Yet another Nanao MS9 help thread. Stuck in 24khz mode

[HolySNES]

Ok, I'm at a loss now so need some expert guidance.
I have a Nanao MS9-29S chassis I'm trying to get going in a new Astro. It's from a Daytona cab so it's been set to 24khz mode via the jumper. The chassis is identical to the chassis that was previously in the Astro (both MS9-29S). So I've popped this one in, set the jumper to 15khz and it's not syncing. It's displaying the image but yeah, it's like the 15khz jumper does absolutely nothing. It works in 24khz with a medium res game but not in 15khz. It's recently had a new cap kit installed (the standard electrolytic caps) so unless it's another cap not in your standard cap kit then i'm stuck. Could it be a resistor or diode causing the issue? A transistor?
Any help on where to start would greatly be appreciated.
I also have 2 more MS9-29S chassis. One is fully working and the other is in HV protection mode, so I can savage components from them to test but I wouldn't know what parts to start with.

Game playing is X-Men vs Street Fighter

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[yosai]

Just to be clear your moving the connector at 20 (24k) to 19 (15k) ?

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[HolySNES]

Just to be clear your moving the connector at 20 (24k) to 19 (15k) ?

Yes that's the connector I'm switching

[HolySNES]

Switching the jumper to 24khz mode shows a little more of the image but it's a little more unstable (more flickering?)

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[grantspain]

do the h.hold pots do anything?

[HolySNES]

do the h.hold pots do anything?

Oh boy I'm so embarrassed. First thing I checked when I installed it was the 15khz horizontal hold. I couldn't see whilst I was adjusting so I got my son to stand in front and tell me if anything changed. "Nothings changing" was his reply. "Are you sure? What about now?" "No it's just getting more fuzzy" ruled that out and didn't go back to it until you mentioned it. Thought I'd grab the DMM and test whether the pot was still good. A little turn and yup, sure enough it was the pot. Serves me right for using a kid as a T.A.
Sorry for wasting a thread and thanks heaps for the replies
There's still the matter of the monitor in protection mode... But I'll get to that another day

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[FcoBenitez]

Kids, what do they know?