Commodore 1084ST

[Gary C]

Does anyone have a service manual or circuit diagrams for this monitor ? or information if its a clone of another monitor type ?

Unlike the majority of 1084's, its not a Philips CM8833 clone by the looks of it.

 

[MiaM]

Afaik the two OEMs for 1084 monitors were Philips and Daewo.
Try looking for something like 1084-D or 1084S-D or similar model names.

 

[Gary C]

The ST is a Likcom unit by the looks of it and there doesn't seem to be a manual.

 

[daver2]

I spent ages looking for a manual for this beast also - with no luck.

Dave

 

[MauriceH]

To investigate what ,who produced the PCB is to close look at the components and markings on PCB.
All little details to be investigated every label ,every number

If a technical problem with monitor, keep in mind most have same setup design.
use datasheets from ICs for information.
Use known schematics as a guideline.

 

[Torch]

Is it possibly the same as the Magnavox 1CM1352 ?

I was never able to locate a PDF for my 120 volt US model. I eventually found and bought an original manual.
I did find a PDF for for the 240 volt model in some forgotten corner of the internet. It was so close, but many component values were way off.

A quick Google search for the ST still comes up with endless 1084 versions, and I don't feel like playing detective again.

As a quick identifier, my Magnavox has the push button power switch in the rear. I did see an ST with a rocker switch, but considering the push switch is so problematic, it may have been replaced on that monitor.

 

[Gary C]

Going to have to put them down as spares. Failed deflection coils in one monitor and other monitor singing with possible flyback fault. Without a detailed spec or actual spares from the same monitor, Im just guessing.

 

[MiaM]

Is it possibly the same as the Magnavox 1CM1352 ?

Philips owned Magnavox at this time (acquired in 1974) so if it had been the same as a Magnavox model it would had been similar to the European 220-240V models branded either as Philips or any of the OEMs.
(I think that the "1084-P" design was used also for a Magnavox branded monitor but not for a Philips branded monitor, but the electronics are afaik more or less the same as the CM8833 and it's similar siblings (CM8802 and whatnot).

 

[Torch]

Philips owned Magnavox at this time (acquired in 1974) so if it had been the same as a Magnavox model it would had been similar to the European 220-240V models branded either as Philips or any of the OEMs.
(I think that the "1084-P" design was used also for a Magnavox branded monitor but not for a Philips branded monitor, but the electronics are afaik more or less the same as the CM8833 and it's similar siblings (CM8802 and whatnot).

The 1CM1352 internals are vaguely similar to the CM8833. However, it's like the old saying, close enough only applies to horseshoes and hand grenades. The easily available CM8833 tech manual was of no use to me for troubleshooting.
There are even differences between CM8833 models. My 1CM1352 doesn't use the same flyback as the CM8833 mk1, but it does use the same HR7533 as the mk2 (unfortunately, the rest of the internals are not the same as the mk2).

 

[MiaM]

Interesting!

Worth noting is that the internal/full name of Philips products also tend to have a slash and a 2-3 additional digits/letters, which identifies products that technically differ internally but are advertised as the same as they have about the same specs.
For example this CM8833 service manual mentions /00G, /00S, /05G, /05S and /16G.
Btw thinking about it, a potential reasons for difference between Magnavox branded monitors and NTSC Commodore branded monitors on one hand, and Philips branded monitors and PAL Commodore branded monitors might be related to supply chain issues or whatnot? I.E. tolls, shipping costs or just different price points for things like deflection coils in North America v.s. Western Europe back in the days. I bet that Philips made the deflection coils themselves for the European market, but even if they made them themselves it might had been more expensive to use their own ones than to buy from a third party for the monitors that I assume were assembled in North America. The same might had applied to for example the high voltage transformer / cascade assembly and other parts that would have had a fairly high cost and/or would be expensive to ship due to it's size/weight.
The semiconductors Philips made would probably not had had that much price difference in Europe v.s. in North America though I think?
Btw a semi related tangent: What is the general opinion in North America about these Philips/Magnavox monitors when it comes to composite and s-video signals? Over here in Europe I would rate them as above average but not the absolute top notch. (In particular at the time Bang&Olufsen's patent on CTI, Color Transient Improvement, were afaik only third party licensed to Grundig. Eventually Philips and probably others too also implemented it, but I've never seen any signs of these CM8833 monitors and their siblings to have CTI).

 

[vwestlife]

Magnavox had the Color Monitor 40, Color Monitor 80, and RGB Monitor 80 all in the same 1084-style cabinet. The differences were in the dot pitch of the CRT, whether or not it had an anti-glare coating, and the inputs provided (composite, luma/chroma, analog RGB, and/or digital RGBI). Many had an artifact of where a SCART jack would go, but no North American versions ever had it installed.

 

[MiaM]

Magnavox had the Color Monitor 40, Color Monitor 80, and RGB Monitor 80 all in the same 1084-style cabinet. The differences were in the dot pitch of the CRT, whether or not it had an anti-glare coating, and the inputs provided (composite, luma/chroma, analog RGB, and/or digital RGBI). Many had an artifact of where a SCART jack would go, but no North American versions ever had it installed.

The unused knock-out for a SCART connector was a thing in Europe too. I don't know what was the reason for some of the monitors having a SCART connector and some having a 6-pin DIN for analogue RGB. Maybe the Philips branded ones used SCART and the Commodore/OEM ones used the 6-pin DIN connector?
Or maybe it was due to the SCART connector being less sturdy, or at least more prone to falling out, and thus it was used for consumer oriented monitors while the DIN connector was used for more professional use cases?