Hello,
I am new to this forum and apologize if I am in the wrong section.
I need help. As the title reads, I have a ppi amp that powers up, appears to be spotless inside, nothing looks burned or smells fried. I got it this way. I know it isn’t anything on my side because I swapped it for my other amp that is identical and works in that vehicle, this one just has no sound.
I am an HVAC Technician but this is beyond my skill.
Any easy fix would be awesome or if you know someone that could fix it for me, I wouldn’t mind paying. I prefer old school amps.
Thanks,
Scott Murphy
I am new to this forum and apologize if I am in the wrong section.
I need help. As the title reads, I have a ppi amp that powers up, appears to be spotless inside, nothing looks burned or smells fried. I got it this way. I know it isn’t anything on my side because I swapped it for my other amp that is identical and works in that vehicle, this one just has no sound.
I am an HVAC Technician but this is beyond my skill.
Any easy fix would be awesome or if you know someone that could fix it for me, I wouldn’t mind paying. I prefer old school amps.
Thanks,
Scott Murphy
Do you know what (in general) the various parts are in the amp?
Does this amp have internal clamps for the semiconductors or does it use the cover for clamping the semiconductors to the heatsink?
Does this amp have internal clamps for the semiconductors or does it use the cover for clamping the semiconductors to the heatsink?
OK. The following link shows how to work with them.
https://www.diyaudio.com/community/threads/jl-audio-500-1-transistor-clamps.109539/post-1317683
https://www.diyaudio.com/community/threads/jl-audio-500-1-transistor-clamps.109539/post-1317683
Why would I take those clamps off? What would I be doing? Is there something I should be testing? Everything appears to look normal. Amp powers up, green light, but no sound.
Thanks for your help
Thanks for your help
Have you tried operating all of the pots and switches through their entire range with a signal source connected and a speakers connected to the amp to see if it ever produced any sort of sound (even if it was just static/noise)?
If the amp never produced any sounds, measure the DC voltage across pins 4 and 8 of the 8-pin op-amps. What's the voltage?
Just FYI on the clamps.
If the amp never produced any sounds, measure the DC voltage across pins 4 and 8 of the 8-pin op-amps. What's the voltage?
Just FYI on the clamps.
Yes, I ran through all of the switches and gains and inputs. I have another amp almost identical that works and I installed this amp in its place and tried everything possible and nothing.
I have a meter and I’m an HVAC tech but no nothing about amplifiers or where to check for voltage and what the values would be.
I really wish I could find someone to fix the amp and I would pay them. I just don’t know anyone local that works on them and don’t know where to send it off to where I could trust someone not to try to keep my amp or tell me something crazy is wrong with it…,like mechanic shops do people.
I was hoping someone would know a simple fix. These amps are robust and I really don’t see anything wrong with it. In my business normally I would see a burnt transistor or compositor, the smell of a burnt transformer but I really don’t know what I’m looking for or where I should be looking.
I’m sure it would be a simple fix for you, I am just at a loss for a fix.
I appreciate your help
I have a meter and I’m an HVAC tech but no nothing about amplifiers or where to check for voltage and what the values would be.
I really wish I could find someone to fix the amp and I would pay them. I just don’t know anyone local that works on them and don’t know where to send it off to where I could trust someone not to try to keep my amp or tell me something crazy is wrong with it…,like mechanic shops do people.
I was hoping someone would know a simple fix. These amps are robust and I really don’t see anything wrong with it. In my business normally I would see a burnt transistor or compositor, the smell of a burnt transformer but I really don’t know what I’m looking for or where I should be looking.
I’m sure it would be a simple fix for you, I am just at a loss for a fix.
I appreciate your help
Contact Zed Audio to see if they will repair it if you're not interested in troubleshooting (some are not).
Try cutting that transistor out and then measure the resistance from leg 1 to leg 2 on each of the other power supply FETs. If none read near 0 ohms, you may be able to test further without removing any more parts or clamps. If you do this, the remaining FET that was under the clamp with the blown FET needs to be clamped down before applying power.
I'd recommend current limiting in the B+ line. If nothing else, use a 10 amp ATC type fuse.
I'd recommend current limiting in the B+ line. If nothing else, use a 10 amp ATC type fuse.
The ohm 0.2 even the blown one what's left of it ohms 0.2 on the 2 good legs that 1 other leg is burnt off going to put Clamp on and see if powers up? Using 10 amp fuse for safety so I don't blow what's left…
Well put power to it red light was on for sec and nothing….
Can it run without that one ?
Well put power to it red light was on for sec and nothing….
Can it run without that one ?
If all read 0,2 ohms with the known blown one cut out, they all failed (which is common).
Check the output transistors from leg 2-3. Do any read near 0 ohms?
Check the output transistors from leg 2-3. Do any read near 0 ohms?
