Heathkit HR-10B - Specific Problems

PROBLEM
Filaments do not light.
Filaments light, but no
sound with GAIN controls
turned fully clockwise.
Audio present -
no signals can
be heard.
Page 35
SPECIFIC PROBLEMS
CHECK
1.
Check fuse.
2. Check filament wiring.
3. Open tube filament - Check for continuity
with an ohmmeter.
4. Check power transformer wiring against
Pictorial 2.
1. Make sure the STBY-REC Switch is iwt in
STBY
position, check muting circuit.
2. Check wiring of the GAIN controls.
CAUTION: When making the following checks,
do not touch the chassis with your other hand.
Be
sure that the chassis is not connected to
an earth ground and that you touch only the
specified lug on the tube socket.
3. Turn the Receiver on and place a small
screwdriver on lug 7 of tube socket V6, then
touch your finger to the metal portion of
the screwdriver; a, low pitched hum should -
be audible.
4. Now place the screwdriver on lug 2 of tube
socket V6. Again touch your finger to the
metal portion, this time the hum should be
louder.
If no hum is present check the components
of tube V6 and the wiring to the speaker
jack,
CAUTION: When making the following tests,
do not touch the chassis with your other hand.
1. Place a small screwdriver on lug 2 of tube
socket V 4 and with your finger, touch the
metal portion of the screwdriver. A low
pitched hum should be heard.
2.
3.
4.
If no hum is present, check the components
around tube soc~et V4.
Similarly, make the screwdriver test on lug
1 of tube
socket V3. The hum should be
louder.
Similarly, make the screwdriver test on lug
2 of tube socket V2. The hum should be
louder.
Similarly, repeat the screwdriver test on
lug
1 of tube socket Vl. The hum should
be louder.
If no hum is present or if the hum level
does not increase, check the components on
the circuit around the tube sockets.