# McIntoshC440 boards



## Notloudenuf (Sep 14, 2008)

McIntosh MC440 Power Amplifier Board Complete Many Available | eBay

MC440 boards, no heat sinks that I can tell. Very interesting project for a handy amp person.


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## ATOMICTECH62 (Jan 24, 2009)

He also has MC427 and MC420 boards.


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## TallTexan (Dec 14, 2007)

Sometime ago, someone (Niebur3) was nice enough to send me the MC440 service manual in pdf form. 

Will return the favor for anyone (in need) who PMs me.


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## Notloudenuf (Sep 14, 2008)

What would anyone suggest a person does about a heatsink?

I think the Mac sinks are beautiful, but seeing as how I have no heat sink I have no idea what to do with a board that may or may not need repair...???

Thanks for the hook-up TallTexan. I hope a good EE can get these beauties working.


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## ATOMICTECH62 (Jan 24, 2009)

Mac's are some of the easiest amps to work on.Its almost always the STK pack that goes bad or leaky caps.The Clarion Pro audio's are almost the same amps except for the output transistors and dual power supplies.
Ive bought over a dozen Macs broken and never had to put in more then $20 worth of parts.Some Ive bought had all the right repairs done but they didnt know how to get the power guard and protect lights to stop lighting so they gave up.

Also Mac's have L shaped heatsink rails with holes in them to screw to main heatsink,so if anyone has a case big enough all thats needed is drill holes to secure the board down.


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## TrickyRicky (Apr 5, 2009)

I might pick one up, but would like to see the service manual first to see what am up against, lol.


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## ATOMICTECH62 (Jan 24, 2009)

The picture of the board shows a white plug that has about a dozen wires connected to it.That means this is the M model with the meters.This will make things more complicated.

Those wires are for the meters,lights,bass boost,power guard led and environmental equalizer.So there would need to be some mods done to bypass this plug.The black plug will need jumpers but thats easy.


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## TrickyRicky (Apr 5, 2009)

Yeah when I saw those connections I pretty much said "forget it". I automatically thought the same thing "meters and top-mounted controls perhaps". Without them you wont be able to have a functional amplifier without some serious modifying.


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## ugnlol (Apr 14, 2010)

ATOMICTECH62 said:


> Some Ive bought had all the right repairs done but they didnt know how to get the power guard and protect lights to stop lighting so they gave up.


Would you like to elaborate? 
Just burned a resistor on my mc431 and no the power guard light is on constantly. Replaced but the light is still on..


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## ATOMICTECH62 (Jan 24, 2009)

I would have to know exactly what was replaced on the board before I can help.
Part#,Pics etc...


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## vwdave (Jun 12, 2013)

I saw these boards and thought I might buy just for spare parts or to see what's inside without taking mine apart. These amps will get more and more rare and getting original parts is pretty much impossible now.

Btw, for the Mac gurus, I think my fans are going bad. They are making noise like the bearings are going out. Is this common? Anyone know where to get replacement fans? I can take mine apart to get the specs but it takes effort to remove the amp, then down time to order the fans.


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## ugnlol (Apr 14, 2010)

vwdave said:


> I saw these boards and thought I might buy just for spare parts or to see what's inside without taking mine apart. These amps will get more and more rare and getting original parts is pretty much impossible now.
> 
> Btw, for the Mac gurus, I think my fans are going bad. They are making noise like the bearings are going out. Is this common? Anyone know where to get replacement fans? I can take mine apart to get the specs but it takes effort to remove the amp, then down time to order the fans.


I took my mc431 apart not that long ago and in that it was 2 '40mmx15mm' Sunon fans. 
When I ebay the part number they where still available.. but a litle more costly than others. But the fans in the mcintosh amps have a special kind of connector, so maybe you need to use the connectors from the old fan to connect it to the board.


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## vwdave (Jun 12, 2013)

ugnlol said:


> I took my mc431 apart not that long ago and in that it was 2 '40mmx15mm' Sunon fans.
> When I ebay the part number they where still available.. but a litle more costly than others. But the fans in the mcintosh amps have a special kind of connector, so maybe you need to use the connectors from the old fan to connect it to the board.


Thank you so much. I almost always have to solder on the original connectors when it comes to replacement fans.


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## ATOMICTECH62 (Jan 24, 2009)

Most fans have a C clip holding the fan shaft in place.I have taken them apart and cleaned the **** out,lubed them up and they work fine.


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## vwdave (Jun 12, 2013)

Ok maybe I will try that when I get a chance.

I was debating recapping the amp while I am in there...not sure it's worth it since the amp works fine.


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## ATOMICTECH62 (Jan 24, 2009)

These have the clips under the Sunun sticker.


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## gcha006 (Oct 17, 2013)

TallTexan said:


> Sometime ago, someone (Niebur3) was nice enough to send me the MC440 service manual in pdf form.
> 
> Will return the favor for anyone (in need) who PMs me.


Hi could you please email to me at [email protected]

thanks


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