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  #1  
Old 10-05-2015, 11:38 PM
goat1981 goat1981 is offline
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Philco Safari Problem - raster and weak sound, but no picture - please help!

Hello, everyone,

Thank you in advance for your help. I am new to this forum, but have found a lot of great info on here.

I recently acquired a Philco Safari for 30 bucks at a flea market. I have never seen anything like it before and had to buy it (and one of the reasons I found this great forum!).

I was disappointed to find that it doesn't work properly. It produces what seems to be a full raster, but has absolutely no image (just a grey rectangle - see attached picture). There is also weak/scratchy sound that comes through when I inject a signal from my DVD/modulator combo, but no picture.

I replaced the electrolytic, bipolar, and paper capacitors, but no significant improvement.

I took some voltage readings, and it seems some things are off.

According to the service manual I found, there should be a -6.5v, -5v, -11v, and +11v source (all VDC) for the boards.

I measured the -6.5v source at the filter cap and got a reading of -5.6v
I measured the -5v source and got a reading of -4.5v

These seem a bit low...but not as bad as the +/- 11v sources, which measured 8.35 and -8.85v respectively.

I have attached the portion of the schematic that shows the +/- 11v sources. It seems this voltage is derived from the flyback transformer.

I also checked the voltages at test points 1 - 5 on the boards. I have attached clips of the service manual that describe what the test points are and what voltages should be.

Test points 1 and 2 were spot on. These are on the sweep board. Both measured around -.35vdc, which is exactly right according to the service manual.

However, test points 3 - 5, which are on the video/sound board, are all way off:

Point 3 should be +1.5v; it read -.18v
Point 4 should be +10v; it read 7.44v
Point 5 should be +.05v; it read -.05v

It just seems like the video/sound board isn't getting enough power, but I don't know why the +/-11v supply is so low.

Any help would be very appreciated. I would like to get this set to work. :-)

Thanks!
Attached Images
File Type: jpg IMG_1248.jpg (47.1 KB, 45 views)
File Type: jpg Screen Shot 2015-10-05 at 11.08.37 PM.jpg (80.7 KB, 32 views)
File Type: jpg Screen Shot 2015-10-05 at 11.09.34 PM.jpg (115.0 KB, 17 views)
File Type: jpg Screen Shot 2015-10-05 at 11.09.49 PM.jpg (127.3 KB, 17 views)
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  #2  
Old 10-06-2015, 01:14 PM
zeno zeno is offline
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First thing if you havnt check C20 & C22.
After that find what they run in the set.
Guess is the vert or audio out. Cant tell without the
schematic. Also cant tell what the TP's are for.
Keep in mind voltages are usually not spot on. Many
depend on signal & control settings. Sams tells u the
conditions.
One test you can do is change channels & see if
the screen shows the contacts making & breaking.
Streaks should go through the pix.
If it does its tuner related if not its IF related.
Put up the schematic & a bunch of us will work on it
with you.

BTW you stole the set. Its the first solid state set ( except HV tubes)
sold. VERY collectable so treat her nice.

73 Zeno
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  #3  
Old 10-06-2015, 02:35 PM
Electronic M's Avatar
Electronic M Electronic M is offline
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I have a parts chassis (no cabinet trim no CRT) if you need anything.
__________________
Tom C.

What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4

Reading between the scan lines since the mid 2000's.
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  #4  
Old 10-06-2015, 04:23 PM
Olorin67 Olorin67 is offline
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Welcome to the forum. I'm sure some of the guys here have worked on those and can give you Ideas. With anything of that vintage, electrolyic capacitors are very suspect and should be changed. As well as any paper caps. If any transitors are bad that coud be a challenge to find equivalents that will work. They are probably Germanium, I don't think you can subsitute modern silicon ones in most circuits. definitely a collectable set. I passed up a couple opprotunities to pick one up cheap in the past, wish I had bought them.
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  #5  
Old 10-06-2015, 07:27 PM
goat1981 goat1981 is offline
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Thanks for the replies, guys!

Quote:
Originally Posted by Electronic M View Post
I have a parts chassis (no cabinet trim no CRT) if you need anything.
Thanks for this as well! I may contact you if I need to purchase a part based on what everyone says.

Here is a link to the schematic (JPEG image on my box account)

https://app.box.com/s/8p6u58ccdusfxwhzi36npmc4t34aawyx

I have already replaced all the electrolytic (polar and non polar) and paper caps, but have left the ceramic caps alone. Still have only raster, scratchy sound and no pic. Changing the channels does nothing to what I see on the screen.

The test points are described in the service manual as follows:

TP1 should be -.35V and is the Horizontal Oscillator Base (reads on spec)
TP2 should be -.35V and is the Horizontal Stability Coil (reads on spec)

Test Points 3 - 5 on the Video/Audio/Sync board are quite off.

TP 3 should be 1.5V and is the Video IF Bias (reads -.2V)
TP 4 should be 10V and is the 1st Video Base (reads 7.4V)
TP 5 should be .05V and is the Sync Sep Base (reads -.05V)

Again, the +/- 11 volt supply reads quite low at around +/- 8.5v.

Thanks again for all your help.

Last edited by goat1981; 10-06-2015 at 07:31 PM.
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  #6  
Old 10-07-2015, 11:29 AM
zeno zeno is offline
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For now measure voltages on all 4 IF & the video out transistors.
Look for something way off. The +11 runs most of the low level stuff
& may be getting loaded down.

