophile engineering industry for superb audio designs. My reason for stating this is if you are looking for an inexpensive 2.1 channel TV soundbar, this one rivals many 5.1 systems -- and without littering a room with speakers (sub-woofer is wireless, can be hidden anywhere). As a 9 year old device, they should be pretty cheap on the used market -- perhaps dirt cheap if no audio-out.
Bought mine off of Craigslist cheap.
So here's the... -
When I select the FM receiver, I find a radio station, the sound is heard on REC OUT(L,R), REC TAPE1(L,R),REC TAPE2(L,R) on high-ohm headphones, the sound regulation does not work.
The output reacts when I connect the record player to PRE OUT FRONT L, the sound is heard in the speaker but the sound regulation does not work. Then it does not matter what I chose on the front selector.
I replaced the capacitor C303/0.047F, nothing changes.
I'm asking for help, what should I do next?
Thanks in advance!...08-05-2025, 10:23 PM
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