Microvitec Cub 2030 (with broken tube neck).

[tetlee uk]

Originally Posted by paulsherwin

We shouldn't mislead the OP though. This is going to be a difficult repair for anyone without lots of experience with CRT colour TVs and appropriate workshop facilities. It's not just a question of removing the old tube and screwing in a new one.

Of course, if the OP has access to a competent professional repairer and is prepared to bear the cost then a repair is perfectly possible.

I have to admit I really don't know just how good my local repairer is, I think he does mainly specialise in audio equipment but he does televisions as well. It works well that he is very local to me and he did suggest with a new tube he would be able to repair it, but I would not be wanting to invest too much money into a replacement screen just incase.

I hope that all makes sense. As mentioned if it wasn't for the rarity and versatility of the thing it almost certainly wouldn't be worth bothering with.

[Nickthedentist]

Originally Posted by paulsherwin

It's not just a question of removing the old tube and screwing in a new one.

True! But it's not rocket science and should be MUCH easier than with older tubes. I think the tube and yoke come as a pre-converged assembly, but I stand to be corrected if I'm wrong.

[Welsh Anorak]

You can stand proudly uncorrected, Nick!

It is an easy fix, but the 'new' tube will need the A1, focus and greysacle setting up which, although not difficult, might prove a little daunting if you've no experience of TVs

Tetlee - it would be worth posting a 'wanted' post on the forum - you never know. It will need to be exactly the same type - A51-590. Although it's possible to substitute tubes, that's something you really don't want to do.

Incidentally, try a post on a gaming froum as it appears some Hantarex 20" monitors used this tube.

[Cobaltblue]

He already has a wanted post as linked in post #14 in fact it was his first post.

He also has a local repairer.

Cheers

Mike T

[Welsh Anorak]

Sorry - should read all the posts!

However I remember there's a member who has an AVS2000 whose TV section has died. ISTR he was thinking of removing the TV section and replacing it with a modern TV. As far as I know this will use an A51-590. Might be worth a message?

Here's the thread:- https://www.vintage-radio.net/forum/showthread.php?t=217348&highlight=avs2000

[tetlee uk]

Thank you again guys, I have been searching for the aforementioned AVS2000 but haven't seen any for sale currently.

I just clicked on the link above but the link is dead for me, I will try a forum search in a minute. I guess it would depend what was the issue with his tv whether that tube would be any use to me.

If anyone happens to know any other specific sets that carried this tube that would be super helpful, it's a bit of a pain as obviously without opening a set the seller will be highly unlikely to know what tube is inside it.

[Cobaltblue]

Yes that link is broken I will se if I can fix it.

Try link now.

Cheers

Mike T

[tetlee uk]

Originally Posted by Cobaltblue

Yes that link is broken I will se if I can fix it.

Try link now.

Cheers

Mike T

Thanks Mike & Glyn, I actually found it through the search and have just sent him a message. Will update here if I have any joy, any other avenues or potential donor recommendations would be brilliant

[slidertogrid]

I agree with what others have said, it is a simple job to replace the tube like for like. Anyone who calls themselves a "repairer" should find it a doddle. As far as setting the greyscale, focus and first anode voltage again a competent repairer should be able to do it in minutes. If not I'm sure the advice available here will soon help set it up. The monitor is well worth saving and no doubt a tube will turn up eventually just put it to one side until one does...

I sometimes see sets dumped by the skip at our local auction house. A Ferguson TX9 20" will have the correct tube as will some Panasonic models. I'll keep an eye out. There was a TX9 dumped not so long ago - they are still out there.

[Bobdger]

Try looking for a Pye or Phillips 20" KT3 they used that tube. The few that I have seen in the last year have all had good tubes. Bob

[Welsh Anorak]

Might be wrong, but ISTR the 20" TX9 was fitted with the A51-580 which is different. However some TX100 20" sets used the 590.
Bob - I thought, the KT3 used the A51-570 which (in my experience) lost emission quite early on. The KT4 fared better but again it's an A51-570.

I thnk the Bush/Toshiba T24 used an a51-590 (or a close equivalent) but these are thin on the ground.

