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Old 8th May 2009, 8:40 pm   #127
stonehopper
Tetrode
 
Join Date: Apr 2009
Location: St Albans
Posts: 50
Default Re: Roberts RT7 - problem

I have gone back and rechecked the soldering. It seemed OK. So with power on I began to gently tap the TR's and C's on top with a plastic tool. Then went under the board to do the same on the joints. Still no squeaks or pops, so went to check the Voltage readings on the TR6 & TR7 again. Felt around and all cool to touch.

TR7 E 0.08V; B 0.23V; C 9.24V
TR6 E 0.18V; B 2.78V - at which point I stopped, because that read zero before. I then went back to check TR7's Base again, as I thought I might have got the decimal point in the wrong place. It read 4.6V and rising. I then put my finger on the TR6 & TR7, and now have a circular burn for it! Immediately unclipped the battery and left it alone. battery now at 8.73V. T2 was definitely warm to touch now. (Finger OK, not stinging, just a shiny circle!)

Will leave it for tonight.

Derek
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