Noise, Heat, and Sparks: Oh My!

MrPotatoSalad · 11569

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Offline MrPotatoSalad

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Reply #30 on: September 04, 2014, 06:25:31 AM
With T1/5 switch:
T1:132
T2:170
T4:170
T5:96

If I exchange the 12AU7, do I just pay for shipping and do I have to send my tube in before I get the new tube?



Offline Paul Birkeland

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Reply #31 on: September 04, 2014, 07:50:42 AM
Yeah, just pop it in the mail, first class post is inexpensive and should get here quickly. We will take care of the outbound postage.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline MrPotatoSalad

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Reply #32 on: September 05, 2014, 11:48:05 AM
Put in a new transistor on the lower large PC board and still all the LEDs are out except the two lower LEDs on the large PC board glow bright and the LED on A8 is lit.



Offline MrPotatoSalad

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Reply #33 on: September 05, 2014, 11:50:54 AM
I suppose I should say I put in the SB again if that wasn't clear.

Should I try replacing the other TIP50, or is there something else wrong?

Can I keep the small PC boards in and just replace the large PC board with the two 10W 3K resistors?
« Last Edit: September 05, 2014, 01:11:34 PM by MrPotatoSalad »



Offline MrPotatoSalad

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Reply #34 on: September 05, 2014, 03:09:36 PM
Removed the large board and replaced with the 3K resistors. All LEDs went on and I still have same bad voltages as before. However, now the sound in the left ear piece has cut out so it is very quiet now. No problems with distortion, just low volume in left ear.

All resistances OK.
« Last Edit: September 05, 2014, 03:15:13 PM by MrPotatoSalad »



Offline Paul Birkeland

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Reply #35 on: September 05, 2014, 07:20:34 PM
I would wait until you can exchange the 12AU7's before doing much more.

Also, you really ought to replace both the TIP50 and 2N2222 in the offending channel. 

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #36 on: September 06, 2014, 05:22:55 AM
I agree. LEDS that won't light are often fine but the corresponding 2n2222 is blown.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline MrPotatoSalad

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Reply #37 on: September 06, 2014, 06:41:38 AM
The LEDs are not dead. They all light up slightly when I do a resistence check on them. They just will not light up when they are in the Crack.
I'll just get new transistors for all the boards.



Offline Doc B.

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Reply #38 on: September 06, 2014, 01:15:51 PM
I'll suggest only replacing the transistor at the point where you are seeing the problem. They are a hassle to change out and if the rest are working OK it would probably the cleanest and least risky to just replace the bad one.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline MrPotatoSalad

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Reply #39 on: September 06, 2014, 03:13:42 PM
I'll suggest only replacing the transistor at the point where you are seeing the problem. They are a hassle to change out and if the rest are working OK it would probably the cleanest and least risky to just replace the bad one.
Thanks, I'll keep the others as replacements just in case. Had to order $10 anyways to avoid $5 charge.



Offline MrPotatoSalad

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Reply #40 on: September 10, 2014, 11:20:54 AM
Got an RCA Cleartop and voltages are good and noise is gone. Volume control is improved as well. Simply beautiful. I'll send my weak tube in for replacement tomorrow.

Thanks a lot PB.  ;D
« Last Edit: September 10, 2014, 11:26:31 AM by MrPotatoSalad »



Offline Natural Sound

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Reply #41 on: September 10, 2014, 11:30:21 AM
Got an RCA Cleartop and voltages are good and noise is gone. Volume control is improved as well. Simply beautiful. I'll send my weak tube in for replacement tomorrow.

Thanks a lot PB.  ;D
Did you replace the transistor AND the tube OR just the tube?



Offline MrPotatoSalad

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Reply #42 on: September 10, 2014, 11:38:13 AM
Did you replace the transistor AND the tube OR just the tube?
Just the tube for now. The Speedball is out until tomorrow when I get my transistors.



Offline MrPotatoSalad

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Reply #43 on: September 11, 2014, 10:46:43 AM
Switched out the lower TIP50 and 2N2222A transistors and I am still getting bright glowing LEDs on lower main board as well as the LED at A8 lighting up but normally.

The spark that caused this to happen originally was at T7, so would that affect the lower, upper, or whole main board. Should I try replacing upper transistors?







« Last Edit: September 11, 2014, 10:49:02 AM by MrPotatoSalad »



Offline Paul Birkeland

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Reply #44 on: September 11, 2014, 10:57:14 AM
What are your current voltages?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man