It is currently Mon Mar 16, 2020 8:28 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 11 posts ] 
Author Message
Post subject: Fender Champion 600 died - I replaced parts but still dead
Posted: Sun Sep 22, 2019 8:10 pm
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
I've had the amp for several years, and have treated it gently, using it for bedroom playing. I loaned it to my girlfriend to use in a band practice and it was fine. When we returned a few days later for another practice she flipped the switch but got no sound at all. Speaker is fine (I used it with another amp to check), I replaced both tubes, and replaced a resistor that looked to be a bit overheated (R10) but I'm still not about to get any sound.

I can't find anything obviously damaged other than R10. The fuse is still good.

How can I locate the faulty area? Can I probe the circuit and compare measurements I take to expected values to see where the problem is?

I'd love to get this amp running again but I'm not sure what to do next. Does anybody have any suggestions?

Thanks!


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Mon Sep 23, 2019 1:56 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14045
Location: Province de Québec, Canada
We need ot know more ;

1- Do you hear some hum, hiss ? At full volume ?
Nothing : power supply issue. ( as you put 2 new good tubes and speaker is connected)

2 Do you see tubes glowing ? No ; there a heater fuse inside
3- How do you check fuse ? By eyes is not good , you need a meter

R10 is the 6V6 bias 470 ohms resistor , must be 2 watts or more. If it read close to 470 ohms resistor is good.

Tubes amp ; lethal voltage inside, amp may see a amp tech

shematic here;

https://www.thetubestore.com/lib/thetub ... ematic.pdf


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Mon Sep 23, 2019 8:06 pm
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
stratele52, thanks for the reply. Let me address those question:

There was no sound from the speaker when plugged into the fender (but worked with another amp). What type of power supply issue can these amps have? Transformer? I can say that there was some glow to the tubes (how much exactly I can't recall) and the red "on" light was lit.

As the the fuse, as you suggested I had pulled it out and tested it alone using a meter and it was passing current. That's the large one, but I just noticed that there is a small through hole fuse mounted to the board and labeled F2. I was thinking I should remove it to check for continuity even though I can't see any sign of it having popped.

R10 read some crazy value, can't recall the exact number but it was definitely way off, and i replaced it with a similarly rated resistor (or maybe I went up to 5w) - I thought I'd have the amp up and running after that, but alas, no.


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Mon Sep 23, 2019 11:23 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26415
Location: Tombstone Territory
The F2 fuse protects the heater-supply circuit -- if the pilot lamp was lit and the tubes were glowing during your attempts to diagnose the issue then there's nothing amiss with that fuse. This voltage is non-rectified AC: thus you may have a problem with the HV supply and/or the rectifier circuit.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Sep 24, 2019 1:09 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14045
Location: Province de Québec, Canada
Retroverbial wrote:
thus you may have a problem with the HV supply and/or the rectifier circuit.

Arjay


Right.

Twichmonitor,

Check voltage at R11, one side you may read close to 366 volts DC other side 360 DC
No voltage ; check voltage at TP14 ; 280 volts AC

These are lethal voltages, don't do it if you are not sure what you do

No voltage at TP14 ; check Power transformer wiring , solder and coil
Voltage at TP14 check diodes D1,2,3,4 check for broken solder on printed circuit.


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Sep 24, 2019 1:11 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14045
Location: Province de Québec, Canada
twitchmonitor wrote:


R10 read some crazy value, can't recall the exact number but it was definitely way off, and i replaced it with a similarly rated resistor (or maybe I went up to 5w) - I thought I'd have the amp up and running after that, but alas, no.


What value you put in ? In ohms ?
5 watts are ok. 5 watts resistor ( square ciment ? ) show value printed on


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Oct 01, 2019 11:27 am
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
stratele52 wrote:
twitchmonitor wrote:


R10 read some crazy value, can't recall the exact number but it was definitely way off, and i replaced it with a similarly rated resistor (or maybe I went up to 5w) - I thought I'd have the amp up and running after that, but alas, no.


What value you put in ? In ohms ?

Same value as original resistor, I think it was 470 ohms.
5 watts are ok. 5 watts resistor ( square ciment ? ) show value printed on


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Oct 01, 2019 11:30 am
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
Retroverbial wrote:
The F2 fuse protects the heater-supply circuit -- if the pilot lamp was lit and the tubes were glowing during your attempts to diagnose the issue then there's nothing amiss with that fuse. This voltage is non-rectified AC: thus you may have a problem with the HV supply and/or the rectifier circuit.

Arjay


Arjay, thanks for your help. Can you tell me what HV stands for - I'm guessing the high voltage circuit (on the AC side of the transformer)?


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Oct 01, 2019 11:31 am
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
stratele52 wrote:
Retroverbial wrote:
thus you may have a problem with the HV supply and/or the rectifier circuit.

Arjay


Right.

Twichmonitor,

Check voltage at R11, one side you may read close to 366 volts DC other side 360 DC
No voltage ; check voltage at TP14 ; 280 volts AC

These are lethal voltages, don't do it if you are not sure what you do

No voltage at TP14 ; check Power transformer wiring , solder and coil
Voltage at TP14 check diodes D1,2,3,4 check for broken solder on printed circuit.


Awesome, that's some very specific stuff I can check, I'll see what I find I let you guys know!


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Oct 01, 2019 11:36 am
Offline
Hobbyist
Hobbyist

Joined: Sat Jul 20, 2019 8:39 am
Posts: 10
stratele52 wrote:
Retroverbial wrote:
thus you may have a problem with the HV supply and/or the rectifier circuit.

Arjay


Right.

Twichmonitor,

Check voltage at R11, one side you may read close to 366 volts DC other side 360 DC
No voltage ; check voltage at TP14 ; 280 volts AC

These are lethal voltages, don't do it if you are not sure what you do

No voltage at TP14 ; check Power transformer wiring , solder and coil
Voltage at TP14 check diodes D1,2,3,4 check for broken solder on printed circuit.


Awesome, that's some very specific stuff I can check, I'll see what I find I let you guys know!


Top
Profile
Post subject: Re: Fender Champion 600 died - I replaced parts but still de
Posted: Tue Oct 01, 2019 1:16 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14045
Location: Province de Québec, Canada
Be carefull ! Only one hand in the amp ( voltmeter probe)


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: TimsAudio and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: