01-08-2017, 01:22 PM
I have a GE E-71 Tombstone Rider vol 7-13 - 7-16
http://www.nostalgiaair.org/Resources/781/M0007781.htm
The chassis was covered with some tar like substance and a bit of rust to the point that I broke the 6A8 prying it off. Well I recapped it and checked the tubes all were good and I had a 6A8 to replace the broken tube also the Rectifier tube was supposed to be a 5W4 but had a 5Y3 there but my chart says this is a good sub. It had some brittle wiring and I replaced it as I went along and the Candohm Resistor had a lower value resistor spliced in R4. So I took it out and put in 5w ceramic resistors for R1-R5. Checked the resistors and replaced a few that were over 20%.
Problem is it only partially powers up. I stop bringing up the voltage I when I reach .7a and have about 80vac I don't want to hurt the transformer. C1 I get 120vdc and C2 is dead. I have powered it up with all the tubes out and the Transformer is fine as I get 350vdc to chassis off the 5W4. Now on Friday twice it actually powered up properly and I was able to put 115vac and drew about .55a. Now here is the kicker thought I had it but it won't power up! Back to square one!
Here is what I have done
1 recapped
2 replaced candohm resistor
3 replaced other resistors as needed
4 exchanged all tubes with other tubes I had.
5 Checked all the coils in the IF cans 1,2,3 (all seem to run about 6 ohms)
6 because I have a wiring diagram I have traced all the wiring for the candohm strip and the 5W4 ckt.
On page 7-15 Fig 3 C-1 & C3 shows -16v on a strap? but neither of the ecaps were insulated from the chassis so I put the neg of the new caps to chassis. Could this be where the problem is?
My apologizes for such a long post.
Eric
http://www.nostalgiaair.org/Resources/781/M0007781.htm
The chassis was covered with some tar like substance and a bit of rust to the point that I broke the 6A8 prying it off. Well I recapped it and checked the tubes all were good and I had a 6A8 to replace the broken tube also the Rectifier tube was supposed to be a 5W4 but had a 5Y3 there but my chart says this is a good sub. It had some brittle wiring and I replaced it as I went along and the Candohm Resistor had a lower value resistor spliced in R4. So I took it out and put in 5w ceramic resistors for R1-R5. Checked the resistors and replaced a few that were over 20%.
Problem is it only partially powers up. I stop bringing up the voltage I when I reach .7a and have about 80vac I don't want to hurt the transformer. C1 I get 120vdc and C2 is dead. I have powered it up with all the tubes out and the Transformer is fine as I get 350vdc to chassis off the 5W4. Now on Friday twice it actually powered up properly and I was able to put 115vac and drew about .55a. Now here is the kicker thought I had it but it won't power up! Back to square one!
Here is what I have done
1 recapped
2 replaced candohm resistor
3 replaced other resistors as needed
4 exchanged all tubes with other tubes I had.
5 Checked all the coils in the IF cans 1,2,3 (all seem to run about 6 ohms)
6 because I have a wiring diagram I have traced all the wiring for the candohm strip and the 5W4 ckt.
On page 7-15 Fig 3 C-1 & C3 shows -16v on a strap? but neither of the ecaps were insulated from the chassis so I put the neg of the new caps to chassis. Could this be where the problem is?
My apologizes for such a long post.
Eric
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