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Marantz 2238b recapping any tips?

sruddy

sruddy

Super Member
Hi all,
I have my Dad’s old Marantz 2238b receiver and would like to start using it. I have no idea if it’s ever been serviced but one of the channels is lower so the balance needs to be thrown off to equalize it. I have found all the manuals and schematic at Hi Fi engine. Does anyone have any tips or info for me before I start buying parts? Thanks very much.
Steve
 
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The first thing to do any time you are working on a model for the first time is go to the Marantz Service Manual Error Thread near the top of the Marantz forum. While in that thread, do a search on the model number, like 2238b, click the "Search this thread only" box, and do the search. The 2238b has many errors listed. They can save you a lot of time and heartache if you know about them ahead of time.
 
Steven Tate said:
The first thing to do any time you are working on a model for the first time is go to the Marantz Service Manual Error Thread near the top of the Marantz forum. While in that thread, do a search on the model number, like 2238b, click the "Search this thread only" box, and do the search. The 2238b has many errors listed. They can save you a lot of time and heartache if you know about them ahead of time.
Click to expand...

Thank you, I found this YouTube video
It’s of a unit were the assembly glue damaged components. I have experienced this with a Sansui amp and it was no fun restoring. I hope I don’t find it in this unit. I’m also considering buying a kit from hi fi audio but it’s $165! It would save me a bunch of time ordering myself and they are saying they use very good and proper parts. I would have to research which caps need to be ESR or some other spec other than the values too so I’m considering it. I haven’t run across any rebuild threads here that may have some good info. I’ll search YouTube.
 
I would also recommend to be very careful with any eBay rebuild kit, or avoid it altogether.

Randy/Runningdog, from iRebuildMarantz.com, doesn't have a 2238/B kit listed on his site, or I would highly recommend that, have used four of them, and they're top notch.

The AK Database has your 2238B Owner's Manual, and Service Manual, which sometimes is different than the others found on the web:
http://akdatabase.com/AKview/thumbnails.php?album=1&page=4

The Service Manual has the parts list for every board in your 2238B, the electrolytic's are what you'll be looking to replace, and possibly some diodes and transistors.

If you're serious about doing this yourself, the Hakko FR-301 desoldering gun can make this project easy, and fun - if you're that type.
 
David Whalen said:
Be patient and let the experienced people here guide you. Do not buy that cap kit on the bay. It is a waste of money.
Click to expand...

Ok thanks!

MarantzRefrb said:
I would also recommend to be very careful with any eBay rebuild kit, or avoid it altogether.

Randy/Runningdog, from iRebuildMarantz.com, doesn't have a 2238/B kit listed on his site, or I would highly recommend that, have used four of them, and they're top notch.

The AK Database has your 2238B Owner's Manual, and Service Manual, which sometimes is different than the others found on the web:
http://akdatabase.com/AKview/thumbnails.php?album=1&page=4

The Service Manual has the parts list for every board in your 2238B, the electrolytic's are what you'll be looking to replace, and possibly some diodes and transistors.

If you're serious about doing this yourself, the Hakko FR-301 desoldering gun can make this project easy, and fun - if you're that type.
Click to expand...

Thanks for the info, I would love to have the desolder tool! I have been using de solder tap and or an old rubber bulb squeeze type that I think I got 20 years ago at Radio Shack. At least I have a Hakko FX951-66
soldering gun.
 
I ordered all the electrolytic caps for the power, amp, and tone boards. While I’m waiting I thought I would test the power supply voltage. It was at 20vdc and The pot bottomed out at 26vdc, should be 35! I think there is a problem, and don’t know if the filter caps will fix it.

looks like service manual had wrong info. I didn’t see it noted in the wrong sticky. They indicated wrong PIN numbers right pins are J722 (+) and J728 (-),
 
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Never need to work on a 2238B have on a 2252B.

Getting the main board out is a little tricky. The Main filter caps need to be moved up and out of the way. They hold a charge so be very careful. Getting to the screws are a real PITA!
 
MarantzRefrb said:
I would also recommend to be very careful with any eBay rebuild kit, or avoid it altogether.

Randy/Runningdog, from iRebuildMarantz.com, doesn't have a 2238/B kit listed on his site, or I would highly recommend that, have used four of them, and they're top notch.

The AK Database has your 2238B Owner's Manual, and Service Manual, which sometimes is different than the others found on the web:
http://akdatabase.com/AKview/thumbnails.php?album=1&page=4

The Service Manual has the parts list for every board in your 2238B, the electrolytic's are what you'll be looking to replace, and possibly some diodes and transistors.

If you're serious about doing this yourself, the Hakko FR-301 desoldering gun can make this project easy, and fun - if you're that type.
Click to expand...

I ended up biting the bullet and buying the Hakko desoldering gun. There are apparently lots of expensive tips for it but only one is included. Which tip would be the best for using on the Marantz?
 
Looks like you bought the 200 receivers size of 5 ounces. Since you smear that stuff on as thin as possible on both sides of the mica insulator as it is only there to fill in the gaps between the mica and metal, you will have plenty for your next 199 projects.

Should be a video on how to use thermal paste on the web.
 
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Looks Like I f'd up something already! I replaced all the electrolytic caps on P700 Main power board. I also replaced the filter caps. On the filter caps my reference photo didn't show the connection of both red leads so I referred to the schematic. Take a look at my work to look for errors. I did a visual check on the polarity of all the caps I replaced and they look good according to the print on the CB and my reference photo. The polarity on the schematic is wrong for C721 and C722. Before I started the unit powered on and would play with one channel a little lower in output. Now it will turn on and dial lights up but no voltage between J722 (+) and J728 (-) and R781 is getting super hot. The protection relay doesn't activate anymore either.

Original Caps can see 2nd red lead on cap
IMG_0676.jpeg
Installed second red lead per schematic
IMG_0693 (1).jpeg

Here is my cap job
IMG_4069.jpeg
 
Looks like the techs aren’t here or too busy to get involved. Can anyone direct me to a site were I may get help troubleshooting.
Thanks
 
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