Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise


It is currently Mar Sat 23, 2019 2:34 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 22 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 4:47 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
Interestingly enough, I have a 1950s Royal 500 that works perfectly. But neither of my 1960s Royal 400 and Royal 275 work at all and both radios are in excellent condition. I'm surprised by this because I thought the 400 model was one of their higher end models. I've looked into the back of each radio and each is slightly different. The battery placement differs as well as the component layout. I can make basic repairs to tube radios like replacing bad capacitors but I've never repaired a transistor radio. What do you think is the main thing causing the 400 and 275 to not work and would this be a relatively easy inexpensive fix for me to do? Thanks!


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 5:39 pm 
Member
User avatar

Joined: Jan Thu 14, 2016 9:29 pm
Posts: 42
When you say they don't work at all, do you mean totally silent? Do you hear a click from the speaker when switching on?

If they are both completely dead, start off by checking the basics. Firstly make sure that the battery terminals are clean and free of corrosion, and also confirm that the batteries are inserted with the correct orientation. These radios can be confusing in that respect if you don't have the paper sticker attached to show how they fit.
Another thing to check is the power switch itself. If the radio hasn't been used in a while, the contacts can oxidize. An easy way you can check this is by temporarily jumping the two terminals on the back of the control. I have two Royal 500 and the switches were bad on both of those.


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 6:29 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
Thanks for the tips, videojunkyard. There is no sound at all, no hiss, static, hum or crackling from the volume control. Fortunately, the paper labels are in both the radios and it shows the battery orientation. I tried fresh batteries to no avail. I'll check the power switch as you suggest. One question--do the transistors go bad like tubes can? I thought transistors were virtually foolproof??


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 7:08 pm 
Member
User avatar

Joined: May Wed 01, 2013 10:05 pm
Posts: 1990
Location: Rayleigh, BC, CANADA
Earphone jack!

they are usually the most common failure (no sound), check the wires and the contacts maybe dirty.

_________________
Rocco


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 7:34 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
Rocco, you mean the earphone jack may be causing the sound not to come from the main speaker? I guess I could try inserting an earphone piece in the jack to see if sound comes through it. :shock:


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 7:56 pm 
Member
User avatar

Joined: Jan Thu 14, 2016 9:29 pm
Posts: 42
longhorncutlass wrote:
One question--do the transistors go bad like tubes can? I thought transistors were virtually foolproof??


Yes, transistors can fail, and I've had many older germanium transistors fail, like the ones used in your Zenith. I wouldn't worry too much about that at this stage though. Even with a bad transistor somewhere, you should still get a crackle, pop or some sort of sound from the speaker when you operate the volume/on/off switch. Replacement transistors can still be obtained, or at least an equivalent type to get the set up and running again, should it need any.

There's a wealth of information, and many helpful people on here to guide you through a repair. The main thing is to take your time, take care when working on the printed boards, and be methodical - (you already know this through working on tube sets - the principles are the same).


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 8:41 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
VideoJunkyard, thanks for the kind words. Yes, I may try to tackle repairing one or both of them, but I've only worked on older AA5 and AA6 radios with metal box chassis. I've avoided messing with printed circuit boards. As long as my oldest Zenith 500 works I'm okay.


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Tue 07, 2018 9:05 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 20191
Location: Utica, NY 13502 (USA)
Transistors do fail on occasion but it is far more likely to have one or more electrolytic coupling or by-pass capacitors to go open. Many people routinely replace all electrolytic and paper caps in transistor radios just as they would do in tube sets.

Dave


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 2:13 am 
Member

Joined: Oct Mon 26, 2009 10:02 pm
Posts: 5730
Location: Indianapolis, IN
Both of those radios are well worth the effort to try and repair---and they are not that difficult to work with...

VideoJunkyard is correct---there are several here who will be glad to help you through the process. Here is an old thread of mine: viewtopic.php?f=4&t=310066

You're welcome to the original higher-resolution pics taken during projects if they might help...

Best of luck and keep us posted on progress if you do decide to refurbish them !

John


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 5:58 am 
Member

Joined: Oct Mon 02, 2017 8:53 am
Posts: 91
Location: Panama City, FL 32401
It's also important to check the circuit boards for continuity. As old as the tracks are,they can actually corrode and cause more resistance. I had that happen with a Royal 275 and 500E-1.


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 8:54 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 30494
Location: SoCal, 91387
Transistor circuits are no different than their tube predecessors when it comes to restoration. What's the first thing you do to restore a toob set? Replace the electrolytics, right? Same deal here. AFA an active element going south, yes, it is a possibility, but Transistors are easily as reliable or more so, than tubes.

Rocco's suggestion about the earphone jack is quite valid. Take a look at the "L" shaped outer contact, and determine if the straight inner contact is touching it. Use a screwdriver if necessary to make sure, by pushing on the inner to make it touch the outer.

Most likely however, is that the 60 year old E caps have opened, and simply need replacing.