73 Zeno
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  #7  
Old 10-07-2015, 12:42 PM
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Zenith26kc20 Zenith26kc20 is offline
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Be careful, the transistors ARE germanium. If I remember correctly, Philco developed the surface barrier transistor that made this set possible. These sets usually have dried out electrolytics causing all kinds of symptoms.
I would get a cheap ESR meter to check the electrolytics. Since they are mostly low voltage, the ESR meter can find them easier than the high voltage ones.
Once working these sets are great!
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  #8  
Old 10-07-2015, 01:04 PM
goat1981 goat1981 is offline
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Quote:
Originally Posted by Zenith26kc20 View Post
Be careful, the transistors ARE germanium. If I remember correctly, Philco developed the surface barrier transistor that made this set possible. These sets usually have dried out electrolytics causing all kinds of symptoms.
I would get a cheap ESR meter to check the electrolytics. Since they are mostly low voltage, the ESR meter can find them easier than the high voltage ones.
Once working these sets are great!
I have already replaced all the paper/electrolytic capacitors, so those shouldn't be an issue.

I'll start checking voltages in the IF stages when I have some time. Any other opinions/suggestions are welcome in the meantime.

Thanks for your help, everyone.
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  #9  
Old 10-07-2015, 01:38 PM
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rca2000 rca2000 is offline
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WELL...a question I asked some months ago...has been ASNWERED !!

The safari DOES use the flyback...for some Low B voltage sources !! NEVER knew this...

SO...I would have to wonder:: Is the voltage TO the flyback--looks like a 5 volt supply--OK? If NOT...ALL outputs will be LOW..

And like others have said...it is possible--you have a heavy load on the 11 volt source...

I ASSUME...the diodes in this set are silicon. If NOT...if they are SELENIUM...CHANGE them--they DO get WEAK--OFTEN.
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  #10  
Old 10-07-2015, 10:15 PM
goat1981 goat1981 is offline
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Hey guys,

I just got done taking voltage readings of all the IF stage transistors, the Video Amp transistor, and the Video Output transistor and found some interesting results (especially the video out transistor...)

Here are the readings in order of what's specified on SAMS and what I read with my multimeter.

Supply Voltages:
-5v -- reads -4.4v
+11v -- reads +8.2v
-11v -- reads -8.8v

First IF Transistor (X1)
Base -- 1.5v -- reads 0.85v
Collector -- 0v -- reads 0v
Emitter -- 2v -- reads 1.22v

Second IF Transistor (X2)
Base -- 2.0v -- reads 1.27v
Collector -- 0v -- reads 0v
Emitter -- 2.2v -- reads 1.57v

Third IF Transistor (X3)
Base -- 8.5v -- reads 6.62v
Collector -- 0v -- reads 0v
Emitter -- 8.6v -- reads 6.77v

Fourth IF Transistor (X4)
Base -- 8.5v -- reads 6.37v
Collector -- 0v -- reads 0v
Emitter -- 8.6v -- reads 6.58v

Video Amp Transistor (X5)
Base -- 10v -- reads 7.28v
Collector -- 4v -- reads 2.84v
Emitter -- 9v -- reads 7.5v

Video Output Transistor (X6) -- here is where the problem is...
Base -- 9v -- reads 6.65v
Collector -- 9.5v -- reads -8.66v (!)
Emitter -- 0.5v -- reads 8.11v (!)

Could it be a bad Video Output transistor? I haven't replaced any of the diodes, which are the original 1N60A germanium diodes -- these seem pretty common and I can replace them if you think it'll help.

What do you guys think about these readings? If you missed the schematic, I included it in a previous post.

Thanks again for your help!

Last edited by goat1981; 10-07-2015 at 10:20 PM.
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  #11  
Old 10-08-2015, 01:15 AM
goat1981 goat1981 is offline
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An update!

I found broken circuit traces on the Video/Audio/Sync board! This TV must've undergone some kind of trauma in the past. Maybe it was left in the heat or dropped?

I found four traces that lacked continuity. I found this when I was checking voltages and two points on the same trace had different voltages...

https://app.box.com/s/s3yxjeabwn8b6k27act3jygq3k2ou2uv

I soldered in some jumper wires and got a picture and sound!

https://app.box.com/s/pjip2xjvoovx1dz86p9l2ztkmjgziflw

There are still some issues, but this is progress. The focus and linearity aren't that great. Also, I am having trouble getting clear sound. There is a buzz that slowly goes in and out in the sound. I uploaded a video of this behavior on my box account. Link:

https://app.box.com/s/txgqhar3szysgyitb9jta9evc6f6fvua

I am wondering if it's the type of modulator (a cheap one I bought at Walmart) that I'm using, because the same thing happens on a Sony 5-303W that I have. Either that, or both TVs have the same problem (I haven't really worked too much on the Sony yet).

Thoughts? Could it be bad diodes? Again, thanks for all of your help!

P.S. Sorry for the huge pictures. Any way to control that?

Last edited by goat1981; 10-08-2015 at 10:39 AM.
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  #12  
Old 10-08-2015, 08:13 AM
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Zenith26kc20 Zenith26kc20 is offline
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The modulators can produce the hum, especially when graphics are present. A lot of us use agile modulators to prevent that. I use a Blonder Tongue AM-60-550A. You can get one at a reasonable price on our favorite auction site.
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  #13  
Old 10-08-2015, 11:52 AM
goat1981 goat1981 is offline
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Quote:
Originally Posted by Zenith26kc20 View Post
The modulators can produce the hum, especially when graphics are present. A lot of us use agile modulators to prevent that. I use a Blonder Tongue AM-60-550A. You can get one at a reasonable price on our favorite auction site.
Thank you for your suggestion - I will look one up.

Any suggestions for improving the picture quality (especially brightness/contrast and focus)? I haven't replaced any resistors; and many of them may be out of spec. I'm sure it needs to be aligned as well. I'd like to learn to do this, but know that it requires a lot of equipment that I don't yet own.
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