Mosfet irf9530

[Bret burrill]

I'm new to this and trying to make a repair to a pioneer plate amp. The mosfets I need to replace are irf9530 other info printed on them y37k a0

is the other info a batch number? I have found that all irf9530's are not the same. How do I go about buying suitable ones?

IRF9530PBF Vishay / Siliconix | Mouser

IRF9530NPBF Infineon / IR | Mouser

 

[aparatusonitus]

You have to buy IRF9530 or IRF9530PBF, it's the very same mosfet, the 2d one is lead free (thats what suffix PBF stands for)...so no N, L or any other letter behind nambers except PBF.

 

[Bret burrill]

Thank you that is helpful.

 

[aparatusonitus]

Check the mosfet drivers also (probably some BJT transistors in TO-92 or TO126 housing)...they usually go puff along the main output devices!

 

[Bret burrill]

Can you describe what they might look like. I looked up all the chips I can see and they are op amps an one on amp. There are two units in the center of the board that look a lot like the mosfets but I can't see what is printed on them.

 

[aparatusonitus]

Could you tell as a full model no of Pioneer plate amp so I can see if I can find service manual or schematic for that model?

 

[Bret burrill]

Yes. Pioneer sw-8mk2

I started a thread in 'solid state' on this, but jumped over here to ask about ordering parts.

 

[aparatusonitus]

I couldn't´t locate schematic or service manual so you will be forced to dismantle plate amp and take pictures so we can see what are we dealing with.

 

[Bret burrill]

OK. There is a lot of black stuff where it meets the plate. I'll have to see if I can separate it.

 

[Bret burrill]

Here are some photos. I don't know how to pull this board off the plate. I tried cutting the black adhesive material with a hobby knife. I suppose I will have to separate it to get better pictures.

 

[aparatusonitus]

What we want to see is the pcb area behind those big black filter capacitors… upper right corner of the pcb. You will probably see IRF530/IRF9530 output mosfets there with lots of smd devices in front. Be careful with knife...that black adhesive material is really pain the *** to remove...don´t brake anything.

 

[Bret burrill]

The only things back there are in r107 and r108

the printing on them is 3321 and 32r1. I think. They are very small.

I believe 3321 is a thin film resistor and 32r1 is a current sense resistor

 

[aparatusonitus]

The rest of the amplifier has to be somewhere...take a look from underside of psb.

 

[Bret burrill]

Like this?

 

[aparatusonitus]

Yes...it seems the entire amplifer is on the top of the pcb...see if you can see any burn components.

 

[Bret burrill]

Nothing is burned. Maybe swap out the mosftes and see what happens?

 

[aparatusonitus]

NOPE!!! Build a dim bulb tester first...very useful test equipment which enables you to look for power shorts in a non-destructive fashion. See on YouTube how to build one.

 

[Bret burrill]

Do you recommend the bulb tester over a multimeter?

 

[aparatusonitus]

You need both, 60-100W incandescent bulb tester will prevent further damage if something else is broken other then output mosfet, you will need multimeter to check output DC offset (less then 50mV DC) and amplifier idling current (50-100mA probably).
https://www.antiqueradio.org/art/DimbulbSketch.jpg

 

[Bret burrill]

OK. Thank you very much for the information. I'm enjoying this.