Hello fellow diyaudio members i have in a ampere 2000.1D when i got it. It had some vibration damage snaped legs on output fets causes the power supply to short and fail. This amp has the dwm1216 output driver board a seen in perrys class d type 8 notes and i believe it is the same as tbe sundown saz.v1.1500 board.
So got tbe power supply up and going all waveforms look great i check for all voltages before moving on to output side and they are all present -5v.+5v, -15v.+15v, -12v.+12v all present and with output fet out of the board i have a waveform on tbe gate,source legs of positive rail and negative rail so i put the outputfets in and tbe amp trys to come on it powers on blue light and before relay engages tbe power light starts to flash off and on no protection light just the power led flashing off and on and the 4 test mosfet in the out of the amp heat up quickly and will fail if left cycling. If i take driver board out the amp powers on relay engages fine and ive read over type 8 class d trying to figure it out also taking out components to see if it will power on fully but to no avail i did notice if i took out tbe 5v regulators the amp powers up with driver board in and output mosfets stay cool and im at the point were what knowledge i have isnt doing it and i keep going back the perrys guide trying numerous things but the amp will not cooperate. Any help would be great appreciated pics below of board!
So got tbe power supply up and going all waveforms look great i check for all voltages before moving on to output side and they are all present -5v.+5v, -15v.+15v, -12v.+12v all present and with output fet out of the board i have a waveform on tbe gate,source legs of positive rail and negative rail so i put the outputfets in and tbe amp trys to come on it powers on blue light and before relay engages tbe power light starts to flash off and on no protection light just the power led flashing off and on and the 4 test mosfet in the out of the amp heat up quickly and will fail if left cycling. If i take driver board out the amp powers on relay engages fine and ive read over type 8 class d trying to figure it out also taking out components to see if it will power on fully but to no avail i did notice if i took out tbe 5v regulators the amp powers up with driver board in and output mosfets stay cool and im at the point were what knowledge i have isnt doing it and i keep going back the perrys guide trying numerous things but the amp will not cooperate. Any help would be great appreciated pics below of board!
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Did you replace Q7, 11, 19, and 22 across the top of the board and confirm that all of the 470 ohm resistors in that area are within tolerance?
As of now, are the outputs in or out of the board?
As of now, are the outputs in or out of the board?
Yes i replaced Q7, 11, 19, and 22 across the top of the board. The 470 ohm resistors seem to all check out however should i have to lift them to be for sure or is it ok that i left them on to check?
The output fets are in at this moment.
The output fets are in at this moment.
Solder a bridge between the collector and emitter of Q8. Does the amp stay on?
You don't need to do any more on the 470 ohm resistors at this point.
You don't need to do any more on the 470 ohm resistors at this point.
With the bridge soldered from collector to emitter on q8 as soon as the power light goes to lite it goes into protection.
Assuming I did the test right black Probe on amp main ground red probe on the output of the filter inductor windings. When amp is powered up I get 50 millivolts and when amp goes in protect it goes away
I was hoping that you would see something more significant.
Remove the resistor R31 (4.7 ohms). That will prevent the main board from going into protect (assuming that the fault is in the output section).
Then re-check for DC.
Be careful. This will defeat part of the protection circuit.
Also, don't leave it on for significantly longer than necessary. The driver board is driving the driver circuit into protection mode which is hard on the 470 ohm resistors.
Remove the resistor R31 (4.7 ohms). That will prevent the main board from going into protect (assuming that the fault is in the output section).
Then re-check for DC.
Be careful. This will defeat part of the protection circuit.
Also, don't leave it on for significantly longer than necessary. The driver board is driving the driver circuit into protection mode which is hard on the 470 ohm resistors.
Ok Perry with r31 removed and Q8 still bridged it does power up with no protect an I get a DC voltage upon power on it jumps sometimes to 2.03vdc sometimes 1.78vdc its never the same really but when i let off remote the voltage jumps up to -3/-2 vdc always goes negative when remote is let off and then counts down til nothing.
If you connect a load to the speaker terminals, do you see any DC across the speaker terminals (I'm assuming that the relay is engaging)?
I wasn't leaving it on long so idk if the relay is engaging i was hitting the foot pedal for the remote and when it would go to power on as soon as i got the dc voltage i would let off. However i will leave it on longer to see if it will engage an if so perform the test and get back to you perry.
Ok perry after testing again this time leaving the amp on longer until relay engages i get a plus of dc voltage on tbe inductor and after the relay engages it stays at 0.070vdc.
With a 30 ohm 5 watt resostor across the speaker terminals i get 0vdc across speaker terminals on power on and after relay engages.
With a 30 ohm 5 watt resostor across the speaker terminals i get 0vdc across speaker terminals on power on and after relay engages.
OK. The problem appears to be on the driver board.
When you checked for drive signals on the output FETs, what did you find there?
When you checked for drive signals on the output FETs, what did you find there?
Before the previous mods to the driver board when the output fets were in the board i would get the correct rail voltages on the gate and source legs for both positive and negative outputs but on the drain legs of the positive and negative outputs on power up you would see a waveform start to build then go away and it would repeat that at the same pace and time the power light was flashing.
Would like me to see what is there now?
Would like me to see what is there now?
There won't be any drive on the outputs so nothing on the drains.
What do you see on terminal 15 of the driver board if you drive a 50-100Hz drive signal into the amp?
What do you see on terminal 15 of the driver board if you drive a 50-100Hz drive signal into the amp?
R24 reads 180 ohms.
Idk if it will help but i put another driver board in that if i remember correctly worked in the amp it was in and it did the same thing power light would flash off and on.
I have a hifonics bre2500.1 that is very close to this design same output section same number of outputs i can try and use the bare minimum to get it up and going to see if it is this driver board or something on the main if that would be helpful
Idk if it will help but i put another driver board in that if i remember correctly worked in the amp it was in and it did the same thing power light would flash off and on.
I have a hifonics bre2500.1 that is very close to this design same output section same number of outputs i can try and use the bare minimum to get it up and going to see if it is this driver board or something on the main if that would be helpful