This manual is accurate and of high quality. It is only volume 2 of the service manual. This is schematic, parts lists, and exploded mechanical drawings. The theory of operation and the diss-assembly instructions are in volume 1. The unit can be tricky to dis-assemble portions of so the volume 1 manual can be important. The product description of the manual is accurate but it does not say anything about volume 1 and the image of the front page does clearly say Volume 2.
It has all the information you will need to fix it. The main circuit diagram is only A4 but being a PDF, you can print it to any size - I did it on two sheets of A3 and it didnt lose any detail - just made it readable when pinned up above the bench. I've found the fault, just need to buy some obscure bits to get it going again!
I cant fault the process, I paid for the manual in the morning and it was ready to download by lunch time.
Text excerpt from page 56 (click to view)
GX15
3. No voice is heard from the earpiece.
Phone (Handset) Do keypad tones and melodies sound?
YES
CONFIDENTIAL
NO
Go to the section �Earpiece (for loud speaker) does not work�. (see page 2-50)
Is 0.5 V or more applied to R101 (IC103 pin 9 side)?
NO
YES
IC103 is defective.
Is 0.5 V or more applied to JK101 pin 5?
NO
YES
Parts between socket JK101 pin 5 and IC103 pin 9 are defective.
Is 0.5 V or more applied to JK101 pin 3?
NO
YES
Socket JK101 is defective.
Is 0.5 V or more applied to TP120?
NO
YES
Parts between socket JK101 pin 3 and TP120 are defective.
Is 2.4 - 2.6 V applied to TP176?
NO
YES
R122 is defective.
Is 2.4 - 2.6 V applied to R115 (IC103 pin 76 side)?
NO
YES
R115 is defective. (Hands free kit mode is set.)
IC103 is defective. Hands free kit (Headset) Replace the hands free kit. Is sound produced?
NO
YES
The hands free kit is defective.
Is signal sent to JK101 pin 4?
NO
YES
Socket JK101 is defective, or the hands free kit is in a poor contact with the socket plug.
Is signal sent to TP121?
NO
YES
Parts between socket JK101 pin 4 and TP121 are defective.
Is signal sent to R124 (IC103 pin 60 side)?
NO
YES
Parts between IC103 pin 60 and TP120 are defective.
Disconnect the hands free kit. Is voice heard in phone mode?
YES
