My Issue 2 continuing problems and Issue 6s fixed

[redgatemodels]

This is what I get on the big TV

So pretty much the same, without the glitching. Looks like the old caravan TV has a problem with it's RF input ...

[1024MAK]

Well, it’s at least six colours

I may have asked this before, so forgive me, what test gear do you have? Do you have, or have access to a ‘scope?

What voltage do you get on ULA pins 15 and 16 with a white screen (border and text area white)?

What voltage do you get on pins 2 and 4 of IC14 (LM1889)?
Also confirm the DC voltages on pins 14, 15, 16, 12 and 3.

I presume IC14 is soldered in place rather than in a socket?

Mark

[redgatemodels]

Best I can get with this Comp mod pcb

is this

turning the vr1 trimmer goes from yellow tinge (PAL) to blue (SECAM)

Can't get white

[1024MAK]

VR1 and VR2 kinda interact with one another.

Mark

[redgatemodels]

I don't have a scope but can get the voltages, LM1889 is soldered

[redgatemodels]

What voltage do you get on ULA pins 15 and 16 with a white screen (border and text area white)? 1.8v, 1.68v

What voltage do you get on pins 2 and 4 of IC14 (LM1889)? 5v, 4v
Also confirm the DC voltages on pins 14, 15, 16, 12 and 3. 11v, 11v, 11v, 11v, 4.4v


Mark

[redgatemodels]

would it be worth swapping out c65?

[1024MAK]

It’s unlikely that it would have degraded so badly that it would cause this. But yes, you could try.

Mark

[redgatemodels]

are the voltages OK?

[1024MAK]

I’ll be busy until this evening, sorry.
But at a glance, no.

Mark