Trio TS 820s

Jeg er den lykkelige ejer af denne ældre HF radio. Den har fået det problem at kort tid efter den bliver, tændt bliver den total tavs. Sender virker.
Hvis den så slukkes og tændes igen, virker den igen i få sekunder og bliver da helt tavs igen. Nogen forslag til fejlfinding.
73’ Anders OZ0AP

Svar til #1:

A Trio/Kenwood TS-820S receiver going dead shortly after power-on is a common issue typically caused by thermal expansion affecting weak solder joints, dirty relay contacts, or failing power supply components as the unit warms up
.
Based on user experiences with this vintage transceiver, here are the most likely causes and solutions:
1. Dirty or Defective Antenna Relay
The TR (transmit/receive) relay contacts can become oxidized or covered in carbon, causing the receiver to cut out, particularly after the radio heats up.

Symptom: Receiver works initially, then goes quiet. Tapping the relay may bring it back.
Solution: Locate the relays (center of the radio, often under plastic covers), gently remove the covers, and clean the contacts with burnishing tool or paper soaked in contact cleaner.

2. Molex Connector and Solder Joint Failures
The TS-820S uses Molex connectors that are notorious for developing cracked solder joints ("cold solder joints") on the circuit boards. As the radio heats up, the metal expands, breaking the connection.

Symptom: Wiggling boards or connectors (especially on the 'Fixed' or AF-AVR board) restores audio.
Solution: Inspect the solder connections on the molex connectors, particularly on the IF-A board and the VFO unit, and reflow any suspect joints.

3. Power Supply Voltage Issues
If the receiver stops working the 9V or -6V supply lines may be failing when hot.