in the photo the voltages tested I await your news thanks
the points highlighted refer to VDDP (+) VSSP (-)
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Re: Db Technologies Cromo 12 amplifier no audio
in the photo the voltages tested I await your news thanks
the points highlighted refer to VDDP (+) VSSP (-)Last edited by falcontech; 10-23-2020, 11:05 AM. -
Re: Db Technologies Cromo 12 amplifier no audio
The inductor value will be printed on the inductor itself not on the circuit board since the design may be changed.
220 will be 22uH.Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
certainly the same abbreviation has been removed from the PCBLeave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
https://www.badcaps.net/forum/attach...6&d=1603290566
I only see two large output inductors. What are the printed on top of the inductors?
The value of the inductors are based on impedance of the load.Last edited by budm; 10-22-2020, 01:34 PM.Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
very well I understand, tomorrow I'll let you know, what about inductances what do you tell me?Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
The Voltage testing will be reference to the circuit ground, the unit has dual power supplies (BIPOLAR power supply), one for the positive supply with ref to the circuit ground, and another one is Negative power supply with ref to circuit ground.Last edited by budm; 10-22-2020, 01:09 PM.Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
I forgot, I tested those inductances that are next to the capacitors, which should have 22 uH, only one has 22uH the other three reach 30uH more or less, I suppose they are normalLeave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
ok for the assembly of the capacitor I will try to be careful, do you have any advice not to damage it while soldering? as for the output voltage tomorrow i will try, so i have to put the positive lead on the VDDP and the negative lead on the VSSP?Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
VDDP, VSSP are power supply Voltages.
It will be the same Voltage as on VDDP2.
According to the spec sheet, the typical Voltage for VDDP (+)/VSSP (-) as shown on page 13 is +/-30VDC.Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
i have not tried if i have output voltage on pin 14, what voltage should i have at output on pin 14?Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
https://cdn.badcaps-static.com/pdfs/...6bfeac6d82.pdf
The schematic on page 22 is for TDA5950J which does not have the same pinout as TDA5950TH, see page 5 for pinout. The 15nf is used on the Boot strap pin.
1) So the cap on pin 14 VDDP1should be around 100nf, same value as used on VDDP2.
2)So you do have Voltage feeding VDDP1?
3) That cap is MLCC (Multi Layer Ceramic Capacitor), the failure mode is shorted circuit, you have to handle it very carefully when installing them, you need to make sure it is not shorted out after installation since they can easily be damaged.Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
I replaced the capacitor with a 15nf one, suggested by the guy from the YouTube video but looking at the IC schematic that 15nf is on the boot1 pin so I think I was wrongLeave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
Yes pin 14 vddp1Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
Did you look up the spec sheet of the TDA8950th?
What pin of the IC the burnt capacitor is connected too?Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
anyone who can help me?Leave a comment:
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Re: Db Technologies Cromo 12 amplifier no audio
If it helps this is a video of the same amp that has been repaired
https://www.youtube.com/watch?v=pB_XobWmlp8&t=72sLeave a comment:
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Db Technologies Cromo 12 amplifier no audio
good morning
I have a problem with this amplifier of a DB Technologies chrome 12 powered speaker, I have no output sound, I tried to change (for the moment) only the woofer power amp which is un tda8950th and that little ceramic capacitor highlighted in the photo that was burned when I turn on the amplifier I have the regular signal on the green LED but nothing at the output, the amplifier diagram is not available if someone could help me to repair it I would be grateful PS the components of the case are functional so this problem is excludedAttached FilesLast edited by falcontech; 10-21-2020, 08:32 AM. -
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The Problem: This player has a toggle switch to select between Stereo, Mono R, and Mono L. Regardless of the setting it outputs the sound to both the L&R audio jacks. In the Mono R position, the audio output level is normal (from both the L and R audio output jacks), in the Stereo position the audio output is about half the volume, and in Mono L, it's about 3/4 the volume. Something about putting it into Stereo mode is causing the volume to drop significantly and I can't figure it out.
The player processes the audio signal using two different reference frequencies. The "R"... -
Well for RF transmitters, transmitting without an impedance matched antenna and if the transmitter doesn't have automatic limiting... kiss the final transistor goodbye and chalk one up to something you killed.
But that's not the same way with audio amps for the most part, well, at least the wavelength of audio on copper is so long that you get all of it back anyway but the transistor is fine with it...
So how are people destroying finals in their audio amplifiers then? Heh.
Are people shorting their outputs or something, overdriving output to a too big speaker?... -
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Now i didn't have any replacements of the same model of course but i found a couple with pretty similar spec i thought (K10A60D & K12A50D) and put them in. Also replaced the blown fuse with a 3.5A250V one. Checked another time for short circuit and plugged it in.... -
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I've got a pair of speakers with an amp built in to them in for repair and on inspection I can see the TDA2030A amplifier ICs have blown (so I've ordered some spares which should arrive soon):
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