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Old 19th Nov 2020, 12:28 am   #21
Clydeuk
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Default Re: Faulty CRT Computer Monitor

Checking the model number I see it is for the CPC+ range of home computers so will be a standard resolution CRT similar to those in portable TV's of the era. Even in the 90's when these weren't that old this problem was cropping up regularly. I think it is something to do with the composition of the wedges, probably a similar kind of thing to those rubber belts that turn to goo over a number of years. Some sets had grey wedges and I never saw this problem where they were used.

If you really value the monitor you could probably use a CRT assembly from a 14 inch portable TV, if you can find a good one. I know I did this with the earlier CPC monitors.
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Old 19th Nov 2020, 11:53 am   #22
Maarten
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Default Re: Faulty CRT Computer Monitor

The 'water' on the wedge might be an acidic byproduct of some decomposition.
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Old 19th Nov 2020, 1:54 pm   #23
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Default Re: Faulty CRT Computer Monitor

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Originally Posted by Clydeuk View Post
Checking the model number I see it is for the CPC+ range of home computers so will be a standard resolution CRT similar to those in portable TV's of the era. Even in the 90's when these weren't that old this problem was cropping up regularly. I think it is something to do with the composition of the wedges, probably a similar kind of thing to those rubber belts that turn to goo over a number of years. Some sets had grey wedges and I never saw this problem where they were used.

If you really value the monitor you could probably use a CRT assembly from a 14 inch portable TV, if you can find a good one. I know I did this with the earlier CPC monitors.
I've found someone round the corner from me with a grundig 14" tv so might go get that and see if I can use the tube off that.
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Old 19th Nov 2020, 9:07 pm   #24
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Default Re: Faulty CRT Computer Monitor

I’d be interested to see how you get on with this. I too own one of these and dread the day mine stops working.
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Old 19th Nov 2020, 9:14 pm   #25
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Default Re: Faulty CRT Computer Monitor

I went and picked it up. It has a Philips tube in it. Its working ok but I'm not convinced I'm going to be able to swap the tube over. I was hoping it might be a straight swap but not convinced. Need to clean it up, discharge and see what it's like. I guess worst case I just use this instead. Its the right colour case and is a good match for the computer.
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Old 19th Nov 2020, 10:58 pm   #26
Clydeuk
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Default Re: Faulty CRT Computer Monitor

Despite the dirty inside, that does look quite a bit newer than the monitor.

If it's in good working condition I would be inclined to keep it in one piece and use it as you say.
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Old 20th Nov 2020, 8:21 am   #27
1955APREN
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Default Re: Faulty CRT Computer Monitor

Looking at the 2 picture in thread 25 this the same set as the mastui 14r or 14t. Be careful if swopping over crt , at the back of my mind is a idea about heater voltage being different on these 14ins tube.
Can you give us the full crt No off the label on the crt .
regards Derrick

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Old 20th Nov 2020, 11:48 am   #28
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Looking at the 2 picture in thread 25 this the same set as the mastui 14r or 14t. Be careful if swopping over crt , at the back of my mind is a idea about heater voltage being different on these 14ins tube.
Can you give us the full crt No off the label on the crt .
regards Derrick
Thanks I'll get the tube number, I'm thinking its probably not worth swapping, it dates from about 1997 but would be interested if it's a straight swap or not if I decide to do it.

This is a nice TV and works fine via Scart so really it's more flexible than the old monitor, even the colour is a good match for the computer, the only downside is its mono and I don't have the remote for it.
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Old 20th Nov 2020, 1:10 pm   #29
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I’d be interested to see how you get on with this. I too own one of these and dread the day mine stops working.
It's not too late to take preventive action, i.e. removing the old wedges and glue, cleaning up and replacing them with other wedges from a different type out of a scrap set. Since the yoke needs to be removed and refitted, you should be prepared for some redoing of at least the dynamic convergence.
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Old 20th Nov 2020, 3:23 pm   #30
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Default Re: Faulty CRT Computer Monitor

I may (note: may!) still have the scan coils from a Matsui 1420b 14" I scrapped for another fault a few years back. You would be welcome to them.

However, it will be some months before I can access them. If you don't mind the wait and can hang on to your Amstrad it might be a way to revive it.

Meanwhile, perhaps other members could confirm compatibility between these two.
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Old 21st Nov 2020, 12:35 am   #31
Clydeuk
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I may (note: may!) still have the scan coils from a Matsui 1420b 14" I scrapped for another fault a few years back. You would be welcome to them.

However, it will be some months before I can access them. If you don't mind the wait and can hang on to your Amstrad it might be a way to revive it.

Meanwhile, perhaps other members could confirm compatibility between these two.
I can't say if they will be compatible but my gut says they will be.

The way I used to do it was to measure the resistance of the field coil windings and if they were fairly close I would do the swap, tweaking the height if necessary.

