Quarterhorse Battery and Resistor Check

This note applies to some Quarterhorse hardware version 1.3 (fw ver 1.6) units.

The battery and circuit on the QH v1.3 is designed to last 5+ years before needing replacement. However, a number of QH units were shipped with the incorrect resistor in location R4. This can lead to premature battery drain (less than a year). These units were primarily shipped out during 4Q2012 as a result of undetected assembly error (our bad, sorry!).

If the BR2330A battery on the QH has become low (<2.0v) and/or the QH is losing its memory when the USB is disconnected, it might have been affected by this incorrect resistor placement. A voltage of 2.5v or better should be OK.

To check your QH, measure the resistance (ohms) across R3 (reference) and R4 (placement in question). The correct resistors will give readings of  R3=1.0k and R4=10k (within 5% or so). If R4 instead measures 1.0k, then the unit is affected and R4 needs to be changed to the correct value of 10k. R3 should be fine at 1k on all units.

The solution to this issue is to perform the following:

1) Measure the voltage of the battery (leads are accessible at the bottom of the QH). Record value (good = 2.5v or better, bad = 2.0v or less typically <1v by the time there is a problem).

qh_bat

 

 

2) Measure the resistances across R3 and R4. The ohm readings should be R3=1k, R4=10k.

qh_res

 

3) If the battery voltage is low from step (1) and/or the R4 reading is 1k instead of the correct 10k, then send the unit to us via the RMA option and we will update it for you with a fresh battery and the correct R4 resistor of 10k.

 

Once the correct resistor is in place, a fresh BR2330A battery should last 5+ years.

If you have any questions or believe your QH is affected, please go forward with the RMA process and we will take care of your unit. If you really want to go ahead and perform the update yourself (0402 SMD resistor and TH battery solder work), we can also send you the parts at no charge, just indicate that you want them shipped ahead in the comments section of your RMA submission.

The corrective service is free, and turnaround time is typically only 3-4 days. If you are indeed affected, we will happily work to get you up and running as quickly as possible.

We apologize for any inconvenience.

Hope this helps,

Craig Moates