_________________
\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins//////////////////


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 11:41 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 13609
Probably 75-80% of the small 50s & early '60s electrolytics have now failed. Commonly the ceramic/plastic cases develop a small crack, or epoxy seal fails allowing the electrolyte to dry. Dry cap equals zero capacitance.

The white IEI/Nashville caps are almost always bad.

_________________
Tom


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 4:50 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
To xrhonda91 and all responders, I appreciate all the good information and references to the other thread on these radios. I now have the information I need to at least take a stab at repairing these. Michael


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 5:13 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
xrhonda91, I reviewed your thread and wow, what great detail and pictures. This will surely be a help to me. I like your 400 in that it's white. Mine is a light green, but it did come with the presentation box and the radio and box are in excellent condition. I'll take a pic of it soon and post here. But I like your white one a little better. I wasn't aware the 400 had the large elliptical speaker like the 500H. Would love to own one of those, but they are very pricey.


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Wed 08, 2018 10:01 pm 
Member

Joined: Aug Wed 24, 2011 4:35 am
Posts: 4292
Location: Sunnyvale CA
longhorncutlass wrote:
To xrhonda91 and all responders, I appreciate all the good information and references to the other thread on these radios. I now have the information I need to at least take a stab at repairing these. Michael



You have gotten very good information to date, but just to add the order of likelihood of potential reasons:

1 Bad Electrolytic capacitors
2 Bad Electrolytic capacitors
3 Bad Electrolytic capacitors
4 Bad Electrolytic capacitors
5 Bad Electrolytic capacitors
6 Tin whisker or other wise failed germanium transistor
7 Cracked circuit traces
8 Bad connection or contacts around earphone jack
9 failed volume pot (usually an open carbon track)
10 open speaker voice coil (particularly on direct-coupled radios like the Royal 500 E-1)


Brett


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Thu 09, 2018 5:11 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
**UPDATE** **UPDATE**

For the first time in a few years last evening I tried out the 400 and the 275 and well, the 400 works very well. I guess I wasn't putting in the batteries correctly the last few times I tried it a few years ago even though the instruction diagram is there in the radio. Oh well, it works now. I am in Houston and was able to pull in a San Antonio station at the high end of the dial, and SAT is 200 miles from Houston. One other thing I did to the 400 is that red stud at the top of the chassis. It was loose and I tightened it up. I don't know if that had anything to do with it working or just getting the batts in correctly.

The 275 picked up stations faintly but not nearly as loud as they should be. But at least it works. I don't remember it even doing that.


Attachments:
400 3.docx [211.87 KiB]
Downloaded 48 times
400 2.docx [209.64 KiB]
Downloaded 33 times
400 1.pdf [238.03 KiB]
Downloaded 46 times


Last edited by longhorncutlass on Aug Thu 09, 2018 7:35 pm, edited 6 times in total.
Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Thu 09, 2018 5:55 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 7312
Location: Mountains of Mourne. Ireland.
Posting photos to a forum thread...
The skinny: viewtopic.php?p=2717120#p2717120

Greg.

oh... Looking at the (obsolete) mercury battery diagram inside the rear cover could easily confuse you... :)


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Thu 09, 2018 7:19 pm 
Member

Joined: Feb Fri 24, 2012 3:37 pm
Posts: 27
Greg, many thanks for the instructions on how to add pics. I think I'm making progress, but not fully there yet. I tried your process and it attached a link to my note but not the pic itself. I will continue trying now.


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Thu 09, 2018 8:44 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 30494
Location: SoCal, 91387
I think an easier way to do it is to simply go to paint, perhaps crop as necessary, and then resize down to 800 or less pixels per side. An easy way to determine that is to use a calculator and divide 800 by whatever the size it shows at the bottom of the paint screen for the image. The resulting figure is what you would then enter into the resize box.

_________________
\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins//////////////////


Top
 Profile  
 
 Post subject: Re: Zenith Royal 400 and Royal 275 vs. Royal 500
PostPosted: Aug Fri 10, 2018 12:52 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 6266
Location: Black Hills, SD 57745
I owned a 275, it was a good performer, but it was balky with an intermittent when I got it. Judging by the wear, it had been used awhile though. I traced the intermittent to an unsoldered connection from the factory. The copper landing around a transistor lead had not a drop of solder on it. A little solder and it worked fine after that, still on its original caps. I regret trading it off some years back.

I have a theory about really nice, clean-looking transistor radios that don't work. They were probably a gift that likely failed right at the start or perhaps never worked. One can't just toss a gift from Aunt Tillie or Uncle Hubert. No receipt and the store's in another state anyway. So the radio gets put back in the box, stuffed away in a drawer and forgotten about till decades later.

-Ed

_________________
"Specialization is for insects."
Robert Heinlein


Top
 Profile  
 
Post New Topic Post Reply  [ 22 posts ]  Moderator: Dave Doughty Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: wiscojim and 1 guest



Search for:
Jump to:  


























Privacy Policy :: Powered by phpBB