I went with 2 4ohm dummy load hooked up in parallel to get 2ohms.
Power supply was set on 12v 10amps.
Results: FETs, 494 and 319 got around 98 degrees Fahrenheit.
Amps jumped back and forth from .140 to .700.
Voltage stayed at 12v
LED's back and forth from blue (on) to red (protect)
Power supply was set on 12v 10amps.
Results: FETs, 494 and 319 got around 98 degrees Fahrenheit.
Amps jumped back and forth from .140 to .700.
Voltage stayed at 12v
LED's back and forth from blue (on) to red (protect)
319? Are you referring to the one on the audio driver board? If so, did the other ICs on that board reach the same temperature?
DCV on the supply terminals (6 and 11) of the 319?
There's no reason for the 494 to heat up.
How low was the voltage dropping at the amp's terminals?
Did all FETs heat up evenly?
Were the FETs on any sort of heatsink?
DCV on the supply terminals (6 and 11) of the 319?
There's no reason for the 494 to heat up.
How low was the voltage dropping at the amp's terminals?
Did all FETs heat up evenly?
Were the FETs on any sort of heatsink?
Sorry, I had to put this amplifier away because I got to a dead end and wanted to take a little break.
Q: 319? Are you referring to the one on the audio driver board? If so, did the other ICs on that board reach the same temperature?
A: Yes the 319 on the audio riser card. No other ICs got hot.
Q: DCV on the supply terminals (6 and 11) of the 319?
A: DVC on the 319 = I tried to get the reading but the amps shot up to 5.5 amps so I turned it off.
Now if I have just the irf3205 power supply side FETs in everything works great.
I checked everything on the rectifier pads and all is good but when I install the rectifiers it blows 1 irf3205, just 1 and goes into protect. (no smoke or sound)
Q: How low was the voltage dropping at the amp's terminals?
A: Before it starting blowing the irf3205 the voltage on the amp's terminals did not drop.
Q: Did all FETs heat up evenly?
A: All the FETs heated up all evenly.
Q: Were the FETs on any sort of heatsink?
A: Yes the board was back in the case with the irf3205 clamped down.
Q: 319? Are you referring to the one on the audio driver board? If so, did the other ICs on that board reach the same temperature?
A: Yes the 319 on the audio riser card. No other ICs got hot.
Q: DCV on the supply terminals (6 and 11) of the 319?
A: DVC on the 319 = I tried to get the reading but the amps shot up to 5.5 amps so I turned it off.
Now if I have just the irf3205 power supply side FETs in everything works great.
I checked everything on the rectifier pads and all is good but when I install the rectifiers it blows 1 irf3205, just 1 and goes into protect. (no smoke or sound)
Q: How low was the voltage dropping at the amp's terminals?
A: Before it starting blowing the irf3205 the voltage on the amp's terminals did not drop.
Q: Did all FETs heat up evenly?
A: All the FETs heated up all evenly.
Q: Were the FETs on any sort of heatsink?
A: Yes the board was back in the case with the irf3205 clamped down.
Are you saying that it's blowing a 3205 while clamped tightly to the heatsink and with the resistor inline?
Is the same 3205 location blowing every time?
Lift the supply terminals of the 319 and see if anything changes.
Is the same 3205 location blowing every time?
Lift the supply terminals of the 319 and see if anything changes.
Q: Are you saying that it's blowing a 3205 while clamped tightly to the heatsink and with the resistor inline?
A: Yes
Q: Is the same 3205 location blowing every time?
A: Yes, power supply side 6th FET down.
Q: Lift the supply terminals of the 319 and see if anything changes.
A: How would I do that? It's a SMD, should I remove it, lift pin 11 then solder it back except pin 11?
After removing rectifiers and bad FET all is good on power supply side (green led)
A: Yes
Q: Is the same 3205 location blowing every time?
A: Yes, power supply side 6th FET down.
Q: Lift the supply terminals of the 319 and see if anything changes.
A: How would I do that? It's a SMD, should I remove it, lift pin 11 then solder it back except pin 11?
After removing rectifiers and bad FET all is good on power supply side (green led)
Did the 3205s come from a reputable source? The limiter won't allow more than 7A (2 ohm limiter) and the heatsink won't allow the FET to heat up if the FET is mated properly to the sink.
Is there any voltage of any type on the heatsink?
Use a small jeweler's screwdriver to lift the terminals (6 and 11) while heating their solder.
Is there any voltage of any type on the heatsink?
Use a small jeweler's screwdriver to lift the terminals (6 and 11) while heating their solder.
I had to put away this board because I was about to drop kick it in the trash.
Q: Did the 3205s come from a reputable source?
A: Yes I get most all parts from Mouser.
Q: Is there any voltage of any type on the heatsink?
A: No voltage on heatsink.
I removed the card with the 319 on it and it does the exact thing.
If I remove the rectifiers, power supply works great and stays cool.
Q: Did the 3205s come from a reputable source?
A: Yes I get most all parts from Mouser.
