Help my BDRI

[Cramer1]

My Blues Deluxe Reissue has severely low output when running through inputs 1 or 2 (1 on a scale of 1-10). If I run into the “Power amp in” input, I get full volume. If I swap V1 and V2 I get no sound, swapping V1 and V3 gets me sound but not even a 1 on the scale. I don’t hear any microphonics, they all glow. They appear to be the original groove tubes and the PCB is dated 2004. And tips or tricks? TIA.

[sluckey]

Connect preamp output jack to another amp. Any sound?

Check voltages on V1 and V2. Check voltages on U1. Trace signal from input jacks to input to TP22 using a scope or listening amp.

[Cramer1]

I haven’t tried preamp to a different amp, but I did jumper preamp to power amp in. I checked some voltages last night around V1 and V2 based on test points on the fender schematic and they were severely off, showing V readings when it should have been mV.

[sluckey]

I checked some voltages last night around V1 and V2 based on test points on the fender schematic and they were severely off, showing V readings when it should have been mV.

Voltages shown in the ovals are SIGNAL voltages and are only valid when you inject a 4mVAC test signal into J1. You need a scope to trace the test signal through the amp. The voltages I'm interested in are DC volts on the tube pins.

[shooter]

guessing this is the animal you have?

https://el34world.com/charts/Schematics/files/Fender/Fender_blues_deluxe_deville_reissue_vintage_.pdf

[d95err]

If there’s a significant difference when swapping the preamp tubes around, one of them is probably bad. Swap each one with a new (or known good) tube and see if it fixes the problem.

[sluckey]

guessing this is the animal you have?

https://el34world.com/charts/Schematics/files/Fender/Fender_blues_deluxe_deville_reissue_vintage_.pdf

I never heard the word "deville". I'm looking at this schematic...

     https://el34world.com/charts/Schematics/files/Fender/Fender_blues_deluxe.pdf

[pompeiisneaks]

Knowing the exact one is important, but the only difference I recalled from the blues deluxe vs the  blues deville was 2x6L6 vs 4x6L6 and 1 vs 2 speakers no?  I think the rest is pretty  much identical?

The problem is that there are no like 3 or 4 generations of the BD, so just saying RI is a bit confusing for sure.  Which generation is it?

~Phil

[shooter]

"deville".

I was looking for the word "re-issue" 

the PCB version I worked on was a C-made mess!
sloppy solder, connectors that an amateur could flip n "make" fit.  I got the one I looked at working - with a 5 minute warranty n NO call-back    

[sluckey]

I think "Blues Deluxe Reissue" is a red herring! 

[shooter]

I like anchovies, herrings are for bait 

[DummyLoad]

check tubes as stated, also, check the +/-16V power supply rails - that amp uses Zener regulation for those two power supplies - lots of IC chips in that amp in the signal path that use +/-16V.

--pete

[Cramer1]

guessing this is the animal you have?

https://el34world.com/charts/Schematics/files/Fender/Fender_blues_deluxe_deville_reissue_vintage_.pdf

Yes that’s what I have. It seems at this point that tube swapping may be my best course of action?

I know these amps have gremlins, but it was literally given to me because the previous owner didn’t want to mess with it, surely I can fix it for less than it’s worth lol.

[Cramer1]

I checked some voltages last night around V1 and V2 based on test points on the fender schematic and they were severely off, showing V readings when it should have been mV.

Voltages shown in the ovals are SIGNAL voltages and are only valid when you inject a 4mVAC test signal into J1. You need a scope to trace the test signal through the amp. The voltages I'm interested in are DC volts on the tube pins.

Can you give me an example?

[Cramer1]

check tubes as stated, also, check the +/-16V power supply rails - that amp uses Zener regulation for those two power supplies - lots of IC chips in that amp in the signal path that use +/-16V.

--pete

I did see last night that the top side of R78 is discolored, but I could not find it on the schematic to reference what the voltage should read across it. I’ll try and upload a picture.

[DummyLoad]

R85 & R86 in the schematic. if you do not see either +16V or -16V rail then the op-amps would not be working.

--pete

[shooter]

surely I can fix it for less than it’s worth lol.

worth is in the eye of the beholder 

like Pete said, the low volts, then the tube volts will go ALOT farther than swapping tubes.
WITH NO POWER;
A complete visual of BOTH sides of the board, use a chop stick and thump on parts, especially bigger Ecaps, you're looking for "loose teeth".  look for "browning" around and inside connectors and check the for looseness

and;

because the previous owner didn’t want to mess with it

your friend is wise 

[Cramer1]

surely I can fix it for less than it’s worth lol.

worth is in the eye of the beholder 

like Pete said, the low volts, then the tube volts will go ALOT farther than swapping tubes.
WITH NO POWER;
A complete visual of BOTH sides of the board, use a chop stick and thump on parts, especially bigger Ecaps, you're looking for "loose teeth".  look for "browning" around and inside connectors and check the for looseness

and;

because the previous owner didn’t want to mess with it

your friend is wise 

Don’t sugar coat it lol

[Cramer1]

R85 & R86 in the schematic. if you do not see either +16V or -16V rail then the op-amps would not be working.

