heat sink gets hot

[1iwilly]

so while looking for the locations of caps to upgrade for hi-fi on my spare 2000 i notice that just idling meaning the radio on not using it the heat sink section where the 1969 is getting really hot the radio does have rf power if i disconnect one leg of from final 1969 no heat is notice just for verification i swap 1969 for another working one but same results

 

[sp5it]

What's the current flow through that transistor on standby? Measure on TP7

 

[1iwilly]

What's the current flow through that transistor on standby? Measure on TP7

tp-7 yellow wire vr-8 i have 25.9 mv doesn't matter which way i turn vr-8 i reading doesn't change

 

[sp5it]

We measure current in A, not mV
DMM in series with wire.

 

[1iwilly]

We measure current in A, not mV
DMM in series with wire.

it fluctuates Look at pic

 

[1iwilly]

c149 check good r181 is good c148 is good vr-8 pot is good tr-39 is good d49 is good brake time to dam hot here in fl even with a fan in garage

 

[Beetle]

Easy: the heat sink is full. You're going to have to empty it and install new anti-heat compound (whenever it gets invented...).

 

[1iwilly]

well made improvement turns out c152 was no good but in the process of digging now the radio is in full output power i can't lower it when turning vr-10

 

[nomadradio]

i can't lower it when turning vr-10

Shorted TR41. Probably got worked too hard while the final was pulling current on receive side. We always replace the 2SC945 TR41 that drives TR42. Cheap insurance.

73

 

[1iwilly]

Shorted TR41. Probably got worked too hard while the final was pulling current on receive side. We always replace the 2SC945 TR41 that drives TR42. Cheap insurance.

73

yeap that's what happen change to tip-41c and tr-42 a new 945 in it
working normally only issue is it was missing tr-25-26 replace them but vr-12 does nothing check the trimmer with the meter working fine diode next to it is good r131 is also intact