View Full Version : Admiral 16" Hybrid Color - No HV


maxm
10-30-2015, 10:50 PM
I got this set at an estate sale in 2013 and finally took a look at it.
T7K101C chassis, in Sams 1182.

It has had some repairs done in the past, tubes replaced, one of the filter cans replaced and some soldering on the boards. Who ever did the work was kind of sloppy, it looks like they lost all the screws that secured the chassis and back cover and managed to find assorted replacements for half of them.

It currently powers on with sound, but there is no high voltage. I don't hear any noise from the flyback.

Unfortunately I don't have a lot of experience troubleshooting this stuff. I don't have the Sams, but can check at my library.

I would appreciate any advice.

Thanks,
Max

Captainclock
10-30-2015, 10:57 PM
I got this set at an estate sale in 2013 and finally took a look at it.
T7K101C chassis, in Sams 1182.

It has had some repairs done in the past, tubes replaced, one of the filter cans replaced and some soldering on the boards. Who ever did the work was kind of sloppy, it looks like they lost all the screws that secured the chassis and back cover and managed to find assorted replacements for half of them.

It currently powers on with sound, but there is no high voltage. I don't hear any noise from the flyback.

Unfortunately I don't have a lot of experience troubleshooting this stuff. I don't have the Sams, but can check at my library.

I would appreciate any advice.

Thanks,
Max

Did you check the HV tube? It looks like you might have a tube powering the HV and if that tube is weak or bad then you won't have HV.

zeno
10-31-2015, 09:32 AM
Check the green bel-fuse first. Its the little square thing
by the damper tube. Also the flyback looks questionable
but had to tell in a pix. Looks like it got real hot. See if
it has a burned tar smell.

73 Zeno:smoke:

Findm-Keepm
10-31-2015, 09:59 AM
...and if you need a green Belfuse, lemme know. I've got at least one or two...

Username1
10-31-2015, 10:58 AM
Looks Sanyo-ish ~ Who really made it ?

.

dieseljeep
10-31-2015, 11:10 AM
Looks Sanyo-ish ~ Who really made it ?

.

I have one of those! Made in Taiwan by Admiral Overseas Corp.
Most of the tubes are cheap, at the Florida tube place. AFAIK, those Admirals were the only one that used those odd-balls.

drh4683
10-31-2015, 11:22 AM
Wow, that's a set you don't see! Glad you saved that one!

And i agree, certainly check the green belfuse. If it's good, I'd check to make sure you have proper negative bias on the HOT which would tell if the horizontal oscillator is running. I might have a tekfax for that chassis and will check later today.

As for who made it, Admiral always made and designed their own sets. In 1967, Admiral was one of the first manufacturers to open a plant in Taiwan, known as "Admiral Overseas Corporation" or "AOC" as it was officially called until Rockwell (who acquired Admiral in 1974) sold Admiral and the AOC arm in 1978. An eastern business group who purchased AOC changed the name to "AOC international" which still exists today.

This set looks like it has a lot of domestic parts in it even though it does indeed have a somewhat "Japanese look" to it. I've got a 13" version of this set from 1974 which was made in Taiwan and has a similar look with some domestic parts. This one could be a real deal Harvard, IL built set. I think Taiwan focused primarily on portable sets and radios while most of the big consoles were still built in Harvard.

Max, does the back cover have "Taiwan" molded on it?

drh4683
10-31-2015, 11:24 AM
Ah ha! Dieseljeep replied as I was writing my first post. So this one is indeed an AOC made set, which is still a real deal Admiral designed and built set, just made in Taiwan.

zeno
10-31-2015, 01:37 PM
IMHO this is a real US built Admiral. It screams Admiral.
The only AOC tube sets I remember were a 12" & 16".
They were very distinctive inside & out. You would never
guess Admiral with the back off. Of course they may have
set kits over at first like Zenith sent to some countries.
The layout of the set is the same. Funny thing is when
Admiral went away AOC sets looked like US built Admirals for
years & kept the same part ## scheme. The first few yrs
they were quite good. Then they used what we called Goodyear
FBT's. They were good for a year then went up in smoke.......

One other very common thing on both B&W and colors
was the hoz hold coil would get smashed in. We ordered
them & the shafts by the dozen. That will kill your HV
& maybe the h output tube.

73 Zeno:smoke:

drh4683
10-31-2015, 01:58 PM
Schematic photos attached.

https://farm1.staticflickr.com/568/22655608461_231a64ad49_k.jpg (https://flic.kr/p/AvZV5Z)IMG_20151031_125116070 (https://flic.kr/p/AvZV5Z) by drh4683 (https://www.flickr.com/photos/135332734@N02/), on Flickr

https://farm1.staticflickr.com/741/22618360076_72c40f0258_k.jpg (https://flic.kr/p/AsH1rs)IMG_20151031_125123334 (https://flic.kr/p/AsH1rs) by drh4683 (https://www.flickr.com/photos/135332734@N02/), on Flickr

maxm
10-31-2015, 05:21 PM
Thank you for the responses and to Doug for posting the schematic photos.

