Marantz 2275 no sound

[sweetspott]

Hello all! I'm a newbie here and novice to vintage HI-FI gear! I would like to get some input on an issue I'm having with my Marantz 2275.It's was purchased new by my dad back in the day.

Unit worked fine till last week! It powers on now and lites up,but no sound! I have taken the cover off and noticed 2 fried/melted diodes on the power supply board(p800 board according to the service manual) The location of the 2 diodes on the board are h808 & h811. Is this the cause of some other issue in the receiver or do I look to find & replace just these 2 diodes? Or do I just look for a complete board to swap out...can this board be overhauled? Any help would be appreciated

 

[archie2]

All of a sudden no sound or prior problems like scratchy volume control, noise or static? You can replace the diodes or the whole board if that's all that was damaged. I'd trace the reason why the diodes cooked first.
Welcome to AK

 

[sweetspott]

Thanks for your reply and welcome to AK!

Yeah..it was working fine prior to this issue! The last time I turn it on there was hum with the volume off for about 30secs,there was no sound at this point! The hum stopped and I got a wiff of the diode melting! It now lights up,but thats it!

I assumed the diodes cooked as a result of primary issue! I have no knowledge of how to trace this problem. If it was a board to replace maybe I'd try that myself,but I doubt I can find a board. Maybe I can send this board out for an overhaul?? Is there any chance the diodes cooked as a result of another bad part on the same pc800 board? I was looking for a similar issue in other posts,and someone mentioned a hum with the volume off as a result of the 2 big filter caps near the power supply. That unit was stated to still have sound though!

 

[archie2]

You turned it on, got a hum then turned it off and the hum continued for 30 secs accompanied by burning smells? Overhauling the board and re-installing may just result in more blown diodes. It may be a bad power cap but there's no way of telling sight unseen. If you have limited knowledge I'd take the whole 2275 to a competent tech to trace the primary problem.

 

[sweetspott]

Sounds logical! I would prefer to bring it to someone who knows what their doing. Where could I bring this for service? I live in Rhode Island.

I left it powered on till the hum stopped & then I smelled the diode about 30secs all together..then shut it down. If I turn it on now theres no hum just the lights & no sound.

 

[archie2]

It depends on whether you want the work done locally or are willing to ship it out. You could call Public Sound in Providence or as there are many competent techs in AK one of them might be able to help you out. I'd seek out someone with expertise and a good reputation in repairing Marantz for the 2275. It's going to cost however.$$$$, just be aware.

Edit: Do a search on AK to find out the better Marantz techs as recommended by AK members.

 

[sweetspott]

Thanks again. I'll do a search for a tech.I'm going to have it checked out. I'll let you know how I do in time
Public Sound's Phone# is disconnected...

 

[Oerets]

Sweetspott,
I'd be looking on the power supply board for a short . Maybe if you update your profile with a location someone close to you might have a tech close .

Until then leave it unplugged , you do not want to mess anything else up . Like the transformer ......




Barney

 

[sweetspott]

Thanks for your reply Oerets! I don't have the know how to search for shorts.If the primary issue stems from this p800/power supply board, swap it out with another? Is it a big costly gamble to just change the power supply board/p800 all together? Is this board in other model Marantz

 

[Oerets]

The P-800 board on the 2275 was used on other units , but unsure if values of some of the component parts are different .

I believe there to be a SM in the data base for the 2275 .

The unit you have is a very nice model and well worth fixing up . The board you have can be fixed .

Have you checked to see if the fuse in the holder on back cover is the right size , not replaced with a higher value .

If you are planning to repair this yourself consider building a dim-bulb tester .
http://antiqueradio.org/dimbulb.htm


Barney

 

[archie2]

There are 3 diodes on the P800 board, H808, H809 and H810. Are all of them fried?

 

[sweetspott]

Thanks...It sounded great for years! I'd like to have it work again!

The fuse is right!
250v 5amp

The diodes that are cooked on the p800 board are at h808 & h811. It looks to me as if h808 heat damaged h811. I dont think the h811 is the problem. the h808 is melted..you can see it in the pic. These are located almost in the center of the board next to the big caps

 

[catrafter]

Lots of good info from Aokman and a cap list from Pacific Stereo in this thread.
H808 and H811 are dual common cathode rectifiers and each can be replaced by 2 1N4007 rectifiers.
If H808 cooked, C801 is probably shorted. I'd replace all the electrolytics and the relay and be done with it. Cheap insurance.

Tom

 

[sweetspott]

Thanks for your input catrafter!

I saw the thread you included..good pics! the p800 was stripped down and re-done! H808 & H11 were not replaced in that thread..right? So when changing the electrolytics/caps it's not common practice to change H808 or H811 unless you cook them? I suppose thats why you change the caps to begin with..to avoid the issue I have. I would like to have my p800 board redone and go from there. I'm going to find a tech that can help I cant do this work myself! I'd maybe try to remove the board thats about it.Then send it out!

 

[archie2]

Do you have the service manual for the 2275?

 

[sweetspott]

yes...pdf download of the 2275 service manual

 

[tarior]

I'd maybe try to remove the board thats about it.Then send it out!

Whatever you do, don't take that board out. The whole unit needs to go to a tech and be repaired properly. Hopefully, there is someone good fairly close to you.

 

[catrafter]

Whatever you do, don't take that board out. The whole unit needs to go to a tech and be repaired properly. Hopefully, there is someone good fairly close to you.

:yes:

Tom

 

[archie2]

Whatever you do, don't take that board out. The whole unit needs to go to a tech and be repaired properly. Hopefully, there is someone good fairly close to you.

+2. What he said and I said in a previous post. Do not switch out the board by yourself as I think you were thinking about if I read some of your posts correctly.

 

[sweetspott]

Yes, I was thinking about taking out the board myself. BAD IDEA I take it...lol. I gather the whole unit would be need by the tech to diagnose correctly!

I'm looking into local techs right now to avoid all the shipping hassles & cost. Nobody near by is listed as a Marantz speacilist though. Like the techs you find here on this website

Their are some local techs that state they do it all TV,APPLIANCES,RADIO,& 25+ years in the business.

I'm getting techs who state they will look at the 2275 for about $30 to diagnose the issue.
What are your guys opinions about a general tech/tv repair man taking a shot at working on a Marantz like my 2275. Or Is it best to get a Ferrari tech to fix a Ferrari!