Phonic Powerpod 740 problems
Hi everyone,
I've managed to repair my 740 with the assistance of the contributor ( ShorBird ) who posted the repair kit details. He was able to mail me the schematics of a similar model.
In the end, I worked through the circuit and replaced everything that had blown - not just the bits in the kit...
I took all the transistors and diodes out and tested them separately - then I replaced the ones which tested OK to be sure...
I still have no idea what caused the problem - the circuit seems to be a reasonable design and has all the obvious protection in place, etc.
I had to replace the following parts:-
The pair of IGBT switchers
The four driver transistors
( 100Volt 1 watt TO-92 - 2 NPN & 2 PNP )
The four transistors in the PWM feedback loop
( 60 Volt 300mW TO-92 - 2 NPN & 2 PNP )
The 15 volt regulator on the startup supply ( 7815 )
Plus all the diodes in the kit
All the small transistors are hard to get, but if you look for the data sheets on the web, they aren't anything special.
I replaced them all with generic parts which I could buy easily
I confused myself by looking for DC on the output fuses before realising that they are in the AC lines from the transformer...
Total cost of the parts was about £10 and the unit is now 100% OK.
Hi everyone,
I've managed to repair my 740 with the assistance of the contributor ( ShorBird ) who posted the repair kit details. He was able to mail me the schematics of a similar model.
In the end, I worked through the circuit and replaced everything that had blown - not just the bits in the kit...
I took all the transistors and diodes out and tested them separately - then I replaced the ones which tested OK to be sure...
I still have no idea what caused the problem - the circuit seems to be a reasonable design and has all the obvious protection in place, etc.
I had to replace the following parts:-
The pair of IGBT switchers
The four driver transistors
( 100Volt 1 watt TO-92 - 2 NPN & 2 PNP )
The four transistors in the PWM feedback loop
( 60 Volt 300mW TO-92 - 2 NPN & 2 PNP )
The 15 volt regulator on the startup supply ( 7815 )
Plus all the diodes in the kit
All the small transistors are hard to get, but if you look for the data sheets on the web, they aren't anything special.
I replaced them all with generic parts which I could buy easily
I confused myself by looking for DC on the output fuses before realising that they are in the AC lines from the transformer...
Total cost of the parts was about £10 and the unit is now 100% OK.
Hello there,
Could you send the parts "System Block Diagram" and "Digital Effect Schematic" of the Powerpod 740 Mixer Service Manual to wplco@lykamspam.pl? There is a problem with DSP and an electrician wants the schematics to repair it.
Regards, DJ TrueBeliever.
Could you send the parts "System Block Diagram" and "Digital Effect Schematic" of the Powerpod 740 Mixer Service Manual to wplco@lykamspam.pl? There is a problem with DSP and an electrician wants the schematics to repair it.
Regards, DJ TrueBeliever.
Could you repair the amp and what is the most likely cause of the blown smps?
I have an similar problem