If that primary is pulsing, a very good chance there is a short on the secondary of the PSU or there is a short on one of the other boards that is / are connected has a short. There are 2 power supplies, one for the sound bar with 23VDC and another one for the Sub with 34VDC.
Could be also there is something wrong with the feedback like the optocoupler, voltage reference or that zener.
First you got to find out if there is indeed a short on the PSU secondary or on the other boards connected to it.
Also look if the PFC is running on the primary of the PSU. No PFC = no high DC voltage output. Check the voltage on the main filter capacitor. If the PFC booster is working, you should see like 380VDC on the capacitor. What about the gate drive circuit?
The bridge rectifier isn’t the problem. Also check the primary of the transformer… maybe it is open?
The deep bass PSU is 34VDC. Makes me wonder if you are looking at the correct PSU?
Your vid shows the soundbar psu. So something isn’t right.
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JBL Soundbar 2.1 Deep Bass PSU No DC Power Output (Detailed, w/ Schematics)
I have two of these soundbars, both with the exact same issue. The soundbars were hit by lightning and no longer power on. The PSU does not output any voltage on the DC side. When plugged into mains, the DC output is a stone-cold 0.0 volts. The AC side of the PSU seems to be functioning correctly (as far as I can tell). When checking the plugged-in PSU with my thermal camera, the OB5269CP PWM controller (U1) and the two resistors (R12 and R13) pulse on and off. These run to the positive DC side of the bridge rectifier (among other components along the way).
There's no physical damage to the board or any of the components. I cannot for the life of me find any issues anywhere on the board. There are no shorts, no blown components/fuses, caps seem fine, resistors and diodes all seem to check out when testing with my multimeter.
What I've tried replacing (made no difference, so I reinstalled the originals):- Replacing the bridge rectifier
- Replacing the OB5269CP PWM controller
I've attached high-res photos, videos, and thermals of the PSU, along with an attachment of the boardview/schematics. If anyone could point me in the right direction, any and all help would be appreciated.
Full-Res Imgur Photos:
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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 -
I have bought this Zener Diode for this project what size and wattage resistor value do I need to use to get near 50 watt output
I bought this from an eBay seller but unfortunately they only had one
I bought three from Vetco Electronics these are Sylvania ECG5185A 9.1@10w A to Stud what size and watt resistor do I need to use to get near 10 watt output
I bought three of from them to also make battery packs with this output power limit in mind
I want to use this battery pack and turn it into a 9.1 output battery pack output to eliminate using 9 volt battery... -
Looks like I may need a little help from the PSU experts (or anyone really!
) I have a Corsair CX750M (Model 75-002019) that I picked up for free about 4 years ago. This is the PSU:
So here’s what’s strange about this one: it appears to work normally (normal output voltages) and any PC is stable with it. However, after a while (typically 10-20 minutes, but time can vary depending on the load), there is a sweetish smell of burned magnet wire insulation emanating from the PSU. Upon opening the PSU after this happened (many times), I was able to confirm... -
OK, this one dates back to 2015! I thought I had posted this, but realized I didn’t when I posted a picture of something else. So here it goes…
Back in 2015, I bought a pair of RCA WHP141 wireless headphones at Micro Center for $2. I even mentioned it in the best cheap/free scores thread right here. Just forgot to follow up with that.
As mentioned back then, these are (were) 900 MHz FM wireless headphones. No modern day Blutooth or anything like that. I knew they wouldn’t be great headphones or even that good… but the price was right!
So let’s take...
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It has been a long while since I posted here to ask anything....hope you can help.
I have this Samsung power supply that uses SPC1012T as driver for the PFC and it's giving me a problem that I can't narrow down though I've troubleshooted and fixed hundreds of boards similar circuits.
I am attaching a schematic from a different Samsung board, but the topography is very very similar if not 100% the same and it uses SPC1012T, which BTW is a pinout match to UCC28063 for which there's plenty of information. I haven't confirmed they are functional equivalents, but I strongly...
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