Changing Power Switch on Commodore 1702 monitor

[carlsson]

Generally speaking, I've tried serveral PAL CRT TV's as well as computer monitors (1) with computers and video games that output NTSC signals. All of them tend to sync to composite video, but not display any colour. I can't recall a case where the image was rolling or something like that, perhaps that is because PAL is 625 lines and the TV detects when a vertical retrace happens so it can display 525 lines from NTSC without issue except for the colour subcarrier is wrong? I don't know about the opposite case, but since adam242 mentioned adjusting vertical hold, perhaps there is more to it to display a 625 line PAL signal on a NTSC monitor than vice versa (and most of the time, the colour subcarrier still would be wrong).

 

(1) Mainly Commodore branded though we all know these are OEMs from variuos manufacturers with a C= logo slapped onto the front.

[shoestring]

I did the switch mod on a mega-drive recently for a friend who wanted to play sonic in NTSC.

 

We had video going into a philips CM8833, apart from the black and white picture the game played much better. The only solution was to use the RGB scart cable, beautiful picture. NTSC is much better for these types of games.

 

If you want NTSC and PAL in one monitor the Sony PVM is a good option, expensive though. I just recently picked up a PVM-9041QM that takes RGB, composite, component and svideo.

[erichenneke]

Hey, so I returned that 1702 and got a full refund .

 

I just found an amiga 1080 (exact model says "agi9xa 1080") locally for $100. So I wouldn't have to screw around with shipping!

 

Will this amiga 1080 hook up to atari 8bits easily, and if so, is it a good one for $100?

 

Next question would also be about whether it can do ntsc AND pal or not?

 

Thanks! !

Eric

[shoestring]

It's an NTSC monitor made by Toshiba. I've never seen a Commodore branded monitor than can handle both ( NTSC & PAL ) in colour. It should be able to to sync up with a PAL signal but you won't get any colour. If you want a monitor than can do both in colour then look at the Sony PVM series.

 

It will work fine with your Ataris. It can handle RGB, Composite and Separate Y/C.

 

https://gona.mactar.hu/Commodore/monitor/schematics/1080A_Color_Monitor_Service_Manual_3140041-02_With_Schematic.pdf

Edited November 11, 2018 by shoestring

[Mathy]

Hello Eric

 

NTSC only, according to this page.

 

Sincerely

 

Mathy

[erichenneke]

thanks all. I bought the Amiga 1080.

 

It looks fantastic, especially on my 130XE.

 

Looks really good on my 800XL as well.

 

Unfortunately, as expected, it only does PAL in B&W though.

 

I haven't done any of the chroma mods to my 800XL yet, so I am sure that's why the 130XE looks better. Of course, my 130XE always looks better than my 800XL regardless of what monitor, because I have always just used regular composite Yellow/White/Red cables and both systems are stock.

 

Sounds like I need to start doing some mods or at least a new cable to get the best out of this Amiga 1080 monitor.

 

-Eric

[shoestring]

I have the same issue with my NTSC Atari 800. I cannot get a decent picture on the LCD or colour on my Commodore 1084S so I bought a PVM.

 

You might find that the 800xl will look even better than the XE after the mods. The XE suffers from vertical banding in stock machines.

 

Your might have one of the machines made in Hong Kong that had the wrong value resistor installed ( 390ohms instead of 100ohms ) which caused signal impedance in the video output to be mismatched resulting in a blurry screen. They fixed that when they moved the production to Taiwan.

 

 

Once you replace that resistor with a 75ohm and do the rest of the mods, the display comes to life. You could also get yourself a UAV upgrade.

Edited November 12, 2018 by shoestring

[erichenneke]

I have the same issue with my NTSC Atari 800. I cannot get a decent picture on the LCD or colour on my Commodore 1084S so I bought a PVM.

 

You might find that the 800xl will look even better than the XE after the mods. The XE suffers from vertical banding in stock machines.

 

Your might have one of the machines made in Hong Kong that had the wrong value resistor installed ( 390ohms instead of 100ohms ) which caused signal impedance in the video output to be mismatched resulting in a blurry screen. They fixed that when they moved the production to Taiwan.

 

 

Once you replace that resistor with a 75ohm and do the rest of the mods, the display comes to life. You could also get yourself a UAV upgrade.

Thanks for the info. I have multiple 800XL's, but this is the one that's currently "on the desk top". Sure enough, it says "Made in Hong Kong" underneath. I'll check out that resistor situation when I get a chance.

 

Yes, I do notice the banding on the 130XE. It's like I need to turn the brightness down just a tad more than I'd like to in order to get rid of those lines showing. That is a bit annoying.

[RangerG]

The power switch fails on the 1084 model, but the 1702s tend to be much better (when it comes to power switches).

[shoestring]

Replaced the switch in mine very recently. There's a guy selling them on eBay. Not cheap, had to do some minor adjustments to get it to fit on the PCB.

 

From now on I just keep the switch in the on position to avoid the same issue and power the monitor up via the mains.

Edited February 19, 2019 by shoestring

[erichenneke]

Clearly very common on the 1702. I recently bought another one ( this one works great!). But the power switch is also broken.

At least this one is broken in the "on" position. So I just plug/unplug each time.

 

 

The switch on my Amiga 1080 monitor works fine though...but I am using the plug/unplug method with it anyway just to avoid it breaking too.

[youxia]

Probably bit off topic, but I was reading an old mag today and saw this:

 

 

Love that hand drawn cable schematic

[ethanterry]

Hello! I hope this thread isn't too dead to resurrect. I'm going through a similar situation as OP: received my monitor in the mail, power switch broken- the stem was brittle and snapped off, and in attempting to repair it I completely destroyed the old switch. Does anyone know where I can find that switch assembly, or one that will replace it? I still have the trapezoidal grey button, I just need the switch itself. A web search for the part number CEX40097-002 turns up nothing for sale (minus one US electronics parts dealer that contacted me after I ordered that it's no longer available.) 

 

If there's a comparable part, I'd pick one up right away. Even if it requires modification. And if anyone is parting out a busted 1702, let me know. I'll pay you whatever you want!