Panasonic KX-FT937LA-B Service Manual page 112

KX-FT937LA-B
12.5.7.3. Broken Parts Repair Details
(D10, D11, D12, D13)
Check for a short-circuit in terminal 4. If D10, D11, D12 and D13 are short-circuits, F1 will melt (open).
In this case, replace all of the parts (D10, D11, D12, D13, F1).
(Q1)
The worst case of Q1 is a short-circuit between the Drain and Gate because damage expands to the peripheral circuit of Q1.
This is due to a very high voltage through the Gate circuit which is composed of R19, Q2, and Q21 etc.
You should change all of the parts listed as follows.
F1, Q1, R19, Q2, Q21
(D101, D104)
If D101 and D104 are broken, the oscillation circuit in the power supply cannot operate. Check it with an electric tester.
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