Hi guys,
So my Velodyne sub was out of working. It powers on, the light is up, remote control ok, except that no sound coming out. Opened the unit and I got the burning smell from little box as per photo below.
Could anyone tell me what is this one and if I can have a cheap fix or need to order from Velodyne ? Or it's not worth it considering the repair price and buy a new one.
Cheers
So my Velodyne sub was out of working. It powers on, the light is up, remote control ok, except that no sound coming out. Opened the unit and I got the burning smell from little box as per photo below.
Could anyone tell me what is this one and if I can have a cheap fix or need to order from Velodyne ? Or it's not worth it considering the repair price and buy a new one.
Cheers
I would consider your board to be beyond economic repair but I am intrigued , is it really from a Velodyne ? I had imagined that Velodyne would have much better quality electronics inside, I am not wanting to take a poke at it as I consider their sub woofers are very good and have been bidding on a few different units on ebay , just surprised the pcb looks so cheap.
Looks like a whole load of magic smoke escaped from this sub - the genie has well and truly got out of the bottle.
Believe or not, no smoke at all (it is a sealed unit) and I didn't even know it was out, until was feeling something not right with bass when watching movie (not enough bass may be). As I got 5 subs altogether so if 1 was out, it's just hard to know anyway.
It is a small board, about 9cm in length and width and from the look, may be a stepdown power supply unit ?
It is a small board, about 9cm in length and width and from the look, may be a stepdown power supply unit ?
I dont know for certain but the fried board looks like the main amp , does it screw onto the faceplate mounted finned heatsink ? The amp is meant to be capable of 170W rms so I would have expected to see something more substantial for the output transistors. If your main driver is still ok then you could bypass the internal amp and connect a stand alone amp. I bought an old NAD THX2700 for £90 which can be switched to bridged mono output giving 400W rms and used this to bypass a blown faceplate amp on a sub , its sounds better than the original built in unit and a lot cheaper than getting a replacement amp but its yet another big black box taking up space . It would be easy to get a stand alone or even a small amp that could be squeezed in place of the existing amp but I think the CHT12 may have servo control which would then not work and I dont know how bad your Velodyne would sound without it .
I'm working on the same amp module (by the looks of it) from a 4000r. Velodyne would not provide any schematics for this amp as the 'technology was still in production'.
The capacitor that's blown by the relay is part of a snubber circuit and that's similar to what happened with mine. My guess is that the amp went into oscillation or the relay contacts went bad and took out the cap which caused further damage.
You said you have more of these amps/subs?
The capacitor that's blown by the relay is part of a snubber circuit and that's similar to what happened with mine. My guess is that the amp went into oscillation or the relay contacts went bad and took out the cap which caused further damage.
You said you have more of these amps/subs?
Your pictyres shows the main amp. It is a class d amp based on IRS20124, and to me it looks like an ok implementation. The output MosFets can actually be quite powerfull though only in TO220 cases.
You could purchase anoter class d amp and put in ..... guess it was rated as a few hundred watts.
Not easy to repair this one, as it seems the PCB is damaged as well.
Big question is how much EQ and other styff is included on the board ..... the most blackened area seems to be the input section, and therre is more components than needed for just the power amp ....... so this makes repair more difficult .... maybe just try to get a new board from Velodyne ....... but maybe ask Velodyne how this can happen .... I think something is wrong with the design, if this happens to a lot of units, and by the look of the damage could it start a fire?
You could purchase anoter class d amp and put in ..... guess it was rated as a few hundred watts.
Not easy to repair this one, as it seems the PCB is damaged as well.
Big question is how much EQ and other styff is included on the board ..... the most blackened area seems to be the input section, and therre is more components than needed for just the power amp ....... so this makes repair more difficult .... maybe just try to get a new board from Velodyne ....... but maybe ask Velodyne how this can happen .... I think something is wrong with the design, if this happens to a lot of units, and by the look of the damage could it start a fire?
I just finished repairing a similar amp module for a model 4000r. It's back home now and I hope it lasts a long time. There were problems in both the amplifier and power-supply (a combination of poor design and components).
I agree with the above from Baldin and it's a shame that a respected company would sacrifice reliability like this. Schematics are not available but you should be able to buy a complete plate-amp from Velodyne. Not sure if the problems have been corrected (I doubt it) but I would expect similar failure in the rest of the units in due time.
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