--pete

Op-amps?

[DummyLoad]

https://www.google.com/search?q=op+amps.&rlz=1C1SQJL_enUS887US887&oq=op+amps.+&aqs=chrome..69i57.1735j0j8&sourceid=chrome&ie=UTF-8

forget how to google stuff?     

take with levity please.

see attached.


--pete

[Cramer1]

Hey man I really appreciate it.

Also what did you mean by +16V or -16V rail? (I did try and google that one lol)

My background is in industrial I/E but when I start digging into actual electronics it’s a different animal. The learning is fun though.

[shooter]

I did try and google that

try "basic series and parallel electronic circuit understanding"

Op amps typically use a dual PS hence + and - 16vdc.  the schematic shows where it should be, is it?

[Cramer1]

https://www.google.com/search?q=op+amps.&rlz=1C1SQJL_enUS887US887&oq=op+amps.+&aqs=chrome..69i57.1735j0j8&sourceid=chrome&ie=UTF-8

forget how to google stuff?     

take with levity please.

see attached.


--pete

Is that the schematic for an original BD or a reissue?

Also, I see mentions of the “big white rectangle” resistors being R85/R86. But on my drawing they are labeled R78/R79 unless I am missing something. Again, thanks for all the help.

[shooter]

do you have 2 power tubes OR 4?  there are 2 different schematics, both "close enough"

here's a visual, you have one of these, the RED circles APPLY to both, the names are changed to protect jobs, not confuse techs.

[Cramer1]

do you have 2 power tubes OR 4?  there are 2 different schematics, both "close enough"

here's a visual, you have one of these, the RED circles APPLY to both, the names are changed to protect jobs, not confuse techs.

2 power tubes. Thanks man! That gives me something to chase down after work.

[shooter]

while you're at work wasting the bosses money :) download the pdf I linked in reply 4
READ pages 4 n 5 til you can recite them in your sleep, then print-out the schematic and study it til ALL you see is symbols that make sense.

If none of that seems fun, trade it for a something fun on crags list 

[Cramer1]

while you're at work wasting the bosses money :) download the pdf I linked in reply 4
READ pages 4 n 5 til you can recite them in your sleep, then print-out the schematic and study it til ALL you see is symbols that make sense.

If none of that seems fun, trade it for a something fun on crags list 

:laugh:Will do!

[Cramer1]

so I finally pulled the board and the joints at R78/R79 look crappy as. R79 measures 540 ohms which is out of tolerance for a 470 rated resistor. My question is could that level of deviance drop signal out?

It looks like a previous repair to me, but who knows.

I am considering pulling the board completely and having it retrofitted with real wiring.

[Cramer1]

Pic

[sluckey]

so I finally pulled the board and the joints at R78/R79 look crappy as. R79 measures 540 ohms which is out of tolerance for a 470 rated resistor. My question is could that level of deviance drop signal out?

no

[Cramer1]

do you have 2 power tubes OR 4?  there are 2 different schematics, both "close enough"

here's a visual, you have one of these, the RED circles APPLY to both, the names are changed to protect jobs, not confuse techs.

I replaced R78/79 and reflowed any questionable looking joints on the back of the board the reinstalled the board.

TP readings are as follows:
TP37 445V
TP38 444V
TP39 413.8V
TP40 385.4V
TP45 +16.63V
TP46 -16.5V

Same symptoms as before; Low
Output through the preamp, full volume using the “power amp in” input.

Ideas?

Thanks everyone for the help.

[shooter]

Same symptoms as before; LowOutput through the preamp, full volume using the “power amp in” input.

so pre OUT to a good amp - low output?
power amp IN (from a good pre-amp) - low output?


 

[Cramer1]

Same symptoms as before; LowOutput through the preamp, full volume using the “power amp in” input.

if I plug directly into the power amp in input, I get volume from my guitar, I have not run from another amp into it. I have not run preamp out to another amp, but I have jumpered between preamp out and power amp in and still get low output.




so pre OUT to a good amp - low output?
power amp IN (from a good pre-amp) - low output?

[tubeswell]

The way those 5w cement resistors are situated and mounted on the PCB are a known design problem and a common cause of problems in the Blues And Hotrod Deluxes (including random channel switching). It causes heat problems that ultimately cook the board traces and the nearby components for the +/- 16V dual rail power supply (16v Zeners and the e-caps). It can also affect the op-amps that run on the 16v PS. You may need to replace everything there (but even if you do, the board may be cooked beyond repair, in which case the only worthwhile course of action is a rebuild with a different type of board).
The IC filter caps are also a common cause of problems, so inspect them carefully for bulges and leaks.