Unfortunately manufacturers swapped suppliers during production runs and modified their chassis to suit. AFAIK the Fidelity 20" only used the -590.

There is a (vastly overpriced) AVS1600 on eBay and Facebook at the moment - no use to you as it's the 16" version, but they are out there.

[tetlee uk]

Thank you all once again. I will definitely be keeping hold of this set for some time now as you've all re-ignited my glimmer of hope once more, it's nice to be feeling a bit more positive about my chances. It would sure make the set feel extra special if it could be brought back to good.

I suppose the best thing I can try and do for now is compile a list of those sets suggested as suitable donors. There are 2 or 3 that have since been doubted so I will exclude those for now as would hate to buy a set and find it has the wrong tube.

So let's see what we have so far....
Amstrad AVS2000
Fidelity 20"
Philips TX100 20"


With the following being possible but with doubts...
Pye or Phillips 20" KT3
Ferguson TX9 20"
Bush/Toshiba T24

All these searches seem dry in both any live, or even competed listings but still useful.

If anybody knows of any other potential or better still confirmed Mullard A51-590X tube that would be fantastic.

Thanks again.

[Maarten]

I think the Philips KT3 chassis used A51-570X tubes which are probably not compatible.

Originally Posted by paulsherwin

We shouldn't mislead the OP though. This is going to be a difficult repair for anyone without lots of experience with CRT colour TVs and appropriate workshop facilities. It's not just a question of removing the old tube and screwing in a new one.

Of course, if the OP has access to a competent professional repairer and is prepared to bear the cost then a repair is perfectly possible.

He has access to a repair shop, but also swapping a tube is not that complicated compared to most TV repairs (as long as you make room, ideally 4 times the frontal area of the set, and work meticulously). It's mostly a mechanical job, not much electronics apart from maybe soldering some wires. As long as the deflection yoke is the same and stays with the tube, it might work without adjustments or only a few simple ones. If the yokes are different, the yoke needs to stay with the chassis. In that case, swapping is still not that complicated, but setting it up just right does require some experience or willingness to confront a learning curve.

In my opinion it's mostly a scenario of finding a tube, and then take it from there.

[Refugee]

I used to fix VGA screens back in the day for sale at flea markets and used to swap several tubes per week. The line scan coils pretty well always worked. The frame coils were driven by a frame scan chip that was either 24 volts HT or 12 volts HT. It was a matter of going through the ones with fried power supplies or duff loptys with an ohm meter.
A check in the manual for the donor set would be in order before obtaining it.

[tetlee uk]

Originally Posted by Welsh Anorak

Sorry - should read all the posts!

However I remember there's a member who has an AVS2000 whose TV section has died. ISTR he was thinking of removing the TV section and replacing it with a modern TV. As far as I know this will use an A51-590. Might be worth a message?

Here's the thread:- https://www.vintage-radio.net/forum/showthread.php?t=217348&highlight=avs2000

Just an update to this potential lifeline. I messaged the OP of that thread, he kindly replied but that tv had already been dumped, although he described that his screen had speckles inside and a crooked board anyway so probably non-salvageable as it happened.

The search continues.

[tetlee uk]

Guys, I think I have just spotted a possible contender. I'm sure somebody mentioned this music centre.

https://ebay.us/m/fD7m4f

The seller mentions it 7.7" screen but just looking at the pic I'm sure that is a mistake.

Not too far from me.

Any thoughts?

Cheers again. I'm still actively looking and hoping.

One issue is they have an extremely ambitious buy it bow, and a reserve on auction so that could be way off the mark aswell.

[nigelr2000]

Looks like an AVS1600 to me which has a 16 inch screen

[tetlee uk]

Originally Posted by nigelr2000

Looks like an AVS1600 to me which has a 16 inch screen

Ah, thanks so much for the reply.

[Welsh Anorak]

I tend to agree, but a quick message to the seller would reveal the model number - it will have a 20 in the number if it's correct for you.
If there is no label then mention it's the diagonal measurement of the screen that is the correct one.

[Paul Stenning]

Please be aware of the eBay rules. We will allow discussions about whether the item in post #36 has a suitable tube or not, but nothing else about that listing, seller or eBay etc. One post edited.