1. Failed Roku factory-built P/S (note chared components in bottom-right):


2. Replacement based on an LM317 regulator


3. DC Power Jack installed in the SoundBridge back panel


4. External Plug-pack

However I would suggest that ALL the electrolytics should be replaced.
Also upgrade the diode to a 3A 60V device.

I have to agree with you and especially after reading billd's problems after 12 months, I suspect I will be back into the psu within the next year. If that does happen, the external psu is looking like a better long term solution.

Having all of these good options from the forum is invaluable, especially where Roku support doesn't come through with a replacement.

Does anyone know if Maplin have a replacement power supply I could use ?

Anyone ?

Just a thank-you to the folks here for posting repair options. I finally got around to repairing my failed unit using an external PSU. I found the 12v 1amp PSU worked fine but I had to noticeably crank the volume compared to before the unit failed so I went with 15v 1amp instead. This seemed to be closer to the original volume level. I seem to recall before the unit failed that there was a very slight hum when not in standby and no music playing and it was there with the 12v and also with the 15v - just more so but not annoying. Could this be due to the amperage of these PSU's? Anybody else noticed this? I also noticed that it seems to be coming from the woofer - maybe its defective???

Iris

I hope that's not 15V only, you have a stepped down voltage for the digital circuit? Otherwise you'll probably be out a radio again soon.

Frank

FrankB wrote:

I hope that's not 15V only, you have a stepped down voltage for the digital circuit? Otherwise you'll probably be out a radio again soon.

Frank

No worries. Only 9.8v is been supplied on the second rail I just didn't go into that detail in my post.

Hello everybody !

I’m one more victim of the poor quality of the Soundbridge radio PSU.

I’ve read with a great interest this whole topic and I’ve already opened my Soudbridge and realized how burnt the previous capacitor was.

After some searches, I think I’ve found a PSU to replace the dead one and it may interest some other people : http://www1.conrad-uk.com/scripts/wgate/zcop_uk/~flN0YXRlPTMzNTIxNzg2ODY=?~template=PCAT_suchergebnis&p_searchstring=514292&p_back_template=&zhmmh_area_kz=62&sp_insert_kz=62&s_haupt_kategorie=&p_page_to_display=DirektSearch&p_load_area=$ROOT&p_artikelbilder_mode=&p_sortopt=&page=&p_catalog_max_results=20#

- Could somebody please confirm that the technical data is OK ? (output current : 1.7 A ; power 20.4 VA => 12 V DC)
- I also wonder whether it will fit in the Soundbridge ((W x H x D) 50 x 51 x 64 mm) ? (maybe it would be OK without the brackets ?)
- It seems to have only one output whereas I need 2 (one for the screen and one for the speakers) ?

Thank you for your answers !

Djeici

Djeici wrote:

... I think I’ve found a PSU to replace the dead one and it may interest some other people ...

You will need to repost with a searchable part number. The URL you provided points to a now defunct shopping cart.

Iris wrote:

...I seem to recall before the unit failed that there was a very slight hum when not in standby and no music playing and it was there with the 12v and also with the 15v - just more so but not annoying. Could this be due to the amperage of these PSU's? Anybody else noticed this? I also noticed that it seems to be coming from the woofer - maybe its defective???

Iris, my first external P/S build I got a strong hum. That was with a 12V transformer-based plug-pack. I swapped to a 13V switching-based plug-pack and the hum went away. It's now silent.
I never isolated the cause. I suspect the plug-pack was the cause - unusually it was specified for 50Hz supply only and I was running on a 60Hz supply. However it might have been the way I packed the recitfier circuit and cabling back into the speaker box (unlikely to be the cause as it's all DC) or due to not using a choke on the incoming 12V supply. The max current on the humming 12V supply was also only 1amp which is marginal.

Hello,

My first post here. I've read with interest the various PSU solutions. I'll post this first to make sure it's appearing in the correct forum, then I'll fill you in on my experiences with the R1000 PSU.

Ted

Okay, I'm having some trouble understanding the structure of the Roku forum, but I think my post is going to the correct group.

So, here's my story...

On the recommendation of a friend I purchased an R1000 in September. It's been working fine so far. My friend also bought the R1000 in September and it was not working correctly right out of the box. The issue was that it would display "rebuffering" often while the audio muted and the network connection was re-established.

He had NO luck at all with Roku "customer service". Fortunately, he purchased the R1000 on his American Express card and eventually got a full refund from AMEX after they couldn't get any response from Roku either.

After a couple of months I asked him if I could borrow his dead unit and try it at my house to see if the issue was that unit, or if there was a network issue. I brought it to my house and it exhibited the same problem, so it was an issue with this particular unit.

Thinking my R1000 would eventuall have the dreaded PSU problems describes so well here, I offered to buy the unit from him for parts. We settled on a price and I now own it.

