Future Repair Project - Vintage Philips Leonardo Luxus Tube/Valve Television

[Ysjoelfir]

Hi!
A few weeks ago I got a Philips 21 TD 293 A 00a "Leonardo Luxus" monochrome tube/valve television. Even though I don't watch TV (for over 10 years now) and my lovely girlfriend already tried to convince me that I should convert the TV into an aquarium, I couldn't let go of that beauty as it is in realy good shape and worked a few minutes when my uncle picked it up for me - I know that you should never start any that old without taking precautions and wind it up slowly using an variac, but neither did my uncle nor the seller... so it went like "yay, I work! For the first time in 30 years I can show my ..*BOOOOOM*". I have no Idea so far what blew up, but I am passionate to find that out.
As this is a side project I am not realy in any kind of hurry, but for a few days now I am looking for a service manual for that puppy. Maybe someone has any information about that? I found an auction on ebay but I am sure that there must be a way to get that for free.
I will post pictures soon, if someone is interested?

[Balaur]

Radio Museum seems to have the schematic at least, but there are membership fees.

http://www.radiomuseum.org/r/philips_leonardo_luxus_23td405a23.html

[OldSchoolTechCorner]

For tube TV's and radio's as also do restore them. You can find a manual here.  More likely you could have blew a capacitor. Some of these older set's use bumble bee capacitors that look like over size resistors and those usually go leaky, or short. Don't know if this set use them. But something to watch out. You need to look at the Chassis # to find manual.

https://www.samswebsite.com/

[Ysjoelfir]

Hi!
Yes, the radiomuseum has the schematics, but as you said, they want a ridiculous high members fee. And after you payd that, you even don't have any warranty that you have complete access to everything. I know someone who paid the fee, downloaded the schematics that he needed, and that was it. A week later he wanted to download another schematic and found out he got kicked because of not posting anything at the forums over there.  He never got any refund. So.. Radiomuseum is one of the last websites I would pay anything for. Sorry. Just my personal oppinion.



Oldschooltechcorner, thanks for the link to samswebsite, but sadly they got nothing for the 21td293. I will surely look out for bad caps, as I have some (even though not that much) experience regarding tube powered electronics. I already found a leaky cap that was sealed by wax inside the high voltage cage by my first visual inspection. Because my air compressor isn't working at the moment I can't blow the huge amounts of dust away to find more. But as I said, this is a side project, so I don't have any hurry

[T3sl4co1l]

Yeeeah... never turn on old equipment that's been stored for a long time.  The capacitors will need reforming, which means, the gradual release of heat and hydrogen as they come up in voltage.  Doing it suddenly by applying full voltage means... 

Very likely, you have a hole in a board somewhere, and paper and foil confetti strewn about like a war zone. 

Tim

[Ysjoelfir]

Which board? That thing is still completely hand wired! And got some repair in the past as i found out today in the morning. one of the main filter caps seems to be dead, at least there is a new cap stuffed into the circuit.


And I just want to mention, that I did not turn it on, it was the seller and my uncle, who both have no idea of electronics. I know that you should never do that

[T3sl4co1l]

I know.  By board, I mean wooden boards...

Heard a story once, that a guy was working on a radio.  The main can went off, leaving an awful mess behind on the chassis, and pinning the can in the ceiling!  If he had been looking over the chassis at just the wrong moment...

Tim

[oldway]

This remember me the old times, my very began in electronics...I have repaired a lot of them but I don't have such old documentation anymore.
Be careful because chassis is live....one mains phase is directly conected to the chassis...
For security, you need an isolation transformer.
Heaters of the valves are connected in serie (PL series tubes with 300mA heating)
High voltage is generated from main voltage.
You have a voltage selector 220V/130V/110V. Look if it's not wrong selected.
In 220V, rectifier is a bridge rectifier, in 110V, it's wired as a voltage dubbler.
Sound is transformerless with special 600R loudspeaker.

As far as I remember, more often, we had to change bad power tubes: Horizontal : PL36 and PY81 (later, PL500 and PY88)
Vertical: PCL82 (later PCL85)
Sometimes, VHT transformer was bad, or the booster condensator (1600V)
If you have vertical deflection problem, change the electrolytic capacitor of the cathode of the PCL82/PCL85.

I found the service manual of the 21TX285A wich is almost the same as 21TD293A.
But that not easy to download.
http://diagramasde.com/blog/20095/21TX285A-pdf-PHILIPS-21TX285A.html

[drussell]

The gurus over at videokarma.org are very knowlegable...

