Hello, Second posting, have a HP2, when batteries, in charging light will blink green, or sometimes red/yellow, just powers off after a bit, if you take the batteries out , and straight power cord, will blink green, or sometime not power up , and just blink green, even with no batteries in, have tried taking memory card out and back, new batteries, still same, anyone else had problems like this.
I had a similar problem and one of the battery cells dropped its voltage under load so that my HP-1 refused to power on but still indicated full charge. Take out the batteries and test individually in a battery tester, those costs something like $5 and tests all type of batteries under load. Or test each battery in another device like a flashlite.
Did you buy it used?
If so it might have an underpowered power supply.
Try getting a universal power supply with different tips and switchable voltage settings. 9 volt 500 mamp max 210Mamp min.
Sounds like a power supply problem. Do fresh alkaline batteries work? If new batteries work on their own.
If it is still under warranty then send it in to repair.