UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Television Standards Converters, Modulators etc

Notices

Television Standards Converters, Modulators etc Standards converters, modulators anything else for providing signals to vintage televisions.

Closed Thread
 
Thread Tools
Old 15th Aug 2020, 1:12 pm   #1
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Generic Modulator Help

I have a generic rf modulator, that is now stuck in ‘test card’ mode. Ie black screen with two vertical white lines, like you'd find on a VCR.

See pics below, the modulator is capable of PAL/SECAM B/G/H/I/D/K and NTSC M, to select - you press the channel +/- button together on the base and cycle between the sound carriers ie 4.5, 5.5, 6.0 and 6.5. You then switch it on and off to commit the setting. That bit i get..

I have tried every possible key press including powering on with buttons pressed etc but it resolutely refuses to show a picture and remains stuck on the test card.

The polish instructions say the same as the English (according to google translate), neither mention the testcard. Any ideas?

Many thanks



Patrick
Attached Thumbnails
Click image for larger version

Name:	B61A9FFA-8640-4AD1-8A8E-6149A33987B8.jpg
Views:	191
Size:	55.5 KB
ID:	213523   Click image for larger version

Name:	EA71B8AF-CA06-4F5B-AFE8-4580F8043FFE.jpg
Views:	194
Size:	72.2 KB
ID:	213524   Click image for larger version

Name:	28B954E3-4784-4E7A-9C7D-13C74AD4D951.jpg
Views:	190
Size:	85.1 KB
ID:	213525   Click image for larger version

Name:	72D33862-E055-43FC-BAC2-3728EB811118.jpg
Views:	187
Size:	66.0 KB
ID:	213526  
patrickgnl is offline  
Old 16th Aug 2020, 11:25 am   #2
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: Generic Modulator Help

These things are sometimes sold under the brand name "Simply Digital".

Have you tried a different video source? I'm just wondering if it defaults to a "tuning signal" if it doesn't detect a valid input.

Unlikely, but it's the best I can think of.
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 16th Aug 2020, 1:49 pm   #3
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Thanks for the reply Graham, that was an excellent idea, but sadly it didn't work.

I have tried two different freeview boxes, it passes the audio along with a tone and the white striped image. I *have* had it working, but obviously while messing pressed a key sequence in error. duh...

Judging by the number of views and just your (very helpful) comment, it will be destined for The recycling... oh well

Many thanks again.


Patrick
patrickgnl is offline  
Old 16th Aug 2020, 2:44 pm   #4
dragonser
Heptode
 
dragonser's Avatar
 
Join Date: Aug 2009
Location: Carshalton, Surrey, UK.
Posts: 734
Default Re: Generic Modulator Help

Hi,
well it would be a shame to recycle it, as at least it would make a multistandard pattern generator !
I wonder if the similar modulators use the same digital ic's and if there would be a clue in the data sheets ?
I have a dragonsat modulator that can do different standards.. but no instructions with it.. luckily pressing both buttons does the same as on your modulator.
__________________
Regards Peter B
dragonser is offline  
Old 16th Aug 2020, 4:18 pm   #5
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Now theres an idea - although i dont have the knowledge to understand the datasheets.. i am hoping you can help?

Two ICs

1. Elan EM78P153SPJ - 14 pin
2. Atmel 72124C02 - 8 pin

I found the first datasheet, but a bit (read - way) above my skillset. The second seems illusive. Pics of inside attached, it may well be identical to the dragonsat.

Thanks


Patrick
Attached Thumbnails
Click image for larger version

Name:	6FD4095C-328E-4493-82DB-5E3E900E637E.jpeg
Views:	182
Size:	105.7 KB
ID:	213656   Click image for larger version

Name:	CE6A62D0-7CFD-4041-A922-434E7AA8FC8C.jpg
Views:	162
Size:	95.2 KB
ID:	213657  
patrickgnl is offline  
Old 16th Aug 2020, 4:21 pm   #6
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,188
Default Re: Generic Modulator Help