It looks like there may be a power supply problem. I get very low voltages on all the tubes. It looks like there were some repairs to the power supply previously. CH8 and RE71 were replaced. The 3 diodes, RE70, RE71, and the green and black fuses tested OK. I seem to loose voltage around CRE3 and CRE4, but may not be measuring correctly, or misreading the schematic.

This set appears to have been assembled in the US, there are a few marked US components, including the white ceramic capacitors and the HV rectifier tube. There are a lot of foreign components, the flyback is from Taiwan, the power resistors are Matsushita. Back is not marked Taiwan, but nothing definitively identifies where it was assembled, though the model label lists Chicago.

The tubes are odd, it seems like they came out with a lot of new tube types for very specific applications right when things where changing to solid state. I had to find an updated test settings book for my tester to check them.

zeno
11-01-2015, 10:05 AM
CH8 is high failure on any set that uses it. Its a voltage
doubler supply. I think I see it wrapped in tape.
If it were the right part it would be wrapped in cardboard
or sometimes plastic. The wrong cap will have a short life,
heat will kill it fast. For now you can hang a close value
cap across it & see if it comes up. If thats it our cap
expert can select the right replacement for you.

73 Zeno:smoke:

old_coot88
11-01-2015, 02:26 PM
Sure hoping the flyback is still good. Admirals using feedback-type HV regulation (which this one uses) were notorious flyback-eaters.

maxm
11-01-2015, 05:16 PM
I'll unwrap the tape from CH8 and see what was used, whoever replaced it did a sloppy job and who knows if it was the right part.

The flyback does look like it got hot, but doesn't smell burnt or have obvious damage.

maxm
11-01-2015, 06:43 PM
I took at CH8, it calls for a 350uf @ 200V. The replacement cap previously installed was 300uf. I took it out and it measured around 130uf. All the extra caps I have to substitute are lower values except for a 500uf. Could I use the 500 to test briefly?

rca2000
11-01-2015, 08:27 PM
Yes--you can use that 500UF, since I do not see another cap on the doubler ckt. Though it looks like some of the schematic is MISSING. There SHOULD be another cap in the ckt.

BUT....you REALLY need to make sure that resistor and the thermistor in line with that cap are not open. RE71 and RW71.

zeno
11-01-2015, 09:09 PM
Fine for quick test, be sure its a 200V +
The temp rating is important on these, dont remember but
I think they were 85 deg C.
Our cap expert is probably reading the mail but hasnt piped in yet.

Was too common for a lazy tech to use the wrong thing just to
get it out & save buying a part. Could tell lots of stories about
the butchers in the biz that made us look bad......

73 Zeno:smoke:

I took at CH8, it calls for a 350uf @ 200V. The replacement cap previously installed was 300uf. I took it out and it measured around 130uf. All the extra caps I have to substitute are lower values except for a 500uf. Could I use the 500 to test briefly?

Jon A.
11-01-2015, 09:38 PM
I have one of those! Made in Taiwan by Admiral Overseas Corp.

This set looks like it has a lot of domestic parts in it even though it does indeed have a somewhat "Japanese look" to it. I've got a 13" version of this set from 1974 which was made in Taiwan and has a similar look with some domestic parts. This one could be a real deal Harvard, IL built set. I think Taiwan focused primarily on portable sets and radios while most of the big consoles were still built in Harvard.
I always thought it strange that my Admiral console's K20 chassis has "Made in Taiwan" on the delay line. I don't see an indication of origin on any other part.

maxm
11-01-2015, 10:37 PM
Success - I clipped in the 500uf cap and got a raster with a color picture. Picture isn't great, I'll likely ask for more help once I get the correct cap installed.

Would it be a good idea to replace the few white ceramic tubular caps? I've replaced them on Portacolors because I've heard they can go off with a bang.

This delay line in this set is also marked Made in Taiwan.

Electronic M
11-01-2015, 10:54 PM
Success - I clipped in the 500uf cap and got a raster with a color picture. Picture isn't great, I'll likely ask for more help once I get the correct cap installed.

Would it be a good idea to replace the few white ceramic tubular caps? I've replaced them on Portacolors because I've heard they can go off with a bang.

This delay line in this set is also marked Made in Taiwan.

As a general rule I replace those white Ceramic tubular caps (usually Elmenco brand) when I find them regardless of the application....I've seen enough bad ones not to trust them.

rca2000
11-01-2015, 10:54 PM
Put in a 330 uf at 250 or 200 volts...and you will be fine. it should mount under the chassis.

rca2000
11-01-2015, 11:37 PM
BTW...I am GLAD you are 'rounding third" on this set. i was hoping it was a ps problem....and NOT a bad fly or such. Now--it looks like the fly has potential after all.

I HAD One of the 13 inch sets like this...about 1981 or so....but was too YOUNG at the time...and with NO schematic or ANYONE to help me....I was not able to figure out MY dead set wiht tubes lit problem....and was MADE to dump the set in spring of that year" for my safety"... likely had a bad doubler cap or open thermistor or such...but I will never know...


