Testing and Troubleshooting Guide

Test Setup

Powering the Logic Board

Using the 4-pin connector

Through the battery box

Powered Off Testing

Always-on +5V

There are many places to check the always-on +5V from, such as:

Pin 2 of Q16, or the heatsink attached to Q16
- There's a chance of poor connectivity between the heatsink and the body of Q16, so if you see a strange reading test from another point
The positive leg of C16
Pins 11 and 18 of the hybrid

Here is an image highlighting those points:

The +5V is typically around 5.2V, but anywhere between 5.0-5.3V should probably be fine.

Battery Level (A/D)

Powered On Testing

Powered-on +5V

+12V

-5V

Troubleshooting

Always-on +5V Troubleshooting

No voltage

Check Fuse
Low Voltage Comparator

Incorrect voltage

Check 1.2V Reference

1.2V Reference Troubleshooting

The 1.2V reference provides a reference voltage for several key parts of voltage regulation.

This is provided by a Linear Technology LT1004-1.2. The IC is marked "0412" and is located on the hybrid module.

The reference needs a small amount of current to create the reference voltage, typically around 8µA at the minimum.

Here is an image highlighting current supply path for the reference. Highlighted in yellow is the supply from the battery, through two resistors. After the second resistor the voltage should be 1.2V, highlighted in green.

If you believe the reference is not getting enough current, you can try adding a resistor (recommended size between 100kΩ and 200kΩ) to supply more current.
Be careful not to supply too much current, as the reference will have to dissipate that as heat.