still got vibrate when turn on but the the screen is black out......is there even any start up sound?

i haven't experience this before...but anyway here's some checklist for you...
posibility 1 : hardware issuefirstly, take out the battery and check the 3 pin connector on your TP [ the gold color pin which physically touch the battery ] - check is any of the pin dented / broken especially the middle pin. if dented, try straighten it back, reinsert battery and turn it on again....if all the 3 pin are in good conditions, proceed to the next step:
possibility 2 : bad radio rom / bad flash follow bro pcboy instruction, enter into bootloader mode....if you can manage to into bootloader means you had a bad flash [ very highly the radio culprit ] previously...don't take any chances anymore,immediately flash back to stock spl and rom.
if still cannot turn on, the only
possibility is : dead screen / fried board...send back to SIS and pretend that you're still noob using pda and if they voice out about warranty void because of custom spl/rom.....simply tell them it's not your fault, tell them it's your phone dealer whom 'install' the cooked rom for you without even noticing it...
cheers up bro!
Now thinking back most probably its the moisture in my car that caused my TP to have the problem. I've parked my car outside my kampung and its nearby forest so its quite cold during the night. I left my TP inside my car for one full day under direct hot sun and now its ALIVE !
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Anyway thanks to everyone which gave all the necessary advices and steps to revive me TP !