BTW, I'm an electrical engineer with about 40 years experience working on professional electronic equipment.

Playing with the unit, I noticed the rebuffering issue was related to heat. When the unit was first turned on it would work fine for about 15 minutes, then start the rebuffering issue. I figured there was a heat issue.

Having nothing to lose, I opened up the unit and after some investigation of the PSU inside the subwoofer section, I had thought the issue was due to the copper wrapping shorting intermittenetly to the (what I now know) subwoofer LPF. It ran fine when it was taken apart. I put it together and the rebuffering issue returned.

I had noticed a bulge on the molex connector that connects the PSU to the main unit. There was a large piece of heat shrink tubing covering something that was very hot after about 15 minutes. I found that if I left the reassembled PSU/subwoofer off of the front unit that the device would work perfectly for days on non-stop operation.

Then I realized what was happening - the device under the heat shrink tubing was heating up the front unit (probably the 802.11b circuit) causing the rebuffering issue. I cut open the heat shrink tubing and found a 44 ohm power resistor wired between the 19 and 9.5v supply rails! It was dissipating about 2 watts and that trapped heat was overheating something in the main module near the metal box the connectors sat in when the unit was closed up.

Did Roku try to solve the issue with frying power supply components by strapping together the two power supplies with this resistor? Did they create another issue by trying to solve the poor PSU design with a "quick fix"?

Anyway, I'll now run my two R1000's until the PSU fails and then I'll probably go with the 15v external switched PS solution and series diodes to drop the 15v down towards 9.5v.

Ted

Hi Ted,
Welcome to the forums and yes, this is the right forum (SoundBridge Radio forum).

I have seen the resistor on the newer units. I have also seen the WiFi issue in older units w/o the resistor as well. I assume that the die in the WiFi IC is touchy on these units (the untis with rebuffer issues) with this issue and that the heat only exacerbates things. Seems even the VFD being on high can cause this. The whole PCB (well most of it) has a metal can (Faraday cadge) over the whole thing anyway. I have one that I had the PCB totally out of the unit and the can off and the VFD on low (so there was not heat source per se) and after a while the unit would rebuffed and if I shot “Cool-Offâ€

Hello Djeici,
Like the other person said, I think your link does not work. I think I measure about 1.5a of draw when on a 12v source. The 1.7amp should work, but I would use a 2 or 3amp just to make sure you are not running the wall wart to the max limits. But in reality, the 1.7amp one will work and might work for ever depending on how it's built (how good). So if you can get it for a good price or you don't have access to antoher one with a higher rating, then go for it.

Shoot me a PM if you want.
Regards, Matt

Djeici wrote:

Hello everybody !

I’m one more victim of the poor quality of the Soundbridge radio PSU.

I’ve read with a great interest this whole topic and I’ve already opened my Soudbridge and realized how burnt the previous capacitor was.

After some searches, I think I’ve found a PSU to replace the dead one and it may interest some other people : http://www1.conrad-uk.com/scripts/wgate/zcop_uk/~flN0YXRlPTMzNTIxNzg2ODY=?~template=PCAT_suchergebnis&p_searchstring=514292&p_back_template=&zhmmh_area_kz=62&sp_insert_kz=62&s_haupt_kategorie=&p_page_to_display=DirektSearch&p_load_area=$ROOT&p_artikelbilder_mode=&p_sortopt=&page=&p_catalog_max_results=20#

- Could somebody please confirm that the technical data is OK ? (output current : 1.7 A ; power 20.4 VA => 12 V DC)
- I also wonder whether it will fit in the Soundbridge ((W x H x D) 50 x 51 x 64 mm) ? (maybe it would be OK without the brackets ?)
- It seems to have only one output whereas I need 2 (one for the screen and one for the speakers) ?

Thank you for your answers !

Djeici

I think your right about the amperage issue casuing the noise since the unit can draw about 1.5amp when running on a 12v source. I know when I start to see a wall-wart fail on a M1001 I hear hum too.

billd wrote:

Iris wrote:

...I seem to recall before the unit failed that there was a very slight hum when not in standby and no music playing and it was there with the 12v and also with the 15v - just more so but not annoying. Could this be due to the amperage of these PSU's? Anybody else noticed this? I also noticed that it seems to be coming from the woofer - maybe its defective???

Iris, my first external P/S build I got a strong hum. That was with a 12V transformer-based plug-pack. I swapped to a 13V switching-based plug-pack and the hum went away. It's now silent.
I never isolated the cause. I suspect the plug-pack was the cause - unusually it was specified for 50Hz supply only and I was running on a 60Hz supply. However it might have been the way I packed the recitfier circuit and cabling back into the speaker box (unlikely to be the cause as it's all DC) or due to not using a choke on the incoming 12V supply. The max current on the humming 12V supply was also only 1amp which is marginal.