Commodore 1084S no image from any ext. source, but HV is present

[Quibus]

Hi All,

I was given a Commodore 1084S (Philips-built) monitor, that I would
like to get in working order again for my vintage Atari 800XL. It is a
quite versatile monitor, as it has CVBS, L/C, RGB analog and
RGB-digital inputs.

It displays no picture from any of the inputs. I tried a CV and a RGB
analog source. It _does_ have HV (I can hear and feel the static on
the front of the tube), the filaments in the neck of the tube glow up
and the powerled is on. Also the screen flashes like it should when I
switch it off.

I have already (completely) resoldered the base PCB, the neck PCB and
the PSU-board, but to no effect. I have also checked the voltages on
the PSU-board, and they are all present.

Any suggestions on how to get this monitor in working order again? Is
this a typical fault with this brand and type?

Thanx in advance, Quibus.

 

[that parrot chap]

Hi All,

I was given a Commodore 1084S (Philips-built) monitor, that I would
like to get in working order again for my vintage Atari 800XL. It is a
quite versatile monitor, as it has CVBS, L/C, RGB analog and
RGB-digital inputs.

It displays no picture from any of the inputs. I tried a CV and a RGB
analog source. It _does_ have HV (I can hear and feel the static on
the front of the tube), the filaments in the neck of the tube glow up
and the powerled is on. Also the screen flashes like it should when I
switch it off.

I have already (completely) resoldered the base PCB, the neck PCB and
the PSU-board, but to no effect. I have also checked the voltages on
the PSU-board, and they are all present.

Any suggestions on how to get this monitor in working order again? Is
this a typical fault with this brand and type?

Thanx in advance, Quibus.

I have the manual for the 1084S-P if you need any info?

 

[Franc Zabkar]

I was given a Commodore 1084S (Philips-built) monitor, that I would
like to get in working order again for my vintage Atari 800XL.

http://www.devili.iki.fi/Computers/Commodore/C1084S/schematics/


- Franc Zabkar

 

[Quibus]

http://www.devili.iki.fi/Computers/Commodore/C1084S/schematics/


- Franc Zabkar

Hi Franc,

I had already found this schematic, and noticed that the layout
differs a bit from my 1084S. I also have the schematic for a 1084P-S
and a Philips 8833, and these differ as well.

Thanx anyway for your reply.

Grtz, Quibus

 

[Quibus]

I have the manual for the 1084S-P if you need any info?

Hi Kev,

I have searched the net and found a number of schematics for the 1084,
so I probably already have the manual you mention. However, every
schematic I found differs a bit from my 1084S. Thanx anyway for your
reply.

Grtz, Quibus

 

[Lenny]

I had one some time ago with a bad demodulator chip. Don't remember
the number but trace back from the CRT and you'll run into it.
Lenny Stein, Barlen Electronics.

 

[Lawrence]

I've got quite a bit of Amiga stuff here. One of my monitors had a bad
switch on it. It was the switch for changing between RGB input and
video/audio input. Have you tried your audio input? I don't recall off the
top of my head which model of 1084 it was but if you email me directly
then I'll see if I can remember which of my monitors it was and I'll get
back to you with more info.

Lawrence

 

[Quibus]

I had one some time ago with a bad demodulator chip. Don't remember
the number but trace back from the CRT and you'll run into it.
Lenny Stein, Barlen Electronics.

Hi Lenny,

Thanx for your reply.
Were the symptoms your 1084 showed the same as mine has? Could the
chip you mention in your recollection possibly be a TDA3505?

Grtz, Quibus