Nothing to lose in this case.
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Old 21st Nov 2020, 4:52 pm   #32
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Default Re: Faulty CRT Computer Monitor

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Originally Posted by ben View Post
I may (note: may!) still have the scan coils from a Matsui 1420b 14" I scrapped for another fault a few years back. You would be welcome to them.

However, it will be some months before I can access them. If you don't mind the wait and can hang on to your Amstrad it might be a way to revive it.

Meanwhile, perhaps other members could confirm compatibility between these two.
Hi Ben that would be great. I've got no issues waiting, the monitor was stored for over a year, it would be shame to scrap it if it can be repaired.
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Old 25th Nov 2020, 10:25 pm   #33
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Default Re: Faulty CRT Computer Monitor

Hi all, I decided not to break up the Grundig as it's a nice fully working TV and don't want to end up with two broken sets but I picked up a free philips set, it works but the tube itself has quite alot of scratches on the face so isn't good for much.

I've attached some pictures of the numbering on the tube and was hoping someone in the known might be able to tell me if this is a feasible swap for the coils.

Bit depressing to see this tube was made in the UK, probably make virtually nothing like this now, I guess the whole of Philips is a very different company now. Philips UK R&D once once just down the road from me in Redhill, the site bulldozed and is now a warehouse complex.
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Old 26th Nov 2020, 6:27 pm   #34
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Default Re: Faulty CRT Computer Monitor

The CRT label looks quite unfamiliar, modeled after the label used by their Taiwan CRT factory. If it didn't show UK on it I would have said it came from Taiwan, for sure.

The important part of the CRT label, the grey printing with the type number isn't quite readable. Could you take a close up picture of that?

Also, could you have a look if there's any white stamping on the bell of the CRT? And maybe a picture of the deflection yoke?
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Old 26th Nov 2020, 8:20 pm   #35
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The CRT label looks quite unfamiliar, modeled after the label used by their Taiwan CRT factory. If it didn't show UK on it I would have said it came from Taiwan, for sure.

The important part of the CRT label, the grey printing with the type number isn't quite readable. Could you take a close up picture of that?

Also, could you have a look if there's any white stamping on the bell of the CRT? And maybe a picture of the deflection yoke?
Here is the label on the tube, the writing is very feint.
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Old 27th Nov 2020, 10:53 am   #36
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Extra photos. I could see any white writing the bell.
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Old 27th Nov 2020, 11:41 pm   #37
Maarten
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Default Re: Faulty CRT Computer Monitor

Strangely, it's not manufactured by Philips, and I don't know why it says UK on the label. The manufacturer is almost certainly Chunghwa (CPT) of Taiwan. Did they have a factory in the UK? The TV set itself was made in Poland.

EDIT: apparently, they produced picture tubes in Glasgow up until 2004 then went into insolvency and ended in 2015. According to glassdoor they were still taking job applicants in 2012 but they already wound down operations. Possibly they had a sales office for their LCD products.The Taiwanese mother company still exists. Also see https://find-and-update.company-info...589/insolvency

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Old 28th Nov 2020, 8:22 pm   #38
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Strangely, it's not manufactured by Philips, and I don't know why it says UK on the label. The manufacturer is almost certainly Chunghwa (CPT) of Taiwan. Did they have a factory in the UK? The TV set itself was made in Poland.

EDIT: apparently, they produced picture tubes in Glasgow up until 2004 then went into insolvency and ended in 2015. According to glassdoor they were still taking job applicants in 2012 but they already wound down operations. Possibly they had a sales office for their LCD products.The Taiwanese mother company still exists. Also see https://find-and-update.company-info...589/insolvency
That is strange. Do you think it might have been made Chunghwa in Glasgow?

As for whether it will work in my old Amstrad monitor I might just try it, take the PCB and plug it in and see what happens. The TV has some sort of intermittent issue as it won't always switch on and the tube has a few scratches on the face so really I have nothing to lose.
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Old 30th Nov 2020, 7:54 pm   #39
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It is almost certainly made by Chunghwa in Glasgow. Philips did sometimes ask for custom labels on bought in CRTs. I've also seen "Philips" W76EKW tubes, made by Panasonic Germany (formerly known as SEL).

It might be good news for you, as the Chunghwa may be a closer match to the original tube. I'd try replacing the tube+yoke as a complete assembly first.
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Old 30th Nov 2020, 9:01 pm   #40
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It is almost certainly made by Chunghwa in Glasgow. Philips did sometimes ask for custom labels on bought in CRTs. I've also seen "Philips" W76EKW tubes, made by Panasonic Germany (formerly known as SEL).

It might be good news for you, as the Chunghwa may be a closer match to the original tube. I'd try replacing the tube+yoke as a complete assembly first.
Thanks Maarten, good idea I'll swap the tube and yoke over first to see how it performs before deciding if I swap the yoke onto the other tube. Just need to buy the parts for pcb now to repair that.
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