Uniden bearcat UBC 360clt no sound output
Hi I have inherited the above desktop scanner, all seems to work correctly but there is no sound output. The only sound I do get from the speaker is the beep confirmation when you press a key. No output from the headphone socket either. Not even radio static with squelch fully turned down, tried a reset by holding 2, 9, and hold buttons but still no sound, does anyone have any experience with these scanners, thanks.
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Open it up and post some high resolution straight shot pictures of the board(s) and add it using the attachment function.
In the mean time you can read this:
https://www.badcaps.net/forum/troubl...o-audio-repairLast edited by CapLeaker; 05-15-2024, 06:42 PM. -
by the sounds of it it must have an RX problem, since you can hear beeps.Comment
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Yes could well be RX problem as won't grab any frequency, not even a strong local radio station, just keeps on scanning, the beep however is crystal clear..
I have uploaded some photos as asked, maybe you can point in the right direction.Comment
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What are you using for an antenna? the telescpoing one that comes with it?Comment
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Measure the resistance between the centre pin of the BNC connector (antenna) to the outside shield. Try using a AM loop antenna to receive something on the AM broadcast band. See what that does. On the first picture is all your RF and audio stuff. The 450khz receiver (AM/FM demodulator) is the JRC2552 IC next to the metal can. I wonder if it is just a certain band not working or if everything is dead. If everything is dead things aren't looking good unless you got a donor or spare parts (besides if you measure a short on the antenna).
I do have a BC340CLT here that I just fixed. On this one was a cap bad. On your picture it would have been the cap that is black. But I doubt it.Comment
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Here is a schematic for a UBC355CLT. Close enough for the RF path's anyway...Comment
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The black cap next to the heatsink with a KIA78/R09PI strapped to it. Some kind of voltage regulator. What was the fault you had to warrant replacing this cap? Looks like a 100uf 25v.
also what do these 2 pots do. RT2 and RT3
No short across antenna reading 1.4 Meg ohmsComment
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The caps around the 9V regulator are always a problem on the older scanners with long run times,
O.k. So you have no short on the antenna, good! Did you check the other bands? This step is important look at the schematic. The receiver has 5 bands! Each band is tuned for a specific frequency range.
So do you have a problem with the switching in between bands, a blown IF amps, PLL unlock, a mixer missing or that RX IC bad? Don’t just screw around with pots that you don’t know what they do, because then you probably need an alignment and you need specific tools to do so.Comment
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Result it was the squelch pot.. reading 8Meg ohm in both directions, so I swapped over too the other pin.. I'm receiving the world now...only my squelch operates in the opposite direction. Thanks for all you help anyway.Comment
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That's a rare one. Never encountered that on a Uniden scanner. Never the less a good fix!
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Good morning everyone,
I'm trying to repair an onkyo ht-r390 that has no sound output, despite the volume being at maximum, the rest seems to work; the video output signal (coming from an hdmi input) is present, but the audio is absent. Similar situation if I send an audio signal from any input I have no output.
The firmware reported is the following:
M:1.00/11107BLP
D:?.??/????????
O:1.00/11107AL
The DSP firmware given the question marks seems corrupt.
On the BCHDM-0678 - 25140678 - QPWBCHDM0678A0 board the chip that usually seems...05-11-2025, 02:59 AM -
Hi all, I've started this new thread in order to avoid further polution of thread "Yamaha RX-A3010 working, no sound output"
Just to recap:
No sound through Audio and AV analogue inputs, only sound when 2ch stereo or pure direct is activated (so no sound when I e.g. choose 7ch of Hall in Munich etc.). Hoever when I connect HDMI I've sound in all options (movie, music, eyc.) First suspicion was the DSP chip/PCB so I bought a scrap 1030 with a good functioning PCB (in this one a driver stage was defective (PRT DC: 67), after I swapped the PCB I've performed a factory... -
I found an old Bearcat 300 scanner that had no display, but the audio and squelch worked, over at my workplace. This unit has a lot of hours on it. It had some capacitor replacements and other mods done to it too before I found it. To troubleshoot this problem, the usual is to check the +25v and -30V and replace C98 on the main board. That should fix it. There is also a case of a shorted button board (just unplug that ribbon cable and the display should work again). Spoiler alert!
Was not the case on this one.
My display didn't work, because I had a missing -10V on the display... -
The off/on/auto switch was busted so i forced it into auto mode and now the blue light comes on but i don’t get any audio output. Does anyone one have any experience repairing this amplifier? I looked it over, checked some the of output transistors, some of the power resistors and cleaned that nasty conductive epoxy glue stuff off but not having much luck in the trouble shooting department.
I did however find a part of the PCB that was discolored from heat...03-22-2024, 06:00 PM -
Dear reader
I have been asked to check out a faulty Bose Wave system belonging to a relative. The faulty unit produces loud intermittent pops and crackles. Sometimes there is speaker audio output (FM/AM, CD etc.), most of the time there isn't. This behaviour degraded over time fairly quickly, to the current situation where no sound is put out at all. Gently messing and wiggling wires, connectors or heatsink has no effect in force-replicating the problem. I have little experience in audio repair when it comes to (main)board electronic component faults. Bose repair WAS about 140$ (most...
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