[JPK]

Check the usual suspects:

• Forgotten solder joint,
• Bad solder joint (reflow suspicious joints),
• Reversed components (electrolytics, tatalum's, diodes, transistors, IC's). In case of IC's, probably destroyed, better replace,
• Components in the wrong place like IC's or transistors,
• Trim all the component leads and test pins as short as possible. Nothing must touch the chassis plate.