It would be NO problem today....and NO ONE is going to make me dump ANYTHING anymore...

dieseljeep
11-02-2015, 10:06 AM
Fine for quick test, be sure its a 200V +
The temp rating is important on these, dont remember but
I think they were 85 deg C.
Our cap expert is probably reading the mail but hasnt piped in yet.

Was too common for a lazy tech to use the wrong thing just to
get it out & save buying a part. Could tell lots of stories about
the butchers in the biz that made us look bad......

73 Zeno:smoke:

It could've been bought at a second-hand TV store.
They just bubble-gumed the repairs, to sell them. It's old enough to have some kind of history behind it.

dieseljeep
11-02-2015, 10:30 AM
Ah ha! Dieseljeep replied as I was writing my first post. So this one is indeed an AOC made set, which is still a real deal Admiral designed and built set, just made in Taiwan.

Looking at some of the components, it probably is one of the last US assembled chassis.
I had a strange problem with one of the first Taiwan built 19" Admiral chassis. It had a bad hum bar running through the picture.
Naturally, I bridged the PS 'lytics, no improvement! Finally, took the scope to it. Same wave-form on both sides of the choke. I subbed it with one from a scrap RCA chassis. The Taiwan made choke had shorted turns. Left the RCA one in there, as it worked fine.
I see the set in the picture, has the low voltage focus CRT, blue gun on the bottom.

Electronic M
11-02-2015, 02:28 PM
I see the set in the picture, has the low voltage focus CRT, blue gun on the bottom.

So as a general rule did all LV focus tubes have the blue gun at bottom? On those tubes did they have the HV connector at top and the blue gun at bottom, or did they put the HV connector and blue gun on the same side and only upside mount the CRT upside down?

Bill R
11-02-2015, 06:23 PM
The CRT in my RCA CTC22B had the blue gun on the bottom and the HV connector on top or right side, I don't remember. It was not installed upside down.

Username1
11-02-2015, 06:30 PM
I had a Toshiba low voltage focus, Blue on top, and HV lead on top also.

12 or 13" set... only a few transistors in it, mostly signal & color, rest tubes...

.

maxm
11-14-2015, 09:36 PM
I replaced the bad electrolytic as well as the ceramic tubular caps. I now get a color picture with very poor contrast and diagonal horizontal lines. Two of the attachments show the picture with a signal, one should be snow. The brightness and contrast controls have no effect on the picture. Color and tint do. The vertical is also very unstable. I got a copy of the Sams schematic I can reference.

rca2000
11-14-2015, 10:11 PM
Looks like a loss of the VIDEO signal. You have COLOR....but NO video 'behind it" to "control it". Looks a LOT...like an open delay line.

old_coot88
11-14-2015, 10:33 PM
Classic case of loss of the luma signal with color information intact. Most frequently caused by
1. Dirty service switch (if set has one).
2. Heater-cathode short in the CRT. It will usually show up by tapping on the CRT neck.

(The video/luma signal does not "control" the color signal. They are two separate signal chains.)

rca2000
11-14-2015, 10:57 PM
By"control" I mean it gives the chroma it's LIGHT and DARK information, allowing it to accurately produce the correct shades of color. Without the luma...you get ONLY blotches of color info, that does NOT look anywhere useable...

And YES...make sure the service switch, if any, is not dirty, or has NOT been accidently placed "midway", or broken off.

Electronic M
11-14-2015, 11:32 PM
Also look for bad video amp tubes in the luma chain, and if you have a scope check the waveforms/amplitudes in that chain.

maxm
11-16-2015, 09:35 PM
I cleaned the service switch, that seems to have corrected the color issue, glad it was something simple, I should have done that at the beginning. I replaced two electrolytics in the vertical that stabilized the vertical and let me fill the screen. I now have a pretty good color picture (photo did not come out well).

zeno
11-17-2015, 09:43 AM
That actually looks pretty darn good & close to how
they looked in the olden days. Well done:banana:

73 Zeno:smoke:

Findm-Keepm
11-17-2015, 09:58 AM
Hotlips looks good! Great job!

DavGoodlin
11-17-2015, 03:52 PM
:sigh:These sets were not rare at one time. I recall working on a few at the Admiral-Zenith store where I bench'ed during tech-school in 82-83. But I had seen some K10's for the first time in 1979 and it was quite an introduction :)

This little Admiral set was used in a troubleshooting contest I entered in 10th grade Vo-tech.
I won the VICA (vocational-industrial club of America) regionals in suburban Philadelphia (thanks to a 1966 Philco color - just like one I had at home :D, which had an open color bandpass transformer), and the state competitions were held at a "convention/resort" venue just 2 miles from where I now live. I still relive that day when I drive by. I placed 3rd among 8 - BTW.

There were about 8 stations set up with "troubles" introduced into each Admiral. Each chassis was pulled out, cabling extended and mounted on a piece of particle board fastened to the cabinet bottom, hinged so it could be tilted up for voltage checks, etc. Due to my relative unfamiliarity I choked on about half without noting the bad component. It was really simple since tubes were all assumed good and it was impossible to "spot" a fresh solder joint, etc.

Boobtubeman
11-17-2015, 05:10 PM
I recall that scene... he just got done giving her a shot and admiring her butt :D

SR