Roberts Rd-50 DAB Radio Sound/Volume Issue

[joebooooy]

Hi

I have a Roberts RD-50 radio which turns on fine and tunes to stations perfectly. The volume however, is barely noticeable when turned to max. I've tried a new charger and running the unit from batteries, but both had the same result.

I have also tried running the unit through another Roberts DAB radio speaker that I know has no issues, and the same problem occurred.

I have also tested the speaker in another radio and the speaker is fine, so that rules out a dodgy speaker!

Any help or tips to try and resolve the issue would be appreciated

Cheers

Joe

 

[Sam Gangee]

What's the history of the fault? When did it start?
How good is your knowledge of electronics?
What test equipment have you?

 

[joebooooy]

Hi there,

Thanks for your reply. My knowledge is fairly limited - I have swapped the speaker out but as far as testing individual components I wouldn't know where to start although I do have a multimeter here.

As for when the problem started it was around 4 months ago.

Thanks in advance

 

[Sam Gangee]

I assume that both left and right speakers are affected?
As you don't have the knowledge or test equipment, I suggest you take the radio to a repairer who has.

 

[joebooooy]

Thanks for your help, it's only got one speaker by the way.

Sounds like ill have to take it to someone in the know

Thanks again

Joe

 

[daxi]

Does it work normally on headphones??
If so, it sounds like a speaker problem & is thus probably an economic fix.

 

[ChrisFrost]

Does it work normally on headphones??
If so, it sounds like a speaker problem & is thus probably an economic fix.

He's already tried the speaker on another unit. He said that in the opening post. Did you miss it? Anyway, it worked fine. So I'd say that rules out a simple speaker problem.

It's not entirely clear from the description, but it looks like he's tried this unit as a source in to something else. The sound problem was still there. That means the issue is somewhere in the pre-amp or amplifier stage. So that means a faulty component. Now, unless there's something obvious to the eye when looking at the boards it falls to component level fault tracing. I wouldn't mind betting that this radio uses its fair share of surface mount devices. That's going to make it really hard for a DIYer. SMDs need specialist soldering equipment to avoid damaging surrounding components and so as not to fry the new part on fitting. Either that, or it's whole board replacements and then fingers crossed that there wasn't a cascade failure.

Ebay doesn't throw much up when it comes to Roberts spare parts. So if the product is out of warranty I'd say the simpler solution it to buy a tatty RD-50 and do a case swap.

 

[Sam Gangee]

I had an original RD-50* and it certainly didn't use SMDs. In fact the internal assembly was quite crude.

Here are some pretty pictures (not mine):
http://www.colisiumdevelopments.co.uk/page9.html

*Or was it an R500 ?

 

[ChrisFrost]

Well if you've seen the inside of one (or similar) then fair play to you. It using discrete standard sized components is potentially good news for the owner. I am surprised though but also secretly pleased that stuff can still be made that way.

There's very little on the web about the internals and effecting repairs on these radios. That does mean that there are not short cuts for an answer if it's an internal fault. The one thing I did pick up on is that the charger/mains adapter seems a bit of a weak link. There's been some reports that the voltage is low. If that's the case then perhaps the internal battery isn't charging properly. That might be worth a look.

 

[joebooooy]

Thanks for your replies - much appreciated

Just to let you know I did test with headphones too and the same problem occurs.

Would it help if I took some photos of the internal set-up at all?

Thanks again

Joe

 

[Sam Gangee]

As a minimum, you'll need

1. some sort of amplifier connected to headphones or a small loudspeaker. This would let you determine where the audio is OK (and where it ceases to be OK).

2. a circuit diagram of the audio section (or a very similar one).

3. some understanding of how audio amplifiers work, plus manual dexterity and basic tools.

 

[daxi]

Does it work normally on headphones??
If so, it sounds like a speaker problem & is thus probably an economic fix.

He's already tried the speaker on another unit. He said that in the opening post. Did you miss it? Anyway, it worked fine. So I'd say that rules out a simple speaker problem.

I was thinking of a headphone socket problem. It's not unheard of for these sockets, normally sourced as cheaply as possible, to cause problem. Sometimes some dirt or even a insect, can get into them & provide some conductivity & sometimes if they are used they fail to completely switch back to the speaker. But that is not what it sounds like..

 

[joebooooy]

Thanks for all the input and suggestions. Looks like I'll have to take it to a repair shop or even contact Roberts directly. I was hoping it was a common or obvious issue but it sounds like its a job for an expert.

Cheers all the same, I'll post a reply if I manage to get it sorted
Joe

 

[shuggywah]

Hi

I have a Roberts RD-50 radio which turns on fine and tunes to stations perfectly. The volume however, is barely noticeable when turned to max. I've tried a new charger and running the unit from batteries, but both had the same result.

I have also tried running the unit through another Roberts DAB radio speaker that I know has no issues, and the same problem occurred.

I have also tested the speaker in another radio and the speaker is fine, so that rules out a dodgy speaker!

Any help or tips to try and resolve the issue would be appreciated

Cheers

Joe

Hiya joebooooy, any chance you managed to get yer radio fixed? I've got the very same issue and it's p***ing me right off

Cheers

shug

 

[PyroBrit]

Hiya joebooooy, any chance you managed to get yer radio fixed? I've got the very same issue and it's p***ing me right off

Funnily enough, I was given an RD-50 yesterday with the same problem described here.

There does not seem to be any audio distortion but at max volume the audio is little higher than a whisper.

If I figure out what it is, I'll let you know. A schematic would be good to have but I haven't found one available.