Undoing an LCD monitor upgrade back to CRT

[Mr Matt]

The diagonal of the bezel cutout is 48cm so you need a 20" TV or arcade monitor (20" CRTs have 19" screens). 20" PC monitors exist but are quite rare. The common size is 19" which means the screen is only 46cm (19" CRTs have 18" screens). Also they are flatter and may not sit well on the bezel (gaps).

I think I need a 19" TV CRT with 18" viewable screen because the diagonal of the bezel is 19". I've got a Hantarex A51 here but it's too big because the tube is 20" and viewing screen is 19". It's from a Goliath cab and I replaced the tube with a 20" TV tube. So a 20" TV would be too big for this bookie's cab.

So I guess I need a 19" CRT TV with 18" viewable (?).

I'm now back to the Pro-Electron vs WTDS issue again...

 

[M K L]

I thought bezels were supposed to cover the black borders and let you see just the viewable screen?

If it's possible to remove the bezel you could put it against the Hantarex tube and see if it fits well.

By the looks of it, the sides are too straight and the corners too square for a 20".

If it turns out to be for a 19" (18" screen) your only chance is a PC monitor as that size was almost never used for TVs.

This looks like the same cab modified for a bigger monitor:

https://forum.arcadeotaku.com/viewtopic.php?f=6&t=41904&p=530764#p530764

M K L2020-09-20 13:25:46

 

[Mr Matt]

I'll take a look later. I expected the whole screen to fit inside the bezel and the curvature of the tube to be more pronounced.

I've got a 20" TV I can maybe use in that case, however it's an A51 with square corners. Seem to remember this technically makes it an actual 21" tube though.

 

[M K L]

OK now I see there is a separate sub-bezel. I thought they were one thing as they're both black on your cab.

Seeing as the big bezel has curved sides and round corners and that the diagonal measures 48cm, it's clearly for 20" CRTs where the tube number starts by A48 or A51 (like A51-421X not A51EBV13X01 and similar). If the diagonal of the sub-bezel is 46cm it's for adapting 19" CRTs where the tube number starts by A46 (very rare) or M46 (very common = PC monitor).

The bezel sits on the glass and only lets you see the viewable screen.

M K L2020-09-20 14:26:31

 

[Mr Matt]

I'll try the Hantarex A51-421X tube that I have for a fitting.

I have no chassis but I have the TV PCB.

Does this actually work?
https://youtu.be/MmiBhLUkKEM

 

[Kev A]

Does it have a scart input? Much easier of it does

 

[tb2000]

I have a few vga monitors in the right frames out of these type of quiz cabs. Let me know if you want one, we can probably sort something out. They're either Tatung or Pentranic, depends on what they came out of originally. Like MKL says above, these are usually use M46 crts (that might be a flat crt i'm thinking of, I think I have a few with A48/M48 non-flat crts).

 

[Mr Matt]

Does it have a scart input? Much easier of it does

Yeah it has a scart input. Do I need a converter or can I wire the JAMMA video into the scart?Mr Matt2020-09-20 15:49:35

 

[Kev A]

You can make your own adapter, but it needs resistors and stuff But the adapters are cheap to buy and have adjustments for the rgb signals etc, thats what I used.

Worth bearing in mind if Tony hant got anything suitable. Tbh that would be the easiest way.

 

[Mr Matt]

You can make your own adapter, but it needs resistors and stuff But the adapters are cheap to buy and have adjustments for the rgb signals etc, thats what I used.

Worth bearing in mind if Tony hant got anything suitable. Tbh that would be the easiest way.

I found this earlier which is what I'd use to keep it neat.

https://www.ebay.com/itm/293021554213

Does anyone in the UK make or sell these?

 

[Kev A]

Not sure. Got mine from the fella that was knocking out superguns and rgb-scart adapters for a fiver a couple of years ago. Although a few people never recieved their orders from him.

 

[John Bennett]

I'll try the Hantarex A51-421X tube that I have for a fitting.

I have no chassis but I have the TV PCB.

Does this actually work?
https://youtu.be/MmiBhLUkKEM

f**king hell, that's not the way I thought someone would go about finding the RGB lines.

No need to lick your fingers and stick them on a live chassis anyway, as we've got SCART, unlike the USA.

You can get away with just resistors for 95% of games, as it's just about dropping the TTL-level JAMMA video signals to 75 ohm TV voltage levels, but anything with an op-amp for the video is better as some boards can't drive the increased load, so the picture goes really dim as the signals collapse. I was going to make something up for me* and I might have some spares if you're not in a rush, but I'm sure there's plenty of 'superguns' out there that'll do the job (the blue thing is resistors-only, so OK in most cases but not all).

*I've always used TVs, but been using a stripboard lash-up for the amplifier circuit for too long.

 

[Mr Matt]

I'll try the Hantarex A51-421X tube that I have for a fitting.

I have no chassis but I have the TV PCB.

Does this actually work?
https://youtu.be/MmiBhLUkKEM

f**king hell, that's not the way I thought someone would go about finding the RGB lines.

No need to lick your fingers and stick them on a live chassis anyway, as we've got SCART, unlike the USA.

You can get away with just resistors for 95% of games, as it's just about dropping the TTL-level JAMMA video signals to 75 ohm TV voltage levels, but anything with an op-amp for the video is better as some boards can't drive the increased load, so the picture goes really dim as the signals collapse. I was going to make something up for me* and I might have some spares if you're not in a rush, but I'm sure there's plenty of 'superguns' out there that'll do the job (the blue thing is resistors-only, so OK in most cases but not all).

*I've always used TVs, but been using a stripboard lash-up for the amplifier circuit for too long.

Thanks! I think I've now been convinced to go back to the original plan and use a CRT TV in the cab. I do also have a JAMMA CRT cab and it looks so much better than the couple of LCD cabs I have, I think also the 60in1 runs better in CGA than VGA, so that's definitely the best option for this cab.

I'll source another 20" TV and get this JAMMA 2 Scart PCB, which seems decent and tidy.

https://www.ebay.co.uk/itm/293021554213

Cheers everyone for the advice.

Mr Matt2020-09-20 22:06:05

 

[Jamesdcat]

I have an original monitor and frame from this machine if you are interested.

 

[Mr Matt]

I have an original monitor and frame from this machine if you are interested.

Is it a 20" arcade CRT?

 

[Jamesdcat]

It is original monitor, crt touchscreen monitor 19 I think.

 

[Mr Matt]

It is original monitor, crt touchscreen monitor 19 I think. 

I havent seen the original monitor before. How is it powered?

I'll have a look at the PSU I'm using but I dont think its man enough for an arcade CRT. Probably the easiest solution is using a TV set with the spare mains cable that's inside(?).

Cheers

 

[ZedEx48K]

I havent seen the original monitor before. How is it powered?

Kettle lead.

ZedEx48K2020-09-21 09:38:05

 

[Mr Matt]

I havent seen the original monitor before. How is it powered?

Kettle lead.

Oh OK. That would work. I don't need the touchscreen part of it but would be nice to get an original monitor back into it.

Is there any screen burn? Is it CGA or VGA?

How much and where are you?

Mr Matt2020-09-21 11:44:51

 

[Jamesdcat]

Hi I am near Leeds, the screen is VGA and has minimal screen burn, this came as part of a project machine so I have not used it plugged in and took this pic, £20?