Got a Yamaha soundbar and found it won’t power on? It’s likely to be the “capacitor plague” and Yamaha won’t help you. Read on for a step-by-step guide on how to fix it yourself.

Background

I’d owned a Yamaha HTY-750 for a few years before the trouble started. It began with the unit refusing to power on — switching off at the wall and then back on again before hitting the power switch helped for a while. Then it got progressively more and more difficult to get it to come on at all — even with that “trick”. Finally, it gave up completely.

It was well out of warranty, and I did not want to be faced with the cost of shipping the heavy unit back to Yamaha for what I suspected would be a costly repair.

Turning to the internet, there was absolutely no support or information on this problem for this Yamaha HTY-750 soundbar model. But I did find a repair manual online and opened the unit up to see if there was anything obvious like a blown internal fuse.

Seriously, these things are built like tanks. You are not going to get into this by undoing 4 screws let me tell you! I forget now, if I actually managed to get to the power board to see the fuse, I suspect I got frustrated by the solid construction and dozens of screws. I wasted an hour as I recall, before giving up and confining the unit to the loft in disgust.

I looked around online for a replacement, but this unit was discontinued. In fact the Yamaha soundbar line had changed dramatically and there was a whole new selection available. However I wanted the “older” sort with the dozens of micro-speakers providing the “sound beam” technology and the auto-setup for your room dimensions using a microphone.

Eventually I found a used YSP-900 on eBay which came with a Yamaha subwoofer. It cost £189, which was a lot of money, but a lot less than you’d pay for a new one, especially as it came with the seperate sub.

I bought and paid for the YSP-900 and fetched it from the seller. It all worked fine for several months. However after less than 6 months the unit started to behave the same as my old bar!

Not again!

Once again, the power off at the wall trick worked for a while, until once again I had another broken unit on my hands — and worse still, no sound for watching movies at home on my projector.

Help is at hand

This time when it came to searching for help, I was in luck. There was a long and detailed thread over at AVForums where many people with many different models of Yamaha soundbar all had the same problem. Better yet, someone had posted about a solution! Note that although the AVForums thread is about the YSP-1000, the symptoms are the same and the YSP-900 (and other models) are all mentioned in the thread.

The problem, in almost all cases detailed in the thread was a degraded capacitor in the power supply. This was apparently down to “capacitor plague”-(TLDR; mass-use by electronics giants of sub-standard capacitors).

The capacitor is in position “C515" on the power board and is actually labelled pretty clearly, so if you can get to the board in the first place, you’re not going to find it hard to spot the offending component.

Fixing a YSP-900 & HTY-750

Note — before I start, let me say that I am not an expert of any sort when it comes to electronics, I am nothing more than a tinkerer. My first approach when it comes to dealing with something that is broken is to dismantle it. Sometimes I can see a problem, other times I can’t and re-assemble and give up. What I’m trying to say is that if you are brave enough to attempt this repair (and if you have a broken unit, you have nothing to lose) and are able to solder a couple of wires together, you can do this repair.

I have repaired both my YSP-900 and the HTY-750 using the same replacement component and the same approach. While the steps to disassemble are different, the power boards are largely the same and the C515 capacitor is easy to find, remove and replace.

I detail below the steps I took to repair the HTY-750 and hopefully this might help you resurrect a broken unit too.

Tools:

Soldering iron & solder

De-soldering pump

Electric screwdriver and Philips cross-head bit (for the 40+ screws you’ll need to remove)

Normal screwdrivers

Sharpie markers (for marking components/connectors)

Warning!!

You are about to attempt a fix on an electrical device, take all the necessary precautions before you start, including unplugging the unit from the power and discharging the power supply of any latent charge.

I accept no responsibility for any accidents that may occur, or indeed for any further damage you may do to your device.

This is an easy fix, but you need to take care and be responsible.

Start

Start with the unit upside down…you’re faced with a LOT of screws here!

Before dissassembly

Remove bottom cover

Unscrew ALL screws on the bottom of the unit — yes, every single one! Even the ones on the silver surround at the front of the unit.

After removing the screws, the bottom should lift off, revealing:

Bottom cover removed

Check out how many screws you end up with!

Rather a lot of screws!

