Game Gear Repair (Blinking light)

[Hippytipper]

So I just replaced all the Caps in this new GG I got. Everything is running smoothly now, except for some reason the power light keeps blinking whether plugged in via adapter or using new batteries. I swapped out the power board with another GG and yet still has the same problem.

Just curious to see if anyone else here has had a similar issue. Possibly a bad Cap?

Thanks

[Hippytipper]

Bumped:) Just found I still had this system lying around, would really like to fix the issue but have no idea what part to focus on.

Any input would be great.

[celerystalker]

Does it interrupt play or function, or is it simply the LED blinking at a steady pace as if it were dying?

[Hippytipper]

Everything appears to work just fine, but it blinks as though the batteries are dying no matter what.

I've cleaned the board, triple checked the caps, made sure there was no solder where there shouldn't be, I'm lost..
Stinks cause this system was given to me by a friend, would love to get it 100%

[celerystalker]

Could be a loose pin or wire on the molex connector that connects the power board to the main pcb... that, or possibly a diode on the circuit communicating from the power board to the LED, maybe?

[Hippytipper]

Checked the connector and looks fine to me. I had swapped the power board with another one and had the same issue, so it shouldn't be the power side of it. Most definitely on the main board. I might do a re-seat of anything that looks funky, but iduntknow

[celerystalker]

Checked the connector and looks fine to me. I had swapped the power board with another one and had the same issue, so it shouldn't be the power side of it. Most definitely on the main board. I might do a re-seat of anything that looks funky, but iduntknow

If there is a loose wire in that group in the molex connector plugging into the power board, it may be the ticket. Sometimes when removing and reseating that harness, a connection becomes weak or partially broken, as those are extremely narrow gauge wires. A gentle tug on each individual wire will make it obvious if that's the case. I run into a similar issue with arcade wire harnesses from time to time.

[Hippytipper]

Did a few different tests with it and I'm not noticing anything unordinary.
I will keep checking into it though. Thank You for SOME kind of direction, I've been bugged by this for a while, anything is helpful.

I don't remember the light blinking before I did the cap replacement, that's why I was almost sure it had something to do with that. Though I guess all the jostling around could have knocked anything loose at this point.

[celerystalker]

You probably did the cap replacement just fine, but if you aren't positive, it could be that one of the caps has too low of a rating, causing the circuit to read diminished current before the LED.

[Hippytipper]

Is it possible to know which cap (or what type of cap) is related to the LED?

[RP2A03]

I'm not sure where your trouble is, but I would try poking around pins 63, 64, and 65 on IC1 of the main circuit board. Also, if you have another Game Gear with a properly working power indicator, compare voltages at these pins. Here is a service manual which you might find useful: http://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:service_manual_-_game_gear_va1.pdf

[jb143]

Looking at the schematic that RP2A03 provided; measure the voltage anywhere it says 5V. You should get right around 5V.

Measure the voltage at pin 9 of IC1(pin 2 of SW2, pin 7 of CN1, etc...) This is your unregulated battery voltage, which should be whatever your batteries or power supply is putting out.

Unless I'm reading things wrong*, the voltage on pin 54 should be around 70% of source voltage and the voltage on 53 should be around 77% of source voltage. (2.7V and 2.04V using a 9V source). If those voltages are closer to 1.5V** then it's going to read as a low battery and flash. My initial guess is that maybe C43 is shorted? That would pull everything in that section down making it think the batteries were low.

*Bear in mind that I'm pretty rusty on this stuff.

**I'm not sure what the actual voltage is when the flashing should begin