A BAV21 is a standard diode. Any diode rated for 1 amp or more and 250v or more should work in it's place. A 1n4004 would work. Depending on the rail voltage, a 1n4003 may work also.
Did it fail shorted or is it leaking (electrically)?
http://sigma.octopart.com/135193/datasheet/Philips-BAV21.pdf
Did it fail shorted or is it leaking (electrically)?
http://sigma.octopart.com/135193/datasheet/Philips-BAV21.pdf
ok thanks Im gonna be ordering some parts later. Wondering is a ksa916 the same as a 2sa916 transistor wondering before i order parts
Should be the same transistor but check a datasheet if in question, I had one the other day that was right number but different company and was completely different part when it came.
ok i got this amp out of protection mode powers up fine and produces output. But only the left channel has output. The right channel has a very low hiss sound coming out wondering what i should check from here
Check the signal coming out of the op-amps. Do both channels make it through all of the op-amps?
i found a bad op amp in the right channel the op amp they use is an njm2068L. i have some njm4558L's laying around wondering if they will work in the njm2068l's place
wondering if i did something wrong i replaced the op amp with the 4558l and the amp went into protection and blew a diode in the right channel. wondering if the 4558 would cause that problem
Without knowing where the diode is in the circuit and how it's being used, it's impossible to know if the op-amp could have caused it.
Generally, if the op-amp isn't stable in the circuit it will cause the amp to draw excessive current or it will cause outputs to fail. On the bench, you rarely have any damage because there are safety devices in use.
Generally, if the op-amp isn't stable in the circuit it will cause the amp to draw excessive current or it will cause outputs to fail. On the bench, you rarely have any damage because there are safety devices in use.
the diode that blew is a 1n4744 wondering if i can sub it for something else to test amp until i order a new one
Ok found a diode out of another amp i had and replaced the bad one.
I checked the op amps all seem to be fine now but still no output in the right channel.
wondering where do i go next coulod the problem be in the power supply section or most likely in the output section
sorry just wanna get this thing fixed im so frustrated with this amp
I checked the op amps all seem to be fine now but still no output in the right channel.
wondering where do i go next coulod the problem be in the power supply section or most likely in the output section
sorry just wanna get this thing fixed im so frustrated with this amp
Does it have muting transistors? They are often tiny through-hole transistors located between the preamp and power amp sections on the board. You should see audio on one leg of the muting transistors. If you see it on the good channel but don't for the dead channel, remove the one for the dead channel to see if the audio returns. If you still don't see audio, the problem is in the preamp section.
If you have audio on the muting transistors, compare the DC voltage on all of the transistors of the two channels.
If you have audio on the muting transistors, compare the DC voltage on all of the transistors of the two channels.
the muting transistors checked fine. wondering then traced the circuit from the muting transistor to a disk cap wondering how do i check thoose and also how do i check the mylar caps
1 last thing i was checking some resistors like the 100 ohm ones in the circuit and they are reading like 94.8 wondering is this still ok or should i replace theese
This amp has been nothing but a headache someone tryed fixing it before i bought it and had alot of wrong parts in it and stuff missing off the board alot of phone calls and posting here is got me closer to trying to figure this thing out and i apperivate all the help
1 last thing i was checking some resistors like the 100 ohm ones in the circuit and they are reading like 94.8 wondering is this still ok or should i replace theese
This amp has been nothing but a headache someone tryed fixing it before i bought it and had alot of wrong parts in it and stuff missing off the board alot of phone calls and posting here is got me closer to trying to figure this thing out and i apperivate all the help
Checking them with an ohm meter, the capacitors should read as an open circuit. If your meter has a capacitor checker, you can determine if they're within tolerance. They should not read shorted (they rarely fail).
The 100 ohm resistor is probably OK. Being just slightly out of tolerance (for a 5% resistor) shouldn't not cause you to have no audio.
After pulling the muting transistors, did you have audio on any of its pads?
If not, you have problems in the preamp section.
If you find audio on the muting transistor for the other channel, but not on the dead channel, you should be able to connect a jumper between the pads for the muting transistors (the ones where you have audio on one channel) to see if the dead channel works.
The 100 ohm resistor is probably OK. Being just slightly out of tolerance (for a 5% resistor) shouldn't not cause you to have no audio.
After pulling the muting transistors, did you have audio on any of its pads?
If not, you have problems in the preamp section.
If you find audio on the muting transistor for the other channel, but not on the dead channel, you should be able to connect a jumper between the pads for the muting transistors (the ones where you have audio on one channel) to see if the dead channel works.
Ive just went through the entire right channel everything checks fine. So now im going into the preamp section. Im gonna be checking the diodes resistors and transistors since the first check of the parts all tested fine.
Wondering if a resistor or diode is bad will it still read good if there is the same value resistor in line with it
Wondering do i need to unsolder at least 1 lead on a resistor or diode and pull it out of circuit to test them since in curcuit everything is testing fine but no audio on right channel still
Wondering if a resistor or diode is bad will it still read good if there is the same value resistor in line with it
Wondering do i need to unsolder at least 1 lead on a resistor or diode and pull it out of circuit to test them since in curcuit everything is testing fine but no audio on right channel still
Feed signal to the left channel only and check for signal on every op-amp output (pins 1 and 7 for most 8 pin op-amps). Using a sharpie marker, mark each output that has signal when the left channel is driven. Then move the signal to the right channel and again check for signal. If the left channel is on pin 1 of most all of the op-amps, there's a good chance that the right channel will be on pin 7. Find the point in the circuit where you have left channel signal on one op-amp and no right channel signal on that same op-amp.
Im putting this amp back together so i can test it. My 3 year old took off and lost 1 of the muting transistors. they are marked c343 tsc wondering if anyone has a part number for theese any help would greatly be appericated
These are probably the part you need:
http://octopart.com/search?q=DTC343
What did you find wrong with the amp?
http://octopart.com/search?q=DTC343
What did you find wrong with the amp?
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