Inside Squeezebox Radio

[majones]

My Radio was running continuously on external power but one day it died. I checked the power supply on another Radio and it was fine. I suspected that it may be the internal connection to the power input so I inserted a battery, and whoof my Q3 went up in smoke. So I’ve replaced that but it hasn’t got the Radio working again, and I’m wondering what the best sequence of replacement of items should be assuming (per the SB3 C16 and C20 capacitors) that there is a most likely failure mode. Any advice? I can solder capacitors, but that U2 power amplifier looks beyond my capabilities.

[JoeMuc2009]

Hi all,

got another failed Radio here, burnt Q3 and short circuit across the power amplifier outputs. However, it turned out that the short circuit continues to exist even after the power amp chip was desoldered.
The owner told me he was not aware of any battery in the device but the battery (original model) was actually in there. Seems that the battery being in there can trigger the self-destruction out nowhere anytime.
So I would recommend everyone to remove the battery for good and forget about it. Many devices seem to fail the moment the battery is inserted, but it might also happen in a power outage when the circuitry switches from external power supply to battery or back after external power is restored. Every one of these transitions is apparently very dangerous for the entire device.
Things around the battery look like an afterthought. Logitech seems to have implemented this part of the circuitry in a hurry. I can just say, do not use it.

Regards,
Joe

[SlimChances]

Hi all,

got another failed Radio here, burnt Q3 and short circuit across the power amplifier outputs. However, it turned out that the short circuit continues to exist even after the power amp chip was desoldered.
The owner told me he was not aware of any battery in the device but the battery (original model) was actually in there. Seems that the battery being in there can trigger the self-destruction out nowhere anytime.
So I would recommend everyone to remove the battery for good and forget about it. Many devices seem to fail the moment the battery is inserted, but it might also happen in a power outage when the circuitry switches from external power supply to battery or back after external power is restored. Every one of these transitions is apparently very dangerous for the entire device.
Things around the battery look like an afterthought. Logitech seems to have implemented this part of the circuitry in a hurry. I can just say, do not use it.

Regards,
Joe

I have not read the whole thread but your post caught my eye. Will using a battery in the SB Radio pose a fire hazard or is will it just possibly damage the radio? I have used mine on battery and on mains with the battery always inserted for a few years now with no issues. Is this just asking for trouble?

[slartibartfast]

Hi all,

got another failed Radio here, burnt Q3 and short circuit across the power amplifier outputs. However, it turned out that the short circuit continues to exist even after the power amp chip was desoldered.
The owner told me he was not aware of any battery in the device but the battery (original model) was actually in there. Seems that the battery being in there can trigger the self-destruction out nowhere anytime.
So I would recommend everyone to remove the battery for good and forget about it. Many devices seem to fail the moment the battery is inserted, but it might also happen in a power outage when the circuitry switches from external power supply to battery or back after external power is restored. Every one of these transitions is apparently very dangerous for the entire device.
Things around the battery look like an afterthought. Logitech seems to have implemented this part of the circuitry in a hurry. I can just say, do not use it.

Regards,
Joe

They can can fail without battery so this seems a bit over the top.

https://forums.slimdevices.com/showthread.php?p=861151

https://forums.slimdevices.com/showthread.php?p=909389

Sent from my SM-G900F using Tapatalk

[JoeMuc2009]

There's no way of knowing what is going to happen. It's true, the Radio can also fail without ever seeing a battery at all, but from what I read here, most of these incidents involve the battery so that's suspicious.

[habee]

Again Dead

So after it was working for 2 1/2 years my SB Radio died again. It went dead after it was running for several hours, before it was only used for a few minutes a day. Actually I am waiting for a new TPA but already replaced a blown diode (D6) which was short. I´ll keep you updated...

Bye habee

[habee]

Two Resistors (R328 and R316) are also blown. I think these were 10K Resistors, because the other ones around are. But they are so tiny, its hard to solder....

[edllew]

Radio working again, back from the graveyard

I posted in this thread in 2013 about my SB Radio dying. I just checked back in and thanks to subsequent forum posts, I was able to repair my radio last night and now have it restored and fully working. I replaced Q3 and found a bad capacitor by following the suggestion of ramping up supply current while feeling for hot components. If it helps anyone, the capacitor is C348. I replaced it with a 10nF cap. Now I have 2 working SB radios again. I will probably avoid using a battery pack on this newly repaired radio, since I suspect my homebrew battery might have been at least a partial cause of the original melt-down.

A few days ago I finally got around to looking at options for hosting my digital music collection on an at-home server. I am using a Raspberry Pi. I checked out Volumio and Moode also, and decided that piCorePlayer + LMS was the best. I am playing from the Pi via an I2C DAC ($15 AliExpress) into my Logitech Z-5300 5.1 amp+speakers (bought in 2006), and now using my 2 SB radios as players too. I like how they work together, syncronizing audio, etc. I made a small ESP8266-based controller to remote control the Z-5300 via MQTT / Node-Red I already had running locally on a separate Raspberry Pi.

Great fun to bring together parts old and new for minimal additional cost and have a nice sounding powerful system to play my music.

-Ed

[Paul Webster]

Welcome back after 9 years

[proditaki]

Good topic useful information.

My ue smart radio was dead. It had Q3 blown and a shorted cap near the TPA3101.

I replaced those and now it boots up. When i connect the speakers it gives pops and noises.

I removed the TPA3101 amp ic and listened over the earphone jack. This gives me loud noise in stead of audio as well. Doesnt get louder or quieter with the volume button as well

Ideas? Thanks a lot.

Update: turns out the AC3104 IC (U5) has issues so i ordered a replacement.

[JoeMuc2009]

Hi all,

I have another short story to add here. Thanks to my IR camera it was rather easy to fix.
Another radio arrived on the bench, not powering up at all with the stock power supply. A quick check proved the power supply was not at fault, it delivered 18.4V unloaded and still 17.45V with 1A load which is sufficient.
Visual inspection got me nowhere first. Q3 and Q5 were both in good shape and nothing else looked blown. However, a 10-Ohms resistance across the 18V circuitry looked suspicious. So it was rather clear I was tracing a short somewhere.
The IR camera helped so much here! It indicated a pulsing heat spike in Q5 propagating in the trace towards R239 (the nearby 0-ohms resistor probably acting as a kind of fuse). A similar pulse could be observed in the TDA amplifier chip's region. I found eventually that it was the tiny C348 on the front-facing side of the PCB which had gone low-resistance. Out of circuit it measures around 6 Ohms only. Desoldered this one component and everything is fine again! I think the Radio could live without it, however, I'll try and find a replacement for good measure.
On visual inspection it looked a bit fishy already while it was still soldered to the board. A macro image (attached) shows the tiny size and some cracks beneath the surface. Somewhere in there the electrodes of both sides are touching. The right side is a millimeter scale by the way.
So eventually I managed to save one! The first Radio that wasn't blown beyond repair. A tiny single component can ruin the whole show. Don't be fooled.

Cheers,
Joe

[proditaki]

Nice one!

The last Squeezebox Radio i repaired needed the AC3104 as i mentiond, had Q3 blown and a shorted capacitor :P
Most faults are repaireable as long as you don't blow out the main processor.