Awesome video, everything so far described sounds like my exact issue with my current and brand new amplifier. It is a 5207 that has been sitting since it was new because i haven't been able to get it to work.
Awesome! All the components seem to be very similar to my amp. So far I've checked all the power supply and output FETS and none are shorted. This week i'll be going through with a magnifying glass to inspect the solder joints. It's been a while since I tried firing it up so I don't even remember the symptoms but I think it never powered up to begin with. Last year when I fiddled with it, I remember replacing the power supply caps (upstream of transformer) and it still didn't fire up.
So I ended up finding a service manual for a KAC-8104D which is VERY close to 8105D. Has all the part numbers and schematics that I need. I went through and checked all mosfets, voltage regulator transistors, rectifiers, all the solder joints...and it all looks good. The only thing now is checking some voltages with the power hooked up. Will I be able to check rail voltages (+/- 65V) and other voltages throughout the circuit with just a multimeter? I don't have a scope. Also, do I need to have the remote wire connected for the rail voltages to build?
Yes you can check the rail voltages with just a multi meter. Put the black probe on the amp negative input, and measure the center pin of the rectifiers. You will get a positive and negative voltage depending on which rectifier you check. You can also measure with one probe on one rectifier center leg, the other probe on the other one to get the full rail to rail voltage. Caution! one slip and you can make big sparks and destroy parts, not to mention possibly get hurt, be careful. A scope is required to check signals, like power supply and output drives. Next video up will show a power supply repair, look for it this week!
Hi, I have 2000w Kac-ps917D Kenwood amp as soon as I increase the volume it goes into protection mode, after troubleshooting found out that there is continuity between +ve and -ve power terminal checked the caps and fets everything is fine, any idea what should I look for?
You will get continuity on the power and ground terminal until the input filter capacitors charge (see lots of my videos). You probably have DC offset on the output, and as the volume goes up the offset increases and the amp goes into protect. One or more of output transistors is probably hurt.
I've been using this amp for over 3 years with no problems. The other day I was running my sub much louder than usual for an extended period of time on a very hot day, and it cut out suddenly. I opened my trunk and felt the amplifier and it was extremely hot to the touch. Since then I have not been able to get it to work again. When I turn my car on the red light on the amp doesn't turn on. The fuses on the amplifier and near the car battery are both intact. What next steps would you recommend?
I am not taking in repairs at this time, it is still just a hobby for me. There are a lot of shops, what is your general location and I might be able to point you to someone close.
Hey! I have a question. I have an old Kenwood A322 amp. It sounded great, until it didn't. 2 of the wires touched for a long time apparently, and one of the fuses blew out. So one of the channels didn't work anymore. I changed the fuses, got new wires that are high quality, so without exposed copper that can touch eachother. Now the sound is extremely distorted, and scratchy. It's not the volume knob. I think i blew up a transistor or something, but I'm not sure. Any ideas what this could be?
If it blew the fuses, most likely the power supply side is blown, in combination with a blown output, but it could be just blown output and the power supply is surviving long enough for the fuses to blow.
mines has no power no indication light or anything took it apart and took my volt meter on it like u did and there all good any ideas? nothing Burnt and yes my wiring was correct I hooked up a different amp to the same wires n it works fine. and also no it's not the fuses the amp Sparks when u connect the wire like it would be getting power but nothing getting hot and nothing happens
Each amp that I make videos on, I do the trouble shooting the same, be sure to check a couple others to make sure you understand how and what to check, some of the other videos show better angles etc. Once you have made it though the checks with your multi-meter, and you cannot find any burnt parts or broken solder or traces, then you will need to enlist an oscilloscope for further trouble shooting. I know not everyone has one, or wants to get one but don't let that stop you from trying. Your amp may be more badly broken, but the next amp you try might not.
@@Crazylogix007 I wish I could show a pic the power supply did look a little loose on the soider joints so re sorted the power supply there's a short some where within the board idk where tho I check all the parts on the meter and everything seems to be good above the number it supposed to but I can't find the Short
@@kyleh5356 If you know which ones are the rectifiers, you can note which one goes where and remove them. That will isolate the power supply from the output. you can then test powering up just the power supply. Check out BCAE1.com for great info on testing.
Video is 2 years old. My man still replying to fresh comments, way to go
Awesome video, everything so far described sounds like my exact issue with my current and brand new amplifier. It is a 5207 that has been sitting since it was new because i haven't been able to get it to work.
I'm glad I found ur video. Finding loose connections solved my problem. I had a compactors bad but still not, with ur help I found the problem
Great to hear!
Perfect timing on posting this video...I am beginning to start repairing my Kenwood KAC-8105D. The microscope cam works just fine btw.
Thanks, I still have this amp if you need to know a part number or something that is burnt up.