The number to search for on the Atmel part is '24C02'. I am pretty sure it's some kind of E2PROM thing. Is the other IC a microcontroller? THe modulator can itself seems to have an I2C bus going into it (SCL and SDA pins) so presumably that's a bit more complicated than some.
TonyDuell is offline  
Old 16th Aug 2020, 5:08 pm   #7
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Here is the atmel datasheet... I can’t find a way to download the elan chip datasheet... although it does appear viewable online.
Attached Files
File Type: pdf doc0180.pdf (620.8 KB, 100 views)
patrickgnl is offline  
Old 16th Aug 2020, 5:19 pm   #8
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,118
Default Re: Generic Modulator Help

If the problem has occurred as a result of erroneous settings, is there a reset function to return it to "factory settings"? Often these are in the form of a small hole into which a narrow tool (e.g. a cocktail stick) needs to be inserted. I must admit that I don't see a candidate in your images.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is offline  
Old 16th Aug 2020, 6:40 pm   #9
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Quote:
Originally Posted by Dave Moll View Post
If the problem has occurred as a result of erroneous settings, is there a reset function to return it to "factory settings"? Often these are in the form of a small hole into which a narrow tool (e.g. a cocktail stick) needs to be inserted. I must admit that I don't see a candidate in your images.
I had already checked, it was my first thought, i couldnt see one....

Patrick
patrickgnl is offline  
Old 16th Aug 2020, 9:21 pm   #10
dragonser
Heptode
 
dragonser's Avatar
 
Join Date: Aug 2009
Location: Carshalton, Surrey, UK.
Posts: 734
Default Re: Generic Modulator Help

Hi,
the ic I was wondering about was the Ic used to generate the sound and vision rf signals, which would be in the metal case...
if it uses the MC44cc373 ic ( it may not do ) , there is also a Sony ic CXA1929m that might do the similar thing... then the datasheet for the MC44cc373 says there is a test mode.. two white vertical bars and a 1 khz tone...
these ic's are controlled by an i2c bus which would be provided by the ic's you have taken a picture of...
This means that there is no easy way of knowing ( as far as I can tell ) what buttons need to be pressed to switch out of the test pattern mode...
__________________
Regards Peter B
dragonser is offline  
Old 16th Aug 2020, 9:23 pm   #11
Amraduk
Hexode
 
Join Date: Jan 2007
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 453
Default Re: Generic Modulator Help

Hello Patrick,

Try here:

https://www.datasheetq.com/datasheet...AN/EM78P153SPJ

Quote:
Originally Posted by patrickgnl View Post
I can’t find a way to download the elan chip datasheet... although it does appear viewable online.
Regards,

Dave.
Amraduk is offline  
Old 16th Aug 2020, 9:34 pm   #12
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Thanks for your replies and help folks....
patrickgnl is offline  
Old 17th Aug 2020, 1:50 pm   #13
Andy Doz
Hexode
 
Andy Doz's Avatar
 
Join Date: Feb 2011
Location: Gloucestershire, UK.
Posts: 376
Default Re: Generic Modulator Help

Looks very similar to the CCT811... make sure you fit a fuse somewhere...

I wrote about it here ..

https://andydoz.blogspot.com/2016/02...epair-and.html

and

https://andydoz.blogspot.com/2016/07...e-failure.html
__________________
andydoz.blogspot.com
Andy Doz is offline  
Old 17th Aug 2020, 7:48 pm   #14
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Thanks for the links, youre right its exactly the same. It is fused at plug, i am always dubious of cheap chinese stuff and tend to unplug it when i am not using it anyway.

So i now not only have a device stuck in test screen mode, but an electrically unsafe one at that. Recycling here it goes...

I wonder how many folk die of electrocution/electrical fires in china? So much of their generic unbranded stuff is so dodgy, it does make you wonder..

Thanks again.


Patrick
patrickgnl is offline  
Old 24th Aug 2020, 8:07 am   #15
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Generic Modulator Help

It's only a small item to store. As soon as you dump it you will discover a cure! John.
Heatercathodeshort is offline  
Old 24th Aug 2020, 12:25 pm   #16
patrickgnl
Pentode
 
Join Date: Jun 2016
Location: Stourbridge, West Midlands, UK.
Posts: 115
Default Re: Generic Modulator Help

Actually that is what i have done, ive put it back in its packaging and written on it the issues, then put it with all of my other shizzle...��
patrickgnl is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:20 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.