New build 3b yellow tint

[lostretrotapes]

Got a problem can't seem to find the fault for. Am making a new 3B Speccy using PABs board, all good apart from the screen has a yellow tint to it. Have checked and replaced LM1889 and 12v is going to pin 14. Also changed just in case TR8 and 9.

Have swapped ULA with a tested one and tested this one in a working Spectrum so can rule that out.

[hellraiseruk]

Daft question, but have you tried another tv? Speccies don't play nice with some sets....

JD

[1024MAK]

The colour is determined by the difference between IC14 pin 2 and pin 3 AND between pin 4 and pin 3.

So with a completely white screen, please measure the DC voltage on IC14 pins 2, 3 and 4.

Also, with the power off, check/test
R56,R63, R74, R75, R76, R77, and R78.
Also check C52, C53, C68, C69, C70, C71 and C76,.

LK2, LK3, and LK4 must NOT be fitted.

What do the other colours look like?

Mark

[lostretrotapes]

Other colours look fine, it is just like a yellow tint overlay is on the screen.

Have checked with 2 TVs and same issue, other spectrums on the TVs work fine.

Will check that list of caps and resistors, thanks!

[lostretrotapes]

The colour is determined by the difference between IC14 pin 2 and pin 3 AND between pin 4 and pin 3.

So with a completely white screen, please measure the DC voltage on IC14 pins 2, 3 and 4.

Also, with the power off, check/test
R56,R63, R74, R75, R76, R77, and R78.
Also check C52, C53, C68, C69, C70, C71 and C76,.

LK2, LK3, and LK4 must NOT be fitted.

What do the other colours look like?

Mark

C69 was the culprit, replaced that and perfect image, may thanks!