Awesome! All the components seem to be very similar to my amp. So far I've checked all the power supply and output FETS and none are shorted. This week i'll be going through with a magnifying glass to inspect the solder joints. It's been a while since I tried firing it up so I don't even remember the symptoms but I think it never powered up to begin with. Last year when I fiddled with it, I remember replacing the power supply caps (upstream of transformer) and it still didn't fire up.
So I ended up finding a service manual for a KAC-8104D which is VERY close to 8105D. Has all the part numbers and schematics that I need. I went through and checked all mosfets, voltage regulator transistors, rectifiers, all the solder joints...and it all looks good. The only thing now is checking some voltages with the power hooked up. Will I be able to check rail voltages (+/- 65V) and other voltages throughout the circuit with just a multimeter? I don't have a scope. Also, do I need to have the remote wire connected for the rail voltages to build?
Yes you can check the rail voltages with just a multi meter. Put the black probe on the amp negative input, and measure the center pin of the rectifiers. You will get a positive and negative voltage depending on which rectifier you check. You can also measure with one probe on one rectifier center leg, the other probe on the other one to get the full rail to rail voltage. Caution! one slip and you can make big sparks and destroy parts, not to mention possibly get hurt, be careful. A scope is required to check signals, like power supply and output drives. Next video up will show a power supply repair, look for it this week!
My kenwood amp KAC-9152D just went dead no burn smell and no signs of burn...changed all the fuses but still nothing...any pointers please
Hi, I have 2000w Kac-ps917D Kenwood amp as soon as I increase the volume it goes into protection mode, after troubleshooting found out that there is continuity between +ve and -ve power terminal checked the caps and fets everything is fine, any idea what should I look for?
You will get continuity on the power and ground terminal until the input filter capacitors charge (see lots of my videos). You probably have DC offset on the output, and as the volume goes up the offset increases and the amp goes into protect. One or more of output transistors is probably hurt.
I've been using this amp for over 3 years with no problems. The other day I was running my sub much louder than usual for an extended period of time on a very hot day, and it cut out suddenly. I opened my trunk and felt the amplifier and it was extremely hot to the touch. Since then I have not been able to get it to work again. When I turn my car on the red light on the amp doesn't turn on. The fuses on the amplifier and near the car battery are both intact. What next steps would you recommend?
Time to check the power supply and output fets, see a ton of my videos, its one of the first things to check.
How much will you charge me for repairing mine have power but no sound
I am not taking in repairs at this time, it is still just a hobby for me. There are a lot of shops, what is your general location and I might be able to point you to someone close.
I drop my amp stop working you give me good tips
Thanks!
Hey! I have a question. I have an old Kenwood A322 amp. It sounded great, until it didn't. 2 of the wires touched for a long time apparently, and one of the fuses blew out. So one of the channels didn't work anymore. I changed the fuses, got new wires that are high quality, so without exposed copper that can touch eachother. Now the sound is extremely distorted, and scratchy. It's not the volume knob. I think i blew up a transistor or something, but I'm not sure. Any ideas what this could be?
Might be the output transistors
My friend has the same amp and his has to bad MOSFET irf1z34g is there a substitute for it?
The IRFZ44 substitutes well for most fets in that family.
I have a kenwood that turns on but no sound comes on and it burned the fuses any idea?
If it blew the fuses, most likely the power supply side is blown, in combination with a blown output, but it could be just blown output and the power supply is surviving long enough for the fuses to blow.
Mine keeps blinking red?
mines has no power no indication light or anything took it apart and took my volt meter on it like u did and there all good any ideas? nothing Burnt and yes my wiring was correct I hooked up a different amp to the same wires n it works fine. and also no it's not the fuses the amp Sparks when u connect the wire like it would be getting power but nothing getting hot and nothing happens
Each amp that I make videos on, I do the trouble shooting the same, be sure to check a couple others to make sure you understand how and what to check, some of the other videos show better angles etc. Once you have made it though the checks with your multi-meter, and you cannot find any burnt parts or broken solder or traces, then you will need to enlist an oscilloscope for further trouble shooting. I know not everyone has one, or wants to get one but don't let that stop you from trying. Your amp may be more badly broken, but the next amp you try might not.
@@Crazylogix007 I wish I could show a pic the power supply did look a little loose on the soider joints so re sorted the power supply there's a short some where within the board idk where tho I check all the parts on the meter and everything seems to be good above the number it supposed to but I can't find the Short
@@kyleh5356 If you know which ones are the rectifiers, you can note which one goes where and remove them. That will isolate the power supply from the output. you can then test powering up just the power supply. Check out BCAE1.com for great info on testing.
Crazylogix007 will do thankyou for the help ill se what I can do
subscribed...
Thanks!
hello my friend a im from mexico city can you help me i gould like to ask you if you have a diagram schematich ? THANKS
I have some schematics, most have been found using google, or searching forum posts, like at diyaudio.com
👍
please insert Persian subtitles