AGA black and white TV

[Michael Maurice]

I have been asked to repair this TV which the owner imported from Sweden.

It was dead, having gone bang when the new owner plugged it in.

The fault was the paper wax capacitors across the mains!

Having replaced them I found a Rifa cap in the line 0/P stage that had cracked. When I replaced it I was rewarded with a raster with field problems. (See picture)

The frame stage comprises of a PCF84 and a PCL85.

I have replaced the cathode bias capacitor in the frame O/P stage, but time prevented me from going further.

What might cause this fault?

[Maarten]

It could be a Swedish Philips chassis, I'm not sure which one or whether that's really the case, but you might be able to verify it by looking for labels and numbers on the chassis or the PCB (also in the copper pattern). That way it might be somewhat easier to find a schematic.

[1955APREN]

Faults like this are often due to faulty components in the cathode of the PCL85, you say you have replaced the by pass cap but what about the cathode
resistor has it gone low normally about 270R?

The set does have a Philips look about it. One Philips set had a frame output transformer that had a feed back winding that would go OC causing a fault like yours.

Regards, Derrick.

[Michael Maurice]

I checked the cathode resistor, it's a 390R but it went slightly high.

[its ur aerial]

Looks very much a Philips to me too, cramping at the bottom is normally
always associated with a fault in the Cathode circuit.
what's the voltage on the cathode ?
May be worth investigating Derrick`s suggestion, if the cap and resistor are OK.

Ken, G6HZG.

[Welsh Anorak]

What a strange looking TV! Is it AGA as in the stove manufacturers?

Could you hazard a guess as to the date - perhaps the CRT type will help.
Hopefully the fault shouldn't take too long to track down - the CRT looks good.

[Maarten]

It would have been made around 1960-1965. It's the same AGA as the stove manufacturer. They actually made their electronics themselves and/or bought in from various manufacturers but at some point in time they seem to have switched to Philips made sets. I don't know whether Philips bought the rights to their name or they remained an indepedent trading company.

It would be relatively easy to confirm or reject the Phlips origin of the chassis.

[Richard_FM]

Interesting to see, I wasn't sure if there was a Swedish manufacturer who made their own chassis rather than just make sets around imported major components.

[Maarten]

Luxor certainly made their own chassis.

[German Dalek]

Hi,
I have the same set, and parted 1-2 of them out.
In Sweden these models are called "tombstone" because of their style.
Do you want the schematic?

Regards,
German Dalek

[Michael Maurice]

Originally Posted by German Dalek

Hi,
I have the same set, and parted 1-2 of them out.
In Sweden these models are called "tombstone" because of their style.
Do you want the schematic?

Regards,
German Dalek

I’ve got the set back in the workshop and I’ve got the diagram. I’ll be away for a couple of weeks and will start on it when I get back.

[Michael Maurice]

I've done more work on this set. I've replaced a number of RIFA type capacitors and I found a 1M resistor in the height circuit that had gone high. When I replaced it, I had full scan. Except I have flyback lines at the top of the screen.

i get quite a bright raster with lines, should I not get snow!

The set at first seemed like it was VHF/UHF but there is no UHF tuner fitted.

Did Swedish TV operate on 625 lines at VHF? There is no system switch and it's certainly not 405 line!

As the set has a live chassis, I can't create a video input. What can I use as a converter?

[Lloyd 1985]

Have you got one of those multi standard modulators available? I have one and you can just feed in a signal from a freeview box or DVD player (anything that can output a 625 line signal really!) and then select what channel to output it on, and also set the sound frequency too. Have a look for ‘M69L RF Modulator AV-RF TV Converter UHF VHF Frequency PAL NTSC Standard’ in the usual places. I have successfully used one on an American Motorola 7” TV, in fact that’s what I bought it for, picture and sound were very good, and it didn’t mind having 625 lines fed to it!

Regards
Lloyd

[Michael Maurice]

Hi Lloyd,

Where did you get yours from?

[Lloyd 1985]

Got mine off eBay a couple of years ago, they are available on Amazon and Aliexpress too. There is a version that accepts a hdmi input too!

Regards
Lloyd

[winston_1]

Originally Posted by Michael Maurice

I get quite a bright raster with lines, should I not get snow!

Did Swedish TV operate on 625 lines at VHF?

I would expect snow.

Sweden use 625 lines system B at VHF. Later UHF system G was used as well.

Note also their mains was 220v so you will be overloading it on our 240v.

[Michael Maurice]

There is snow, very faint snow, you can see it by turning the contrast up, the brightness down a bit and changing channels. It does have a 240V setting so I'll make sure its set for that.

[Michael Maurice]

We have a picture and sound! The height doesn't go high enough and there are flyback lines on the top of the picture. I will post diagrams soon.

[roffe]

It's called AGA Mobil 4346.
Lots of AGA TV:s here:
https://www.aga-museum.nl/aga-televisie/

[Michael Maurice]

Here is a scanned circuit of the line and frame timebases