[Cramer1]

The way those 5w cement resistors are situated and mounted on the PCB are a known design problem and a common cause of problems in the Blues And Hotrod Deluxes (including random channel switching). It causes heat problems that ultimately cook the board traces and the nearby components for the +/- 16V dual rail power supply (16v Zeners and the e-caps). It can also affect the op-amps that run on the 16v PS. You may need to replace everything there (but even if you do, the board may be cooked beyond repair, in which case the only worthwhile course of action is a rebuild with a different type of board).
The IC filter caps are also a common cause of problems, so inspect them carefully for bulges and leaks.

I replaced the resistors and reflowed the connections on the diodes. I checked and affected tracing for continuity and everything rings out. I don’t see any other visual concerns.

Is there a way to test the op amps without imputing a test signal? What about a method of checking tube pins?

[shooter]

we still have NO clue if it's pre or power amp, so jack the pre out to PA in
otherwise, pick up a scope and trace a signal, your VDC's check out at the PS
not sure "in circuit", like bias volts, current through pa tubes


guessing you swapped tubes

[sluckey]

we still have NO clue if it's pre or power amp,

...If I run into the “Power amp in” input, I get full volume...

I understand this to mean the power amp is fine.

[Cramer1]

we still have NO clue if it's pre or power amp, so jack the pre out to PA in
otherwise, pick up a scope and trace a signal, your VDC's check out at the PS
not sure "in circuit", like bias volts, current through pa tubes


guessing you swapped tubes

If I jack pre out to PA in I still get low volume output.

I have swapped tube positions but have not replaced tubes.

“ your VDC's check out at the PS
not sure "in circuit", like bias volts, current through pa tubes”———-I don’t understand what you mean.

Thanks!

[tubeswell]

I replaced the resistors and reflowed the connections on the diodes. I checked and affected tracing for continuity and everything rings out. I don’t see any other visual concerns.

Is there a way to test the op amps without imputing a test signal? What about a method of checking tube pins?

Are you sure the Zeners are working properly? Check the voltages for a period of time. They need to maintain around +/-16V. If they stray to over 17V or under 15V, suspect them.


The board might 'look' okay but be cooked around the traces. Take the board out and shine a torch through the board. What do you see? Brown stuff everywhere? Those 5W resistors need to be mounted at least 5mm off the board IMO. Or as soon as they heat up, the heat will keep throwing everything else off nearby (including the Zeners).

[shooter]

 

I understand this to mean the power amp is fine.

I took it to mean, put cable from pre out to pa in 

[Cramer1]

I replaced the resistors and reflowed the connections on the diodes. I checked and affected tracing for continuity and everything rings out. I don’t see any other visual concerns.

Is there a way to test the op amps without imputing a test signal? What about a method of checking tube pins?

Are you sure the Zeners are working properly? Check the voltages for a period of time. They need to maintain around +/-16V. If they stray to over 17V or under 15V, suspect them.


The board might 'look' okay but be cooked around the traces. Take the board out and shine a torch through the board. What do you see? Brown stuff everywhere? Those 5W resistors need to be mounted at least 5mm off the board IMO. Or as soon as they heat up, the heat will keep throwing everything else off nearby (including the Zeners).

How long should I check the 16V?

Yes I stood the new resistors off of the board to prevent further heat damage.

[Cramer1]

I understand this to mean the power amp is fine.

I took it to mean, put cable from pre out to pa in 

I did that. No improvement.

[shooter]

that IS a test, just not for your problem, you need a second amp, an mp3 player, a phone, that you can take audio from and stick it into PA in  (whatever device you pick, pick one with volume, "line out" would be great)

[Cramer1]

that IS a test, just not for your problem, you need a second amp, an mp3 player, a phone, that you can take audio from and stick it into PA in  (whatever device you pick, pick one with volume, "line out" would be great)

I have an Orange combo, so run it into my PA in?

[shooter]

ONLY IF it has a "pre amp out", (possibly FX out might work) then plug "that" into your broke PA IN

[Cramer1]

ONLY IF it has a "pre amp out", (possibly FX out might work) then plug "that" into your broke PA IN

Guitar into Input on orange amp, line out of orange into PA in on BDRI achieves full volume.

Guitar into input on BDRI, pre am out to line in on orange amp achieves no sound.

Test point voltages at tubes:

TP3 2.015 VDC
TP6 2.005 VDC
TP9 0.0 VDC

[tubeswell]

... your broke PA IN

 

[tubeswell]

How long should I check the 16V?

Yes I stood the new resistors off of the board to prevent further heat damage.

Anything that's around those resistors has probably had heat damage. Belts and braces would be to replace the Zeners (and the dual rail PS caps) - if the board between the traces/pads isn't arced (in which case you need to do something about that). Change in the supply voltage on this dual power rail will trip the channel-switching transistors - also mucks up the reverb

[shooter]

TP 3,6,9 based on the schematic in reply 15 are AC - signal.  you need a good meter or scope AND a constant signal.


Now we can focus on the pre-amp 


put your foot switch in, plug in guitar, stomp FS on n off, listen to see/hear if relays are a clackin

[Cramer1]

I thought ovals required signal and rectangle TPs were voltages that could be measured without.

Not arguing just trying to understand it all.