Plus, someone over there might be able to point you to a proper schematic. 

[Ysjoelfir]

Heard a story once, that a guy was working on a radio.  The main can went off, leaving an awful mess behind on the chassis, and pinning the can in the ceiling!  If he had been looking over the chassis at just the wrong moment...

Yeah, I heard of that one, too! One of the main reasons you should never lean over your workpiece

This remember me the old times, my very began in electronics...I have repaired a lot of them but I don't have such old documentation anymore.

Ah, to bad But nice to know that there are still people around who have worked at those things and are willing to help out! Thanks!

Be careful because chassis is live....one mains phase is directly conected to the chassis...

I already noticed the lack of an input transformer, but I have to admit that I sometimes forget about those... (what is it called in english? In german it is "Allstromgerät", a device that runs either on DC or AC and therefore has no input transformer) ...things.

For security, you need an isolation transformer.

I have one and would never try any device without using it

Heaters of the valves are connected in serie (PL series tubes with 300mA heating)

I actualy like the P series tubes as they are sometimes realy cheap to get and of decent quality in great amounts available. Can't understand why there are that many people who hate those things..

High voltage is generated from main voltage.
You have a voltage selector 220V/130V/110V. Look if it's not wrong selected.
In 220V, rectifier is a bridge rectifier, in 110V, it's wired as a voltage dubbler.
Sound is transformerless with special 600R loudspeaker.

Thanks for those informations!

As far as I remember, more often, we had to change bad power tubes: Horizontal : PL36 and PY81 (later, PL500 and PY88)
Vertical: PCL82 (later PCL85)
Sometimes, VHT transformer was bad, or the booster condensator (1600V)
If you have vertical deflection problem, change the electrolytic capacitor of the cathode of the PCL82/PCL85.

I already noticed that the tubes in the horizontal stage are quite worn out with that leadflowers all over the glass (that brown smear stuff inside the glass, mostly at places where those little electrons can hit the glass instead of the anode ). I have a decent amount of all used tubes in there, so swaping them around shouldn't be a problem when I get to the point of actualy switching it on.
The booster Cap could be a problem, please take a look at the picture attached. There is some leakage spreading over the dust around the cap, looks like it shot some liquid out. I will examine that as soon as I get my air supply working. It seems to be the sticky kind of dust you see in devices used by smokers, so I won't start going around with a brush in there.

I found the service manual of the 21TX285A wich is almost the same as 21TD293A.
But that not easy to download.

thanks for that information, too! The website is indeed very crappy, but I sound the manual around the web. It is a bit different, but to start with a few measurements it should do the job.

The gurus over at videokarma.org are very knowlegable...

Plus, someone over there might be able to point you to a proper schematic. 

Thanks, I will post there, too!

[oldway]

It looks good.

This is already a previous repair.

[Ysjoelfir]

Yep, it looks quite decent. For the one euro I paid for the TV I guess I can't complain.

The repair you found is what I mentioned here:

I already found a leaky cap that was sealed by wax inside the high voltage cage by my first visual inspection.

And there is actualy another cap bodged over one of the metal can filter caps, the large black one at the lower left corner. I guess I have to replace both caps. I will try to disassemble those old ones, clean them out and place new caps inside to maintain the original look. Even though I have no Idea what I can replace those candy like caps with. I don't really want to use standard wima types, the red squares doesn't belong in there

[oldway]

For me, the capacitor I have showed in green is an electrolytic capacitor of 350 or 400V which has been added because one of the metal can capacitors of the power supply has lost his capacitance.
It is probably wired in parallel with the defective capacitor.

Some tips:
- We did not always have a VARIAC, nor isolation transformer to power the TV we were at repairing.
We did power the TV only during a few seconds , then we unplugged the TV and feel if any metalic can electrolytic capacitor was getting warm...a bad electrolytic capacitor is always getting very warm before he explode.
- The first thing to look is the tube filaments: do they glow ?
- the second one is to look if you have High voltage.
For this, we used a well isolated screwdriver and we were touching the anode (cap on the top) of the PL36 (line pentode).
If everything is ok, you have a spark of 2 or 3 mm.

[Ysjoelfir]

Hi everyone and sorry for the late response Since the TV is a side project I don't work at it all time.
Actualy I am still waiting for the registration at videokarma getting done, It said that an administrator has to manualy activate it, but since then (6 weeks...) there was no change. Andyes, I already tried registering again
I am also still missing an "original" circuit diagram for that chassis, since the already mentioned are quite simmilar, but not identical. I can work with those, but having the correct one would be nice...