TV with weak colour

B

b

Guest
I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
.. is this likely to be something like a low voltage to the RGB
stage,or something more serious?

-B
 
In article
<d66fed69-3ff3-420b-b891-c50974d9cb8f@k36g2000pri.googlegroups.com>,
b <reverend_rogers@yahoo.com> wrote:
I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
. is this likely to be something like a low voltage to the RGB
stage,or something more serious?
What happens if you drive it with an RGB signal?

--
*Always borrow money from pessimists - they don't expect it back *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
"b" <reverend_rogers@yahoo.com> wrote in message
news:d66fed69-3ff3-420b-b891-c50974d9cb8f@k36g2000pri.googlegroups.com...
I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
. is this likely to be something like a low voltage to the RGB
stage,or something more serious?

-B
If the A1 control is set wrongly, some of the older CRT types can look
'washed out'. Sometimes, beam limiter problems can give the same effect. A
fault in the ACC circuitry will do it, and sometimes, a mishapen sandcastle
pulse, which used to be quite common back then. Often down to a resistor in
the HOP stage, where the pulse is 'constructed', having gone high.

Arfa
 
On Tue, 30 Dec 2008 04:03:46 -0800 (PST), b
<reverend_rogers@yahoo.com>wrote:

I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
. is this likely to be something like a low voltage to the RGB
stage,or something more serious?

-B
Let's see you say it works WELL but has no/little color?

Get service literature with voltage and video/chroma waveform test
points. Get a DVM and a scope. It's not likely that you'll find the
problem without these basic tools unless you want to heat and cool
components while the set is on the bench live.
 
On 30 dic 2008, 15:46, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
"b" <reverend_rog...@yahoo.com> wrote in message

news:d66fed69-3ff3-420b-b891-c50974d9cb8f@k36g2000pri.googlegroups.com...

I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
. is this likely to be something like a low voltage to the RGB
stage,or something more serious?

-B

If the A1 control is set wrongly, some of the older CRT types can look
'washed out'. Sometimes, beam limiter problems can give the same effect. A
fault in the ACC circuitry will do it, and sometimes, a mishapen sandcastle
pulse, which used to be quite common back then. Often down to a resistor in
the HOP stage, where the pulse is 'constructed', having gone high.

Arfa
I finally dug this set out again today and it did seem as if the G2
was a bit high, so I lowered the SCREEN control slightly on the Line o/
p tranny and that gave a far more natural colour. Haven't tried it
with RGB source, as didn't have one to hand. set seems fine now ,
cheers,
B.
 
"b" <reverend_rogers@yahoo.com> wrote in message
news:9a755f12-6546-4a1a-bae1-c6b4342ab351@s1g2000prg.googlegroups.com...
On 30 dic 2008, 15:46, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
"b" <reverend_rog...@yahoo.com> wrote in message

news:d66fed69-3ff3-420b-b891-c50974d9cb8f@k36g2000pri.googlegroups.com...

I have a late '80s vintage Philips CP110 Tv , which works well, but
the colour is weak, even with the saturation control set to full the
picture is only just more 'colourful' than B&W!
. is this likely to be something like a low voltage to the RGB
stage,or something more serious?

-B

If the A1 control is set wrongly, some of the older CRT types can look
'washed out'. Sometimes, beam limiter problems can give the same effect.
A
fault in the ACC circuitry will do it, and sometimes, a mishapen
sandcastle
pulse, which used to be quite common back then. Often down to a resistor
in
the HOP stage, where the pulse is 'constructed', having gone high.

Arfa

I finally dug this set out again today and it did seem as if the G2
was a bit high, so I lowered the SCREEN control slightly on the Line o/
p tranny and that gave a far more natural colour. Haven't tried it
with RGB source, as didn't have one to hand. set seems fine now ,
cheers,
B.
I'm not familiar with the model - and slightly out of touch with TVs in
general - but having considerable experience in TV service in the distant
past, I can tell you that colour saturation has nothing to do with A1 or A2
controls - which only affect brightness or 'grey-scale' settings. Look for
the chrominance amplifier circuitry, that is where the problem is likely to
be.
 

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