HK Center speaker 2014 W212
#52
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MY'14 W212 M276 3.5NA @60kMi
Amp comps: Main vs. Woofer...
2x 2200uF/25V caps
PCB overall view heatsink cuts
This small amplifier is driving out woofer tranducer on the rear deck. It's built around the same TDA IC chips as the main unit.
What we find here are caps use a safe 25v margin and they are 2200uF per chip exactly the minimum value recommended by the chip manufacturer.
The theme is caps got underated in both voltage and capacitance size.
Let me ask this:
-- What good did that do to derate these 15¢ part on the fancy main amp board?
-- It's not like they run out of space or did not know the minimum recommended values...
> Main Amp caps:
has 3300uF x3 = 9900uF/16V
needs 2200uF x5 = 11000uF/25V
needs better than 3x 3700uF
standardized value 4700uF
> Caps selection:
(Stock 3x 3300uF/16!V@105°C)
Good 3x 3300uF/25V@105°C
Better 3x 4700uF/25V@125°C glued with RTV
choices 'R US!
Last edited by CaliBenzDriver; 07-11-2022 at 07:10 PM.
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jd75025 (12-10-2022)
#54
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note the later 212's no longer have a separate sub amp, the sub is driven from the main amp. for what that all is worth. not sure what year they swapped.
#55
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MY'14 W212 M276 3.5NA @60kMi
the poor and the rich pay more 🤪
I wonder what goes on backstage: does MB back charges HK account for ALL warranty repairs? Suppliers then make up for losses with OEM parts contracts, right?
There is a fine line where suppliers help dealers ring up customers with services and the early failures turned into warranty claims.
Last edited by CaliBenzDriver; 07-12-2022 at 12:58 PM.
#56
Senior Member
2016 W212 (E63)
Center speaker was "replaced" by MB under warranty due to buzzing, mostly on phone calls but certain Sirius stations as well.
Failed again recently, about a year after the MB "replacement". I use air quotes because when I popped the center grill the center cone on the speaker had a giant dent in it. So much for a replacement. When I pulled the speaker out the center cone just fell off, so the glue job failed and was just resting on its last bit of glue.
Easy fix - get speaker glue or any other kind of rubber glue (I used patch glue for rainproof jacket) and reattach the cone. Done and done.
Center speaker was "replaced" by MB under warranty due to buzzing, mostly on phone calls but certain Sirius stations as well.
Failed again recently, about a year after the MB "replacement". I use air quotes because when I popped the center grill the center cone on the speaker had a giant dent in it. So much for a replacement. When I pulled the speaker out the center cone just fell off, so the glue job failed and was just resting on its last bit of glue.
Easy fix - get speaker glue or any other kind of rubber glue (I used patch glue for rainproof jacket) and reattach the cone. Done and done.
#57
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MY'14 W212 M276 3.5NA @60kMi
loose spk cone
that's interesting, you're saying your (front center spk) buzzing was from the loose cone vibrating above the coil during it's normal traveling.
The coil insulation is not fried, just a little glue around the cone and all was perfect again...
Do you have any pics of that beauty?
The coil insulation is not fried, just a little glue around the cone and all was perfect again...
Do you have any pics of that beauty?
Last edited by CaliBenzDriver; 07-12-2022 at 04:20 PM.
#58
Senior Member
that's interesting, you're saying your (front center spk) buzzing was from the loose cone vibrating above the coil during it's normal traveling.
The coil insulation is not fried, just a little glue around the cone and all was perfect again...
Do you have any pics of that beauty?
The coil insulation is not fried, just a little glue around the cone and all was perfect again...
Do you have any pics of that beauty?
But it works great now. Here's a stock photo, the brown part is what separated and was buzzing around.
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CaliBenzDriver (07-12-2022)
#59
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MY'14 W212 M276 3.5NA @60kMi
Front SPK dome
Here are couple pics I took on my way to glueing the wanna be loose fiber dome ...
Pop front snaps up then slide towards the rear
part designation (~$65Ea.)
3x dabs of 5mn epoxy: strong & light weight 😊
For reference I measured the two coils resistance at 2.Ohms and 8.Ohms individually. The lowest one likely used to drive more power from this tiny speaker.
Pop front snaps up then slide towards the rear
part designation (~$65Ea.)
3x dabs of 5mn epoxy: strong & light weight 😊
For reference I measured the two coils resistance at 2.Ohms and 8.Ohms individually. The lowest one likely used to drive more power from this tiny speaker.
Last edited by CaliBenzDriver; 07-12-2022 at 11:49 PM.
#61
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For reference I measured the two coils resistance at 2.Ohms and 8.Ohms individually. The lowest one likely used to drive more power from this tiny speaker.
