sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #60 on: February 03, 2019, 06:26:54 AM »
Ok so I reflowed all power tubes joints and this time I switched on the amp without limiter and took reading of anode at one power tube. This is the result:

https://youtu.be/6OJpr0qItp0

Any ideas on what's wrong with it and how to fix it please?
Thanks a lot

Cheers
Sono
Why sleep when you can mix?
M.P.Stavrou


abbey road d enfer

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #61 on: February 03, 2019, 07:31:32 AM »
Ok so I reflowed all power tubes joints and this time I switched on the amp without limiter and took reading of anode at one power tube. This is the result:

https://youtu.be/6OJpr0qItp0

Any ideas on what's wrong with it and how to fix it please?
Thanks a lot

Cheers
Sono
Could be a tube arcing. What happens when you take all other tubes, leaving just the power tubes?
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Mylithra

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #62 on: February 03, 2019, 07:56:01 AM »
Starting at V1, start pulling preamp tubes till the noise goes away. Concentrate you search around the tube that made the noise go away.
You have good bias supply at the grid of the power tubes? If you have noise in the bias supply, you're injecting it right to the input of the power tubes.

sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #63 on: February 03, 2019, 08:06:38 AM »
Could be a tube arcing. What happens when you take all other tubes, leaving just the power tubes?

Ok, I'll do that this afternoon Abbey ;)

Starting at V1, start pulling preamp tubes till the noise goes away.
You mean taking out V1, switching the amp on, check noise, switch off, pull out V2, switch on, check noise and so on, right?

You have good bias supply at the grid of the power tubes?
No idea. Voltage seems ok. I guess I'll have to use the scope at the bias check point to know if there's noise in that signal, correct?

Thanks a lot to both for your guidance! 8)
Cheers
Sono
Why sleep when you can mix?
M.P.Stavrou

Mylithra

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #64 on: February 03, 2019, 09:22:28 AM »
>You mean taking out V1, switching the amp on, check noise, switch off, pull out V2, switch on, check noise and so on, right?

Yes, though I know some experienced guys here in Texas that will turn the amp on. Once it warms up, will start pulling pre tubes up to and including the phase inverter to find noises but powering it off to pull the tube is much safer.
I personally think it would suck to have a tube break in your hand. It would suck even more if it was hot and electrified.

>I'll have to use the scope at the bias check point to know if there's noise in that signal, correct?
There are other ways but that's the easiest and safest.

sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #65 on: February 03, 2019, 11:50:03 AM »
Ok, so I took the preamp tubes out and the noise seems to have gone.
I pulled V1, same noise, pulled V2, same thing, pulled V3 and noise is gone.
Do you think it's the tube? It's supposed to be new but I can try with a new one if you want.
Going to check bias noise now :)

Cheers
Sono
Why sleep when you can mix?
M.P.Stavrou

sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #66 on: February 03, 2019, 11:56:42 AM »
Ok so this is quite amazing....I swapped V1 with V3 and popped in all the tubes back again: no noise....
So I plugged in a guitar and it sounds cool!!!
WTF????
Why sleep when you can mix?
M.P.Stavrou

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #67 on: February 03, 2019, 01:41:49 PM »
Ive worked on a fair few Deluxes and modern Fender amps , A very common fault is damage to either preamp  valve sockets where the pins go in or they lift from the pcb where there soldered , almost always when this happened the user tried to change tubes themselves , either missaligned the pins or used to much force and damaged the board in the process , it can be hard to spot too . As a matter of course now I reflow all the tube pin connections on them . If you have a pin thats got a partial intermittant connection ,you  could well have arching ,in that case the pin wont really take soldering well until you clean away all the oxidised solder and carbon first . With old bakelite sockets you can often scrape or sand away any carbon deposits ,ceramic sockets that are glazed clean up fine too ,but some un glazed ceramic types hold onto the dirt as the surface is rough .
Carefully inspect all your tube sockets ,wash away any signs of arc with an old tooth brush and isopropyl , if you do happen to find a pin with  bad solder ,first use a solder sucker or wick to remove the crud ,then scrape the pin especially around the soldered area as it will have hard crust on the outside due to the arc .Add a little more and better quality solder when you reflow it , should last for years . I have seen it happen as well like in your case that swapping out the tube appears to fix everything ,ocassionally due to a bent pin on the tube it just about makes contact or just about doesnt ,swapping in a new tube with nice straight pins and things can seem fine again for a while .

Oh yes one more thing , If you are using JJ tubes , I have seen some bad faults in them brand new out of the box , they seem to be popular in europe  ,but most of the ones I ever saw were very microphonic if not electrically noisey as well .I know quite a few who were duped into paying extra for E83cc's  and E34L supposedly 'special quality ' , they were as bad as the worst Chinese tubes I saw over the years for reliabillity .
« Last Edit: February 03, 2019, 01:54:15 PM by Tubetec »

Mylithra

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #68 on: February 03, 2019, 01:45:21 PM »
Ive worked on a fair few Deluxes and modern Fender amps , A very common fault is damage to either preamp  valve sockets where the pins go in or they lift from the pcb where there soldered , almost always when this happened the user tried to change tubes themselves , either missaligned the pins or used to much force and damaged the board in the process , it can be hard to spot too . As a matter of course now I reflow all the tube pin connections on them . If you have a pin thats got a partial intermittant connection ,you  could well have arching ,in that case the pin wont really take soldering well until you clean away all the oxidised solder and carbon first . With old bakelite sockets you can often scrape or sand away any carbon deposits ,ceramic sockets that are glazed clean up fine too ,but some un glazed ceramic types hold onto the dirt as the surface is rough .
Carefully inspect all your tube sockets ,wash away any signs of arc with an old tooth brush and isopropyl , if you do happen to find a pin with  bad solder ,first use a solder sucker or wick to remove the crud ,then scrape the pin especially around the soldered area as it will have hard crust on the outside due to the arc .Add a little more and better quality solder when you reflow it , should last for years . I have seen it happen as well like in your case that swapping out the tube appears to fix everything ,ocassionally due to a bent pin on the tube it just about makes contact or just about doesnt ,swapping in a new tube with nice straight pins and things can seem fine again for a while .

This!!
Entirely possible you have a bad pre tube as well. If you have some known good pre tubes, I'd use those until you can confirm or deny that the existing pre tubes have issues.

sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #69 on: February 07, 2019, 05:16:00 AM »
I think you're right. When I lightly chopstick v3 (from right to left, the closest to the power tubes)I get all kind of noises. I think there's a problem between socket and Board...
Why sleep when you can mix?
M.P.Stavrou


sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #70 on: February 07, 2019, 05:43:09 AM »
Ok so I found that one of V1 socket pins on the board was broken. No more copper :(
I tried the same fix as with the resistor:





Unfortunately nothing changed.....I checked all the other pins and no go.
I think I'm gonna tell my friend that he treats his amp like sh*t!!  ;D
Why sleep when you can mix?
M.P.Stavrou

sonolink

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #71 on: February 07, 2019, 05:46:45 AM »
Btw the resistor fix ended up like so:







Thanks a lot for all your help and guidance :)
Cheers
Sono
Why sleep when you can mix?
M.P.Stavrou

Mylithra

Re: Help finding correct component with Fender Hot Rod Deluxe
« Reply #72 on: February 07, 2019, 07:17:27 AM »
yeah.. those Fender board cant take a lot. Ive lifted traced on those far easier than anything other circuit board I've ever worked on. Low heat with those.


 

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