Q: Is there any voltage of any type on the heatsink?
A: No voltage on heatsink.
I removed the card with the 319 on it and it does the exact thing.
If I remove the rectifiers, power supply works great and stays cool.
Could a rectifier be in the wrong place?
Could a rail capacitor be installed backwards or shorted?
Are the output FETs in the circuit?
Could a rail capacitor be installed backwards or shorted?
Are the output FETs in the circuit?
Q: Could a rectifier be in the wrong place?
A: I wrote them down but I might have got them reversed. ( I suffer from CRS. (can't remember ****)
I tried looking the board up to see the correct location but cannot find anything.
Q: Could a rail capacitor be installed backwards or shorted?
A: All capacitor are correct and no shorts.
Q: Are the output FETs in the circuit?
A: No output FETs are installed.
A: I wrote them down but I might have got them reversed. ( I suffer from CRS. (can't remember ****)
I tried looking the board up to see the correct location but cannot find anything.
Q: Could a rail capacitor be installed backwards or shorted?
A: All capacitor are correct and no shorts.
Q: Are the output FETs in the circuit?
A: No output FETs are installed.
When you get old, you won't remember not being able to remember things that you can't remember now.
Does it use all positive rectifiers or does it use a mix of rectifiers (CT, CTR)?
Does it use all positive rectifiers or does it use a mix of rectifiers (CT, CTR)?
Q: Does it use all positive rectifiers or does it use a mix of rectifiers (CT, CTR)?
A: 4 CT and 4 CTR.
A: 4 CT and 4 CTR.
It goes from the power supply side same on both sides CT CT CTR CTR it doesn't have markings/Numbers .
Confirm that the center terminal of the CTs go to positive rail cap terminals and the center terminals of the CTRs go to the negative rail cap terminals.
Did you check all rectifiers to confirm that none were leaking or shorted?
Did you check all rectifiers to confirm that none were leaking or shorted?
Yes it does have markings. Q21 CT, Q22 CT, Q23 CTR, Q24 CTR, other side Q9 CT, Q10 CT, Q11 CTR, Q12 CTR.
Did you notice any rectifiers heating when they were installed?
Without the rectifiers, do you have a 50% duty cycle square wave of 10v amplitude on all of the PS FET gate legs?
Without the rectifiers, do you have a 50% duty cycle square wave of 10v amplitude on all of the PS FET gate legs?
Q: Confirm that the center terminal of the CTs go to positive rail cap terminals and the center terminals of the CTRs go to the negative rail cap terminals.
A: CT to positive rail = cap charging. CTR to negative rail = holding at 42 ohms.
Q: Did you check all rectifiers to confirm that none were leaking or shorted?
A: Yes, I check everything with a MK-328 tester before install.
Q: Did you notice any rectifiers heating when they were installed?
A: Not heating but I cut power within 5 to 10 seconds when voltage drops and 4amps draw ( I set my power supply to 10v 4a)
Q: Without the rectifiers, do you have a 50% duty cycle square wave of 10v amplitude on all of the PS FET gate legs?
A: I do believe so. Without rectifiers I probed all FETs and it was perfect like all other working amps I have.
If you think I should remove the rectifiers and test to make sure let me know.
A: CT to positive rail = cap charging. CTR to negative rail = holding at 42 ohms.
Q: Did you check all rectifiers to confirm that none were leaking or shorted?
A: Yes, I check everything with a MK-328 tester before install.
Q: Did you notice any rectifiers heating when they were installed?
A: Not heating but I cut power within 5 to 10 seconds when voltage drops and 4amps draw ( I set my power supply to 10v 4a)
Q: Without the rectifiers, do you have a 50% duty cycle square wave of 10v amplitude on all of the PS FET gate legs?
A: I do believe so. Without rectifiers I probed all FETs and it was perfect like all other working amps I have.
If you think I should remove the rectifiers and test to make sure let me know.
After removing every connection from the amp...
For the low side, I'd connect a current-limited supply across one of the negative rail caps (with the correct polarity) to see if anything heats up.
How much current does it try to draw?
For the low side, I'd connect a current-limited supply across one of the negative rail caps (with the correct polarity) to see if anything heats up.
How much current does it try to draw?
Q: How much current does it try to draw?
A: I have it set on 4a and it will start pulling .460 then within seconds it will jump and pull all 4a
I had it set on 10a and it jumped to 10a but kept blowing 3205s. Its like a dead short but I tested everything and didn't find any shorts.
I will connect a current-limited supply across one of the negative rail caps and give you the results but give me some time, i'm taking my dad to lunch.
Thanks for the time trying to figure this mess out.
A: I have it set on 4a and it will start pulling .460 then within seconds it will jump and pull all 4a
I had it set on 10a and it jumped to 10a but kept blowing 3205s. Its like a dead short but I tested everything and didn't find any shorts.
I will connect a current-limited supply across one of the negative rail caps and give you the results but give me some time, i'm taking my dad to lunch.
Thanks for the time trying to figure this mess out.