#62
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MY'14 W212 M276 3.5NA @60kMi
dual coils for safety
I guess this was good for safety while mBrace lasted.
Last edited by CaliBenzDriver; 07-13-2022 at 09:36 PM.
#63
I follow the recommendations, replaced the capacitors - the problem is solved!
The only think, buy capacitors 21 mm toll. Otherwise you will have to cut the body of the amplifier - pain.
If you cannot find caps of 21 mm with 4700mF, go for 3300mF.
Mercedes (if you read), take a note - my read woofer burned in four years
The only think, buy capacitors 21 mm toll. Otherwise you will have to cut the body of the amplifier - pain.
If you cannot find caps of 21 mm with 4700mF, go for 3300mF.
Mercedes (if you read), take a note - my read woofer burned in four years
#64
I follow the recommendations, replaced the capacitors - the problem is solved!
The only think, buy capacitors 21 mm toll. Otherwise you will have to cut the body of the amplifier - pain.
If you cannot find caps of 21 mm with 4700mF, go for 3300mF.
Mercedes (if you read), take a note - my read woofer burned in four years
The only think, buy capacitors 21 mm toll. Otherwise you will have to cut the body of the amplifier - pain.
If you cannot find caps of 21 mm with 4700mF, go for 3300mF.
Mercedes (if you read), take a note - my read woofer burned in four years
I am going through this now, I heard the center speaker popping, smelled burning, and then smoke in the span of an hour while driving out of town. I was ****ting bricks thinking the car will burn down on a highway shoulder, an hour away from any major town. Fortunately had cell service and googled center speaker smoke and got to this thread.
Thanks for all the great info, I took the 40 amp fuse out and didn't see any more smoke or burning smell and was able to carry on my trip (albeit without music)
I know this post is a few months old but can you please link what 21mm caps you used? I don't have the means to mill down the amp housing. plug and play would be great.
I pulled my amp out today, here is a video to help with that, slightly different for cars with cargo rings and parktronic but very similar
Thanks in advance
Edit: found these on Digikey ELBK250ELL422AL20S
16mm D x 20mm L x 7.5mm lead spacing. Specs are a little different than those suggested by @CaliBenzDriver , wondering if they will work.
Last edited by adahm; 06-03-2023 at 07:43 PM.
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MemberLogic (06-05-2023)
#65
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MY'14 W212 M276 3.5NA @60kMi
Supersizing back to normal
these cap specs are all right, check the physical fit before you order.
digikey specs
The amplifier filtering was undersized so we are upsizing its caps as much as possible.
digikey specs
The amplifier filtering was undersized so we are upsizing its caps as much as possible.
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#66
These are the exact ones I ordered last week! I haven't had a chance to remove my amp yet but they looked to be the the most appropriate caps available at Digikey based on the info here.
EDIT: Maybe these would have been better? https://www.digikey.com/en/products/...MM20S/10486416
I should have some time to remove the amp today and check the diameter/lead spacing.
EDIT: Maybe these would have been better? https://www.digikey.com/en/products/...MM20S/10486416
I should have some time to remove the amp today and check the diameter/lead spacing.
Last edited by MemberLogic; 06-05-2023 at 09:56 AM. Reason: Clarification
#67
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do note these are electrolytic capacitors, and are polarized, you MUST get the + side correct or your new caps will become firecrackers and let the magic smoke out Its usually marked with a white stripe that has ++++++ running down it on one side of the cap... before removing the old ones, note where that is. Usually the 'silk screen' on the printed circuit board will indicate it, too, or maybe even the solder pads, like a larger square solder pad for the + side
#68
These are the exact ones I ordered last week! I haven't had a chance to remove my amp yet but they looked to be the the most appropriate caps available at Digikey based on the info here.
EDIT: Maybe these would have been better? https://www.digikey.com/en/products/...MM20S/10486416
I should have some time to remove the amp today and check the diameter/lead spacing.
EDIT: Maybe these would have been better? https://www.digikey.com/en/products/...MM20S/10486416
I should have some time to remove the amp today and check the diameter/lead spacing.
Last edited by adahm; 06-05-2023 at 03:26 PM.
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CaliBenzDriver (06-05-2023)
#69
It looks like the caps are 18mm with 7.5mm lead spacing. It was a little more difficult to get measurements on the height but with the board it was about 22.75mm and the board was about 1.40mm thick so I think 21.5mm is a safe bet.
