EEVblog® Electronics Community Forum

Electronics => Repair => Topic started by: rz on November 07, 2019, 03:35:42 pm

Title: Garmin GPS 12map
Post by: rz on November 07, 2019, 03:35:42 pm

I've got a dead Garmin GPS 12map. It doesn't switch on, no display and welcome screen. I opened the case and tested the memory battery voltage, 0.5v. So, I desoldered the memory battery. After that I tested some voltages. When I push the power on button, Vcc of 80386 and AM29LV160BT are about 3.0V. Vcc of LP324 is about 25v. Frequency CLK2 of 80386 is 33MHz,  CLKOUT is 16.5MHz. RESET pin is 3v, and no high-to-low transition. That's all I have tested.

Is there some service manual or knowledge to repair this GPS? I like the GARMIN GPS 12 series very much, quality PCB and components, solid case, simple and clear display. Hope it can works again.

Thank you.

Title: Re: Garmin GPS 12map
Post by: DRM2 on April 26, 2020, 03:27:57 pm

same exact issue here.
did you ever resolve it?

Title: Re: Garmin GPS 12map
Post by: coromonadalix on April 26, 2020, 04:48:48 pm

An intel 386 sx in there ?  seems to pack some punch ??

Title: Re: Garmin GPS 12map
Post by: rz on March 31, 2023, 04:28:43 am

Quote from: coromonadalix on April 26, 2020, 04:48:48 pm

An intel 386 sx in there ?  seems to pack some punch ??

it's a intel 386ex, embedded variant of 386sx.

Title: Re: Garmin GPS 12map
Post by: eTobey on March 31, 2023, 05:50:41 am

I once fixed my HDD with reflowing it in a pan. This might work here too?