I found the mistake.
I have bend the PCB because screw hole are not accurate.
After take out screws for PCB, only left channel gave speaker sounding.
Before it was opposite.
I have bend the PCB because screw hole are not accurate.
After take out screws for PCB, only left channel gave speaker sounding.
Before it was opposite.
You should be able to drill out the pcb mounting holes with a 4mm drill bit.
Hopefully that will allow the pcb to be bolted down without causing bending.
You could stil have a fractured lead to deal with, check carfully and maybe jumper an affected section.
Hi All,
I've been assembling F6 parts for a while, and have been brainstorming about cooling since I wanted to save $ on a full chassis. I had CPU coolers in mind. In reading the posts over the last weeks, the desire for higher bias and the associated heatsink requirements encouraged some more research, and I discovered and pulled the trigger on 4x "DEEPCOOL GAMMAXX 400" heatsinks for the low price of $29CAD each on amazon. Their 4 hole mount should make mounting relatively simple, though I'm still working through exact chassis & mount designs.
I've also been thinking about unique ways to effectively monitor mosfet temp and adjust fan speed, considering both Arduino and Raspi, when I discovered this gem:
QUADRO fan controller for PWM fans
It should allow intelligent fan speed adjustment for each of the 4 mosfets independently, AND use an individually addressable LED strip to display temperature status of each! I'll mount a USB jack for setup/config changes, but otherwise it (apparently) operates independently once programmed. Almost too good to be true!
/Excited nerd rant over
I've been assembling F6 parts for a while, and have been brainstorming about cooling since I wanted to save $ on a full chassis. I had CPU coolers in mind. In reading the posts over the last weeks, the desire for higher bias and the associated heatsink requirements encouraged some more research, and I discovered and pulled the trigger on 4x "DEEPCOOL GAMMAXX 400" heatsinks for the low price of $29CAD each on amazon. Their 4 hole mount should make mounting relatively simple, though I'm still working through exact chassis & mount designs.
I've also been thinking about unique ways to effectively monitor mosfet temp and adjust fan speed, considering both Arduino and Raspi, when I discovered this gem:
QUADRO fan controller for PWM fans
It should allow intelligent fan speed adjustment for each of the 4 mosfets independently, AND use an individually addressable LED strip to display temperature status of each! I'll mount a USB jack for setup/config changes, but otherwise it (apparently) operates independently once programmed. Almost too good to be true!
/Excited nerd rant over
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I had not much time to check last night and I work on week end.
I could check this evening thank you.
I could check this evening thank you.
This is what you need to focus on fixing.
If the leds are on then the issue is most likely incorrect adjustment of trimpots.
I would expect to see voltages across R1 of at least 0.2V, however you should be aiming for around 0.75 V to 0.85 V across R1 ( V R2 should be less due to 0.47 Ohms) which may or may not be achievable with the lower voltage you are obtainig with the leds you have.
If turning the trimpot does not change Vgs of Q1 on right and left channel then maybe you have damaged the wiper on the trimpots (too much heat while soldering).
To me that seems too much of a coincidence that both right and left channel Q1 trimpots are both damaged, although its still possible.
It seems more likely you have turned the trimpots in the complete opposite direction of the way you need to.
It could be powersupply related but you say the leds are on so you should be able to produce voltage at the gates of the mosfets with correct adjustment.
Edit: Please don't connect speakers while doing this.
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I found fail on one of trim pot on left channel witch sound dose not comes out.
Hope only this is the fail.
I have cheapest speakers for testing.
Hope only this is the fail.
I have cheapest speakers for testing.
I have changed trimpot and add one more LED last night.
When I setting bias voltage, I could bias around 0.4V, when I turn for more bias voltage, suddenly light get dark and electric current stops.
Vgs seems same as last time so I am still not solved yet.
I have checked every resistor but nothing problem.
Now I orderd LTL4231N.
When I setting bias voltage, I could bias around 0.4V, when I turn for more bias voltage, suddenly light get dark and electric current stops.
Vgs seems same as last time so I am still not solved yet.
I have checked every resistor but nothing problem.
Now I orderd LTL4231N.
Ok. Check the soldering on the electrolytic capacitors.
Maybe resolder the joints.
If there is any chance you may have damaged them, then replace the capacitors.
At turn on it takes some time for the caps to be fully charged before everything settles down.
Check your signal ground connection back to the psu. Check at both ends.
Maybe resolder the joints.
If there is any chance you may have damaged them, then replace the capacitors.
At turn on it takes some time for the caps to be fully charged before everything settles down.
Check your signal ground connection back to the psu. Check at both ends.
I will check caps and signal ground again.
When I turn bias pot,at the same point around 0.4v
multimeter start on and off.
When I turn bias pot,at the same point around 0.4v
multimeter start on and off.
When you say on off, do you mean the voltage fluctuates back to 0?
The wiper on the trimpot could be bad.
You might have damaged them while soldering.
Are you using Bourns trimpots?
The wiper on the trimpot could be bad.
You might have damaged them while soldering.
Are you using Bourns trimpots?
It seems like the wiper on the trimpot is bad or there is a cold solder joint.
When it goes 0V are the leds still on?
If you cant see any bad joints replace trimpot.
If that doesn't fix it, replace cap.
If that doesn't fix it replace leds.
When it goes 0V are the leds still on?
If you cant see any bad joints replace trimpot.
If that doesn't fix it, replace cap.
If that doesn't fix it replace leds.