Very informative troubleshooting bro, thank you very much. I have the same model, but the issue is , i am not getting the 16 volts supply to the PFC chip and also I get 12 volts only in the cathode of the D37diode when the mains is ON. My question is if I follow your procedure of supplying 18 volts in the cathode D37 and 8 volts to the comparator can i go on with 220 ac mains ON or shall I use 50volts DC input main supply as in your video? Thank you bro.
Hi, NO, you can't supply external supplies with a ground on the diode as shown. When you plug in the mains, it will blow up your power supply. The ground point for the external supply is NOT mains ground / earth. You need to check it as I have shown. The circuits, PFC & SMPS, should draw no more than 50 to 60 mA You should see your circuits are drawing more current or simply just not working.
I've seen broken leads on a Mackie before but i think it was on the old version. Also in powered speakers if you see regulators with small independent heat sinks they often break leads from harmonic resonances causing metal fatigue (if not glued down), Could you have tested those diodes with the mains power on if using a DMM to check for the -&+ on the middle pins, with just the 8v supply connected.
John, is it safe to connect my scope to the direct BASS OUTPUT (both - and +) with the described 50V/3A? I see that you were probing D44 and D43, but I want to be TRIPLE SURE that the amplified signal at CON5 does not ruined my $350USD scope. Thank you for this awesome educational video.
John have you got any video on the detailed working of the PFC section and the way it ties in with the SMP. I have a few problems with units that use this principle but little to none service info …. I could do with some help with..
I've requested $50 for transfer to your PayPal but it will take 3 odd days. Can't do direct transfer from my card to you, bank doesn't allow it. $50AUD = just over 27 quid.
I'm repairing a mackie thump th 18s subwoofer amplifier. They use irs2092 gate driver ic. I checked the pin of the gate mosfet, but there is no pwm signal showed on oscilloscope. Then I tried by turning on without a mosfet, but the irs2092 burned. Have you experienced the same thing? Or do you have any suggestions what should i do? Thanks for replies
@@arisatyabharotoyakti2616 I see. Just thinking aloud, without the fets, various pins will be at the wrong voltage like the middle of the 2 fets. I'd fit a new one with new fets. If it blows or does not work, you have a fake irs chip. Where did you buy the irs chip?
I haven't replaced the gate driver ic yet. It's original from Mackie, that stoped working yesterday. I just removed the mosfet, then the gate driver ic has blows up.
@@JohnB-2021 You said you only had this supply at home and wished you had a bigger one... so I was asking how much is a supply that you would really like?
@@mikeycbd Oh I see, I have no idea and I don't bother looking since I would not be able to afford it anyway lol. Plus, it is rare that I need more than 3 amps.
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Well explained Thanks for the nice video tutorial.
Thank you for your comments
nice work sir
Thank you
Great video, thank you. Did your scope filter the high frequency carrier signal from the output? It looks very clean..
No, I don't think the filter was turned on. (Normal use)
Thank you for your comments.
I guess an isolating trsnsformer will be a good investment for working on smps. At least you can get a small one to power your scope.
I had one years ago and never replaced it. I prefer testing everything with just a low voltage.
Very informative troubleshooting bro, thank you very much. I have the same model, but the issue is , i am not getting the 16 volts supply to the PFC chip and also I get 12 volts
only in the cathode of the D37diode when the mains is ON. My question is if I follow your procedure of supplying 18 volts in the cathode D37 and 8 volts to the comparator can i go on
with 220 ac mains ON or shall I use 50volts DC input main supply as in your video? Thank you bro.
Hi,
NO, you can't supply external supplies with a ground on the diode as shown.
When you plug in the mains, it will blow up your power supply.
The ground point for the external supply is NOT mains ground / earth.
You need to check it as I have shown.
The circuits, PFC & SMPS, should draw no more than 50 to 60 mA
You should see your circuits are drawing more current or simply just not working.
@@JohnB-2021 ok bro, but i need to find another power supply same as yours 5OVdc 3 amps. Then i can proceed. Thanks bro.
@@PowerToneAudio I think if the amp does not start on the mains then another psu is not going to help.
What current is the pfc and smps drawing?
I've seen broken leads on a Mackie before but i think it was on the old version. Also in powered speakers if you see regulators with small independent heat sinks they often break leads from harmonic resonances causing metal fatigue (if not glued down), Could you have tested those diodes with the mains power on if using a DMM to check for the -&+ on the middle pins, with just the 8v supply connected.
Thank you for your input.
Yes, many times I test the +/-75 with mains on if I have a problem somewhere.
John, is it safe to connect my scope to the direct BASS OUTPUT (both - and +) with the described 50V/3A? I see that you were probing D44 and D43, but I want to be TRIPLE SURE that the amplified signal at CON5 does not ruined my $350USD scope. Thank you for this awesome educational video.
You do not need to connect the earth to the speaker ground, connect it to the chassis if the signal in has no ground.
John have you got any video on the detailed working of the PFC section and the way it ties in with the SMP. I have a few problems with units that use this principle but little to none service info …. I could do with some help with..
Hi Steve, no video.
The last pfc was on a Panasonic plasma tv. It’s like the Mackie, just a boost circuit.
Sir..i have mackie srm450v2 avtive speaker..when i turnion on speaker suddenly thermal light stays on any fault in amp??
Hi John, could you assist with getting a Racebox Mini GPS (UART) to connect to a PC running Arcmap (NMEA)?
G'day twin, Is the voltage so high because of the watts? When you talk about voltage of 380 that's almost getting like my car of 400V DC.
Mains voltage is 240 in UK
Multiply by 1.414 will give you the peak voltage of 339 volts.
The PFC coil boost that to 380 volts.
@@JohnB-2021 Yes but why do you need such a high voltage?
@@mikeycbd So as to not distort the mains input and having a large voltage makes the next transformer smaller.
@@JohnB-2021 380V AC? Not DC I never would have known... go tinkering round in that and opps...
@@mikeycbd 380 DC
I've requested $50 for transfer to your PayPal but it will take 3 odd days. Can't do direct transfer from my card to you, bank doesn't allow it. $50AUD = just over 27 quid.
Thank you for your generous donation mikeycbd, it’s the largest donation to date.
Hi John. If is possible to check gate driver ic irs2092 without mosfet?
Yes I imagine it is.
Though Mackie don't use them on this amp.
I'm repairing a mackie thump th 18s subwoofer amplifier. They use irs2092 gate driver ic. I checked the pin of the gate mosfet, but there is no pwm signal showed on oscilloscope. Then I tried by turning on without a mosfet, but the irs2092 burned. Have you experienced the same thing? Or do you have any suggestions what should i do? Thanks for replies
@@arisatyabharotoyakti2616 I see.
Just thinking aloud, without the fets, various pins will be at the wrong voltage like the middle of the 2 fets.
I'd fit a new one with new fets.
If it blows or does not work, you have a fake irs chip.
Where did you buy the irs chip?
I haven't replaced the gate driver ic yet. It's original from Mackie, that stoped working yesterday. I just removed the mosfet, then the gate driver ic has blows up.
@@arisatyabharotoyakti2616 If you watch my sub repairs, the fets always take out the chip or the chips always blow the fets.
You have to change both.
how much is a power supply >3 amps
What voltage?
@@JohnB-2021 You said you only had this supply at home and wished you had a bigger one... so I was asking how much is a supply that you would really like?
2:47 Power supply, you want a bigger one
@@mikeycbd Oh I see, I have no idea and I don't bother looking since I would not be able to afford it anyway lol.
Plus, it is rare that I need more than 3 amps.