Looking for a service manual for 2245.

[Klownschool]

I just picked up a 2245 at a rummage sale and would like to begin working on it as soon as I can. I would greatly appreciate it if someone could send one my way or point me to a pdf.

http://audiokarma.org/forums/showthread.php?t=106822

Thanks in advance,
Rick

 

[Cuthbert]

IIRC, I saw a post that the 2270 was about identical to the 2245 and a 2270 pdf sm is available at:
http://www.hifiengine.com/library_model.php?make=Marantz&selected_model=2270
I have DL'ed it cuz I need to correct the dc offset in my 2245 but have not gotten around to it yet.
You may want to verify this first as it has been a couple of weeks since I saw the post.

 

[Klownschool]

Thanks Cuthbert, it was still posted. How close to identical are they? I guess I am really just looking to do the bias and dc offset so as long as that info is correct I should be good to go.

Rick

 

[merrylander]

If all you want to do is set DC offset and Idle current you don't need the SM because it has a misprint in the idle adjustment. Here is the scoop;

DC Voltage adjustment: Put a meter across pins J802 and J803 on the regulator board and adjust the variable resistor R809 for 35V

DC Offset adjustment: Connect a DC meter between the speaker terminals and adjust the variable resistor R762 for a 0V reading. R762 is the one closest to the edge of the circuit boards.

Idle current adjustment: Connect a DC meter between pin terminals J760 and J754 and adjust the variable resistor R763 fully counter clockwise then turn it clockwise until you get a 5 millivolt reading. R763 is the one in the middle.

Note: The manual says pins J753 and J754 but all you will read between those pins is 35V and turning R763 will not change that.

 

[Cuthbert]

If all you want to do is set DC offset and Idle current you don't need the SM because it has a misprint in the idle adjustment. Here is the scoop;

DC Voltage adjustment: Put a meter across pins J802 and J803 on the regulator board and adjust the variable resistor R809 for 35V

DC Offset adjustment: Connect a DC meter between the speaker terminals and adjust the variable resistor R762 for a 0V reading. R762 is the one closest to the edge of the circuit boards.

Idle current adjustment: Connect a DC meter between pin terminals J760 and J754 and adjust the variable resistor R763 fully counter clockwise then turn it clockwise until you get a 5 millivolt reading. R763 is the one in the middle.

Note: The manual says pins J753 and J754 but all you will read between those pins is 35V and turning R763 will not change that.

Thanks Merrylander for this information, I was getting ready to adjust mine also based on the directions in the 2270 SM.
Is this misprint in the 2245 SM and the 2270 SM?

EDIT:
One other question please, in the 2270 SM IIRC there are dc offset adjustments for each channel L/R on the 2270 so does this apply to the 2245? Or maybe I misread.

Thank you for your help

 

[merrylander]

I don't have a 2270 manual so I can't say, but the 2245 manual is definitely wrong

 

[Klownschool]

Thanks a ton Merrylander. Let me know how to get on the list for cabinet restoration. I hear you are the master!

Rick

 

[yo00]

2250b

hello, this procedure applies to the 2250b model too? any advice will be apreciated. thank you in advance.

 

[Cuthbert]

The 2270SM may be in error also as it shows for idle current adjustment to connect meter to J753 and J754. But J753 is scratched out and whoever scanned this manual for hifiengine penciled in J756 which may be correct for the 2270. The other adjustments seem to match what merrylander has posted.
Glad you looked at this thread merrylander. Thanks again.

 

[whsh93a]

The 2270 manual is wrong the same way. You can almost see where the "2270" numbers were cut and pasted over the "2245" numbers.

DH

I don't have a 2270 manual so I can't say, but the 2245 manual is definitely wrong

 

[RocknRum]

Actually reading a post of Echowars, he stated for idle current adjustment, J754 and J760 and set it for 10mv. Not 5mv as it states in the manual.


Someone asked about the 2250B. The manual states for voltage adjustment,
place meter leads at terminals 804 and 805 and adjust R806 for 35V DC.

DC offset - connect leads between speaker terminals and adjust R707 for 0V DC.
Idle current adjustment - connect meter between terminals 708 and 710. Adjust trimmer R719 for 10V DC. After setting, check DC offset again and adjust if necessary. This manual is correct for these adjustments.

 

[yo00]

2250b

thank you very much, about your guide, i will try hard to do the best i can for my trusty marantz, thanks again. best regards. :yes:

 

[Cuthbert]

Thanks to echowars and merrylander I was able to get my 2245 Offset, DC voltage and idle current back to spec. It sounds real purty now. Thanks for your help.:yes: