Hey all, got a qy70 recently that has freezing issues. Yes, i've replaced the internal coin battery with a fresh one and i've initiated a factory reset dozens of times and it still doesn't help. The freezing i'm trying to address seems like some sort of CPU hang up. Sometimes the QY70 starts up and works as normal but after a few minutes of noodling around or if I start pressing a bunch of buttons the unit will freeze and not recover. At other times the unit won't even start up and hangs up on the black QY70 screen without initializing all the way. At other times the display won't even turn on all the way, but will just flicker and not fully boot up. This leads me to believe that there is a power issue going on somewhere.
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Further, I've done all the tests suggested in the service manual and the only test that's off is the "power battery test". The manual says "this test checks the voltage of the power battery is less than 6.3 +/- .01V automatically. (measure point CPU's A/D Terminal)" (Note: i'm not sure what the CPU A/D terminal is, but i'm certain it's not referring to a DAC IC)
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When performing this test on my unit I am running at 7.3v, but i'm not sure what a power battery is.
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I saw power from the coin cell battery coming into the main CPU IC13 @ Pin 84 and it's drawing 3.3v which seems good. I started tracing down from the coin cell battery in general and how it connects to the main CPU and it's ROM and SRAM extensions and don't see any clearly visible busted capacitors. I guess i'm just asking for advice on next steps. I wouldn't mind attempting to re-cap this area, but i'm not even sure if this is the problem area!
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Again, my symptoms are that my QY70 passes every service test except the power battery, in which it runs hot. The unit turns on, all the buttons work, sometimes it boots up and functions for a bit, but always eventually freezes with enough time or if I press a bunch of buttons and overwhelm it. This leads me to believe it's a software processing flaw and it's getting hung up due to power irregularities. I'm not sure if i'm looking in the right spot though. I'll try to put together some photos for yall too