Based on the input from others these seem to be the best option available at digikey:
https://www.digikey.com/en/products/...MM20S/10486416
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CaliBenzDriver (06-12-2023)
#70
MBWorld Fanatic!
digikey rocks, thats always been my favorite place to get electronic components going back to the 80s pre-internet... they published an inch thick catalog a few times a year
lead spacing can easily be fixed with a small pair of needlenose pliers
lead spacing can easily be fixed with a small pair of needlenose pliers
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CaliBenzDriver (06-12-2023)
#71
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hmm, it has higher capacitance and probably would have been better. I already ordered the other ones. I wonder why this didn't pull up on the filter search, I filtered by max height 22mm and the ones you linked show 21.5mm. the current ones appear to be around 17mm in dia, there may be just enough room to squeeze 18mm in there.
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CaliBenzDriver (06-12-2023)
#72
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MY'14 W212 M276 3.5NA @60kMi
combating unnecessary glitches
yes!... the wisdom is you want to max out both the physical and the electricals:
> Hints:
What causes spikes above the alternator 14.9V Max voltage.... a poor single oxidized"Chassis-Tranny" GND strap!
> Loosing the glitches:
Reliable vehicles use multiple GND straps to offer parallel paths - That's exactly what you want to prevent high-power spikes from heavy PWM engine fan.
> Remember:
{1/R = 1/R1 + 1/R2 + 1/R3 }
Simply means "parallel paths help drastically lower dynamic resistance to high current".
A single engine GND strap is amazingly unreliable to conduct 100% ALL power.
Upgrade your filtering capacitors back to a normal range and understand the Benz playground environment.
+++++ Heatsink thermal paste :
You know the rules: "EVEN-STEVEN" thin layer to transfer the heat from IC-packaging to heatsink.
- the upgraded voltage dielectric
- the more microFarad
- the right height /diameter /pin spacing
> Hints:
What causes spikes above the alternator 14.9V Max voltage.... a poor single oxidized"Chassis-Tranny" GND strap!
> Loosing the glitches:
Reliable vehicles use multiple GND straps to offer parallel paths - That's exactly what you want to prevent high-power spikes from heavy PWM engine fan.
> Remember:
{1/R = 1/R1 + 1/R2 + 1/R3 }
Simply means "parallel paths help drastically lower dynamic resistance to high current".
A single engine GND strap is amazingly unreliable to conduct 100% ALL power.
Upgrade your filtering capacitors back to a normal range and understand the Benz playground environment.
+++++ Heatsink thermal paste :
You know the rules: "EVEN-STEVEN" thin layer to transfer the heat from IC-packaging to heatsink.
Last edited by CaliBenzDriver; 06-12-2023 at 01:17 AM.
#73
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traditionally wiring practices are one good ground, NOT multiple ground straps, as you can get some weird RF oscillations with multiple ground paths.
the alternator should be well grounded to the chassis, and the engine block should also be well grounded to the chassis. ditto the battery(s).
our 'smart' alternators are more likely running at 12.6-12.8V than at 14.x V most of the time, once the battery is recharged from the starting current.
the alternator should be well grounded to the chassis, and the engine block should also be well grounded to the chassis. ditto the battery(s).
our 'smart' alternators are more likely running at 12.6-12.8V than at 14.x V most of the time, once the battery is recharged from the starting current.
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CaliBenzDriver (06-12-2023)
#74
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MY'14 W212 M276 3.5NA @60kMi
single or parallel GND ...
traditionally wiring practices are one good ground, NOT multiple ground straps, as you can get some weird RF oscillations with multiple ground paths.
the alternator should be well grounded to the chassis, and the engine block should also be well grounded to the chassis. ditto the battery(s).
our 'smart' alternators are more likely running at 12.6-12.8V than at 14.x V most of the time, once the battery is recharged from the starting current.
the alternator should be well grounded to the chassis, and the engine block should also be well grounded to the chassis. ditto the battery(s).
our 'smart' alternators are more likely running at 12.6-12.8V than at 14.x V most of the time, once the battery is recharged from the starting current.
but
when heavy power is involved parallel is redondant paths... look at properly GND Japanese cars.
It would be nice also to not rely on aluminum for conduction because the aluminum oxide is an insulator. I dont want to get to crazy with bridging the aluminum engine block with bypass cables, we can leave with that and a secondary or more straps.
✌️
Last edited by CaliBenzDriver; 06-12-2023 at 01:28 AM.
#75
Everything went well with the cap swap and I've reinstalled them amp and amp fuse. Feels great to have audio back again!
It seems like the only speaker that burnt out was my rear subwoofer. Would that have been caused by the caps in the main amp since the sub has it's own amp?
I'll have to look into replacing the burnt out sub this week. Don't think I can stand the rattling much longer.
It seems like the only speaker that burnt out was my rear subwoofer. Would that have been caused by the caps in the main amp since the sub has it's own amp?
I'll have to look into replacing the burnt out sub this week. Don't think I can stand the rattling much longer.