I have a Lanzar 100 (old school) car amplifier that dug out to try in my kids car.
It haven't been used for a looong time so i wasn't sure if it would start at all. It played for a few weeks but now it stopped working.
The power lamp comes on but no sound from it.
I checked so there is signal from the stereo both rca and remote. Eventually found that diode D6 was literally broken in 2 pieces when i started to measure the components.
I cannot read the values on it and was hoping that maybe someone could help me with this and if there maybe is something else that is not ok that made the diode fail. Attached some pictures of the amp.
Thanks in advance.
It haven't been used for a looong time so i wasn't sure if it would start at all. It played for a few weeks but now it stopped working.
The power lamp comes on but no sound from it.
I checked so there is signal from the stereo both rca and remote. Eventually found that diode D6 was literally broken in 2 pieces when i started to measure the components.
I cannot read the values on it and was hoping that maybe someone could help me with this and if there maybe is something else that is not ok that made the diode fail. Attached some pictures of the amp.
Thanks in advance.
Attachments
There's a good chance that it's a 1N4148 diode like D7. The zener diodes appear to use the prefix ZD, not simply D.
Thanks for a quick reply!
There are a few of these diodes with different specs regarding Volts and Ampere. Any idea what I should go with? Found one that says 75V and 150 mA (1N4148 SOD-27) will that one be good? Also wondering what may have caused it to fail, maybe just old age / bad luck?
There are a few of these diodes with different specs regarding Volts and Ampere. Any idea what I should go with? Found one that says 75V and 150 mA (1N4148 SOD-27) will that one be good? Also wondering what may have caused it to fail, maybe just old age / bad luck?
I have no clue how it's being used so I can't tell how/why it failed. It is possible that it was a random, age related failure.
1N4148s are typically 100v, 200ma but if it's listed as a 1N4148 and it's through-hole, it will likely work as expected.
1N4148s are typically 100v, 200ma but if it's listed as a 1N4148 and it's through-hole, it will likely work as expected.
Yes, I understand that you cant tell that without any info. I ordered the diode to replace the faulty one and se if it will work.
Thanks for the quick help so far!
Thanks for the quick help so far!
So i received the new diode and replaced it. Still no luck. Amp turns on but nothing comes out of it. One transistor (marked on photo) gets some heat after a while with the amp and stereo running, not hot but lukewarm so i guess something is going through?
I measured the speaker output on the amp while playing and it reads ~0.5-0.75V.
Any advice on what could be wrong or where to start checking?
I measured the speaker output on the amp while playing and it reads ~0.5-0.75V.
Any advice on what could be wrong or where to start checking?
Attachments
Is the amp producing rail voltage?
What is the DC voltage on the power supply terminals of the op-amp under the gain pot?
You'll likely need to use the secondary ground for the black probe.
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)
What is the DC voltage on the power supply terminals of the op-amp under the gain pot?
You'll likely need to use the secondary ground for the black probe.
Please (and this applies to anyone who needs repair help) use your sig line to list all equipment you have, editing it as equipment changes. Include the model numbers.
Top of page, menu USER CP >> EDIT SIGNATURE
Oscilloscope (yes or no)
Multimeter(s)
Type of signal source (grounded RCA shields preferred).
Soldering iron
Desoldering pump
Power supply
2 ohm current limiting resistor (hollow cylindrical ceramic 100w preferred)