Unplug wires from board and remove metal plate

Unplug all the wires from the circuit board that is revealed when the bottom is removed. Take care with the 2 connectors that are identical (both have a black and blue wire)— I opted to colour both the connector and the socket with a Sharpie to make sure they went back in the same place:

I used a red and blue Sharpie to mark the connectors and corresponding sockeets

With the connectors all undone, unscrew the screws that hold the metal plate with the circuit board attached to it and remove the metal plate with the circuit board still attached (there’s no need to take the circuit board off the metal plate!).

In the picture below the whole metal plate shown highlighted in red is what you are removing:

With the metal plate removed you should be able to see down to where the power board is located deep in the soundbar:

All connectors unplugged…

Unscrew the silver screws that hold the power board in place and unplug all connectors from the power board so that you can remove it.

Take extreme care with the connector highlighted in the picture below — it bridges the power board to the board to the left. You should gently lift the connector free on the left side — i.e. unplug it from the board to the left and leave it attached to the power board.

There are a couple of very stubborn connectors that I literally could not get to come undone, both are beige-coloured and are pushed firmly down onto the board. See below for an example of one of the connectors:

There are 2 beige-coloured connectors that I could not remove…take care with these

I decided not to force them (or my luck!) as there was enough play in the cables to allow me to lift the power board out and find what I was looking for: the C515 capacitor!

Capacitor is labelled for us

At least Yamaha labelled the offending capacitor for us, eh?!

De-solder capacitor C515

Flip the power board over and find the 2 legs of the C515 capacitor — again it’s labelled! I’ve highlighted it below for you:

I made sure my soldering iron was hot and held it to each of the legs in turn, when I saw the solder melt, I used a de-soldering pump from Maplin here in the UK — part number N40CH — to suck up the molten solder.

With the solder removed, the capacitor pulled out easily.

Prepare the replacement capacitor

I am sure if you had patience to wait, you could order the exact same capacitor from RS components but I am not a patient person and also, I didn’t want to risk the Christmas post.

So instead I got these massive replacement capacitors from Maplin. They are seriously over-specced for the job, and physically a lot bigger than the capacitor you just removed, but I can say they do indeed work. The part number is N38CN and it costs 99p at the time of writing.

The legs on the capacitor are too short and too far apart to fit into the holes used by C515, so you will need to solder on some extension wire:

Extend the legs of the capacitor

After attaching the extension wire (they where bread-board jumper wires, but any single strand wire should do), I insulated the exposed legs using insulation tape. I wanted to use heatshrink tubing, but had none at hand.

“Tin” the ends of the extension wire ready to go into the board (i.e. melt a thin layer of solder onto the leg ends).

Solder the new capacitor into place

Trim the extra wire you added and bend it in to make it fit the holes on the board where C515 used to sit.

Poke the ends of the wire through the board and use your hot soldering iron to melt a blob of solder onto the ends:

Solder the ends of the new capacitor into place

Make sure the new capacitor is firmly held in place, if your soldered joints are not firm, try again!

Here’s what it looks like from the other side, you can clearly see how large the new component is. Note the way I had to bend the extended legs in to fit the original holes:

This thing is HUGE!

So, you’re basically done now! What you’ve done is replace this little failed capacitor:

The offending capacitor

With a new replacement you paid 99p for!

Reassemble and test

Reassembly is the reverse of disassembly — I’ve always wanted to write that ever since first reading it in a Haynes car manual as a teenager.

Carefully replace the power board, screw it into place and re-attach the connectors. Remember to attach that bridge connector that joined from the power board to the board to the left.

Replace the metal plate with the other circuit board on it and re-attach all connectors. Remember to observe the markings you made to show which of the blue/black connectors went where.

There’s no need to put the case on to test it, just don’t poke your fingers inside while the power is on!

Plug in and try the power button on the front. The soundbar should click into life, just like new!

Now replace the bottom of the unit.

You’re done…

Note to Yamaha

Yamaha, I am very disappointed in you as a company over this issue. You have to be aware of the problem as it is well documented around the net and you must have received a large number of soundbars back for repair.

I attempted to contact Yamaha UK and enquire about a good-will repair out of warranty but was met with no response.

There is clearly no acceptance of blame here by Yamaha and unlike Samsung who, no more than a couple of years ago, replaced blown power supply capacitors in out-of-warranty TV’s free of charge (see story here), Yamaha are not doing the same.

I was and am pleased with the performance of the Yamaha soundbars I have purchased, but definitely not happy with the way Yamaha have handled this issue.

References

AVforums thread

Capacitor plague

Maplins replacement capacitor

Maplins de-soldering pump

HTY-750 Service manual

Samsung out-of-warranty repair story