Action 5503 small transistor TV, service info?

[dtvmcdonald]

I bought an Action ACN-5503 little 5" portable color TV (CRT) as a temporary standin for my beloved Sony KVX-370 Indextron which is out for repairs. This was off ebay for like $45, supposedly working.
It arrived very poorly packed indeed but unscathed.

It does in fact work as advertised. It will do my job.

But the vertical hold is set wrong, or maybe the AGC. Vertical hold is not a user control, making the
signal level and fine tuning rather critical. Once set, its fine. I have tried using it as a video monitor, and that works better. It probably not really AGC alone since except to very low (snowy) signals it has the problem.

But I can't find a service manual anywhere. Does anybody know about these thingies?
They are all over ebay at good prices, so must have not been rare.