Rockbox Technical Forums

Third Party => Repairing and Upgrading Rockbox Capable Players => Topic started by: Moogle on October 20, 2018, 02:32:08 PM

Title: Sansa Fuze V1 Battery Replacement
Post by: Moogle on October 20, 2018, 02:32:08 PM
Hello. I wonder if any of you have successfully replaced a Fuze V1 Battery?

I have managed to do it with an aftermarket battery off ebay. It will power the Fuze up and it does work, but it won't charge.

I suspect it might be something to do with the Thermistor. The resistance at room temp,  measured with the battery disconnected from the Fuze is 100 kOhm approx (between the battery - vehicle terminal and the Thermistor wire).

 I unfortunately discarded the old battery and didn't make any measurements on it.

Any ideas?
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: saratoga on October 20, 2018, 08:01:18 PM
Does the debug menu show the battery temp on the v1? I don't have one in front of me to check.
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Moogle on October 21, 2018, 06:44:48 AM
Good thinking Saratoga. Unfortunately the new battery is completely drained now, so the Fuze won't switch on, even with the charger connected.

Guess I'll need to do some more surgery before I can report back.
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Moogle on October 21, 2018, 04:00:37 PM
I manage to coax it back to life, but unfortunately there doesn't seem to be a battery temperature reading.

I guess this would be within the View Battery data, but this seems to relate only to Voltage history.
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: saratoga on October 21, 2018, 04:16:16 PM
Looks like its the ADC channel labeled "BatTemp". 

Edit:  Datasheet suggests that 100k is the default thermistor impedance, so that is probably correct unless they changed it.
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Moogle on October 21, 2018, 05:04:46 PM
It's denoted in mV,  and is fluctuating between 0 to 5, with the Fuze idling. 
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Moogle on October 27, 2018, 03:22:14 PM
Reporting back: the new battery was faulty even though the Thermistor reading seemed correct. Got a replacement and it charges fine

BTW, I've now stripped and rebuilt my Fuze 3 times, so, as the few guides that are available online leave something to be desired IMO, please feel free to drop me a line to stewartb942 at googlemail  dot com if you'd like some advice.
Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Jerrymc777 on January 26, 2019, 12:01:03 PM
I just picked up a Fuzev1 (Not +Plus) on ebay and it appears the batt. is dead.
It does power ON as long as the cable is connected to a power source.
Immediately upon disconnect, it powers OFF.

I am only familiar with the Sansa c200 and e200 series, and have recently replaced the battery in the e250.

I was able to update the Sansa newest 01.02.31 FW while it was plugged into the PC, but cannot load RB because once I get to Settings to switch the USB mode, (the only way I can get into the Settings menu is by plugging it into an AC USB connector, Not PC) then plugging it into the PC, it's already OFF.

It plays awesome on my stereo system and reads all of my music on the $5 32GB card, while plugged into a power source of course.

I'm assuming the main battery holds the RTC settings...?
Because the time ALWAYS reverts back to 12:00, even though I've updated it to current.
Or is there some other internal CMOS batt I'm unaware of.. ?

Any help is tremendously appreciated!  ;D



Title: Re: Sansa Fuze V1 Battery Replacement
Post by: Moogle on February 20, 2019, 01:39:52 PM
It sounds like you have both the AC charger and the USB cable.

You could modify them to make a hybrid cable to allow the Fuze to be connected to your PC while connected to the AC charger. (note, this is theoretical as I haven't tried it, but I'm pretty certain it should work.

To do this you'd need to cut the Fuze connector off the AC Charger lead. Then you'll need to identify the positive and zero voltage wires. (leave a few cm of cable attached to the Fuze connector which will make a later repair of the cable easier.)

Then you'll need to carefully cut into the outer sheath of the USB cable to expose the wires inside.

First, identify the positive voltage wire. Cut it and connect the end that goes to the Fuze to the positive wire of the charger

Then identify the negative wire, cut it, and then connect both ends to the charger 0 volt line.

So, the Fuze will be getting its power from the wall, but it's data lines will be connected to the PC, which should allow you to do the manipulation you need.

When you're finished you can repair your cables with a soldering iron and some heat shrink sleeving.

Good luck!