HP TouchSmart AIO's chassis is stuck at stand down and lowest position. How to fix it?

The AIO spec.:
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HP TouchSmart 610XT (2MD1190F3S)
The chassis spec:
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Chassis number 640287-ZH1
CT number LBVAR01MHZZ0DW.
(FBZN9025010 REV:2C)

Solution:
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By using flat screw to push the side of the chassis to release/unlock the stand locked potion.