Swapping phono boards in 22xx???

[viapol]

OK, so I have a non working phono board in a 2250.
I've heard the 2230 has a good phono stage in it.
Could a person use the 2230 board in the 2250?
Second question.. does anyone know if the phono boards are the same for 2250 and 2250b?

 

[bryans12v]

I would just fix the one you have. They're basically identical if I'm not mistaken. Nothing to gain.

 

[KutzlerTrans]

If its busted beyond repair, then compare part numbers as found in the service manuals.

Remember, there are issues with two transistors on these older units and you may be jumping from the pot to the fire if you don't check the numbers first and upgrade them.
The bad ones are the 2sc458. Use KSC1845 in their place.

 

[viapol]

Thanks for the advice and the advice on the transistors. I will attempt to replace them. I am still trying to learn this stuff...pnp..npn..ohms..Volts...Etc.

 

[viapol]

Well I visually checked the transistors. They are c1344- there are 6 on the phono board. Is there n easy way to check them? I have a multimeter.

Can you check them still being soldered to the board or do they have to be out?

 

[Steven Tate]

The phono board on a 2250 usually has four 2SC1344 transistors and two 2SC458's. Are you sure all six are the same transistor? As far as checking them, you need a DMM with a diode test function. They need to be removed from the board and then follow the instruction in Echowar's post on testing transistors here: (Or just replace them with suitable substitutes, which is usually best since you are going to the trouble of taking them off the board)

http://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/

 

[viapol]

Found the 2 sc458s on the board. I'll replace and see where I'm at. Thanks alot!

 

[bryans12v]

If your not in too much of a hurry, I can post them to you along with some new diodes to replace those vd1212 varistors. I have more than I will ever use.

 

[viapol]

I'm in no hurry, I got the transistors out. I practiced soldering and desoldering on a junk board for about 2 hrs before i touched the marantz. I can flip ya back some $ for postage if you wouldnt mind sending those. This is actually kinda fun. I can see now why recapping to some people isn't that big of a deal... I hope these transistors were my problem. My phono stage was super quiet. Barely hear at 1/4, audible from 10 ft at 1/2 volume.