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Marantz 2238 (not B) Rebuild questions

Wire Nut

Wire Nut

Active Member
Hi, I just bought a real clean 2238 and have installed 5 way binding posts and replaced the taltium caps and want to move on to other boards and follow the directions from the parts I got from Peace, love, and music - he sold me everything but the caps as I have boxes of them. I mostly use Panasonic for the non audio caps.
My question is how to get the power board out, the front is straight forward as there is a screw in each corner but even if I take those out it would not come out because of the transistors on the back of the board. Would I just pull those out to get the whole board out?

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To rebuild the board you'll remove the heat sink. No wires need to be removed to rebuild this board, you just need to get the heat sink out of the way. As you noted there are the four screws at the corners of the circuit board. There may be one or two additional ones in the center of the board...sorry I don't have pictures to confirm for this model, it may just be the four corners. Remove the output transistors.

The two bias diodes are held in clips behind the output transistors. See the pictures. They can be a PITA to get back into correct positions. Get better pictures than mine that show how they are installed for when you put it back together. And, the leads on the bias diodes are do not take well to being bent back and forth. Take care while they are hanging loose to not bend them around.

Once the transistors are out and the bias diodes are clear of the heat sink then you can remove the 4 screws holding the heat sink to the chassis and lift it out. Note that it is easier to rebuild the with the filter capacitors removed but it is not essential to do so. It just gives more room to work.

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Ah, I see the truth of it! I will give it a try. Right now I have the tone board out and just pulled the first caps and see they are bipolar and I don't have that value so will need to order some. It will be a few days until I can get to the power board but thanks a million guys.
 
So it is simple just unscrew the bottom screws on 1813 and 1814 to detach the board and heatsink from the chassis then unscrew the 1815 screws to remove the heat sink- best remove the output transistors first :) another question to follow
No need to unscrew the 4 front screws!
 
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I got it all recapped and am ready to do the settings for DB & Bias... I can't find the posts for attaching the multimeter. J's 722, 723, 724 - 714, 715, 716, & 717. Can anyone point me to where they are?
 
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You can't find J722-724? You think J727 is J724? J723 and J724 are the relay channel ouputs and J722 is ground.
 
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I replaced all of the "fuse type" lamps with LED's but my channel needle lamp is out, can anyone tell me what bulb I need to get to replace it?
Thanks!
 
Normally will now put a small LED with a resistor on one of the wires. A 330 Ohm 1/4 Watt should work fine.

Then will flatten the dome with a file on the LED to help with defusing the light.
 
I got the lamps and resistors- thanks for the advice! I have a sample pack of over 100 colors of stage lighting gel and picked a dark amber to wrap the bulb in, it looks great- not just the normal white. (that is not your daddies AR-XA)
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