Fender Blues Deluxe Reissue

[Electric Ladyland]

Hello, I recently purchased a Blues Deluxe reissue. I believe it dates back to 2004.

I took the back panel off to check the condition on the circuit board and to check on the caps etc. On doing so, the only issues I noticed were at D13 and U3. Can anyone shed any light on what's going on here, and should I be concerned?

Many thanks.

[g1]

You are probably referring to the flux residue and it is not a concern. Carefully inspect all the solder connections on the tube sockets. It is usually worthwhile to resolder them all if there are any that don't look pristine.

[Electric Ladyland]

Thanks for the reply g1. Yes I think you are correct that the browning is from flux residue. There is also a bit of moisture on the board which I am guessing that the flux is attracting?

[g1]

Is it moisture you can wipe up with a swab? I see more clear flux residue around those 2 parts.

[Jon Snell]

I would say that those two components have been reworked or replaced and either 'no clean' flux wasn't used or the board was not washed afterwards.
The diode looks a little large for a 1n4006 from your photo. Not that it matters.

[loudthud]

A friend of mine once ask, "Does No-Clean mean you don't have to clean it, or that you can't clean it ?" LOL! I use either straight alcohol, or spray-on board cleaner in a aerosol can top and cotton swabs. An acid brush helps breakup large areas of flux and the swabs mop it up.

[Mick Bailey]

The diode looks a little large for a 1n4006 from your photo. Not that it matters.

D13 is a 1N5353B Zener.

[Chuck H]

the only issues I noticed were at D13 and U3. Can anyone shed any light on what's going on here, and should I be concerned?

Is the amp having a problem in operation? That would be a concern, but not necessarily regarding those components. Being from 2004 I might be more concerned about those old, gray IC electrolytics. They don't have a good reputation with respect to longevity or long periods of stasis without charging. If the amp displays any signs of power supply filter problems I would replace all the electrolytics (including the bias supply and low voltage supply caps). If the brown smudge around the solder joints after you're done bothers you then take the advice on cleaning.

[Jon Snell]

D13 is a 1N5353B Zener.

Whoops, I was looking at D3.

[52 Bill]

What I see is a slight discoloration of the solder joint. These diodes get pretty hot and I've seen the solder turn dull grey from temperature swings. Sometimes they actually become a problem and sometimes they just look like cold joints.

If I have to take the board out for something else, I will desolder and resolder these joints just as a precaution.

Just my $0.02

[Electric Ladyland]

Thanks for all your input, it is appreciated. It's reassuring to know that there is nothing to worry about with regards to the OP.

No, there are no issues with the amp. However as it's around 18 years old (previous owner said he hardly used it and it sat lying around for the majority of time) I just wanted to check how it's holding up.

I will take the advice of cleaning when I next open up the back - I will also see if it's actually moisture or not.

Thanks again for all of your help.

[Yadi123]

Sorry for resurrecting an old thread. I have a Fender Hot Rod Deluxe, similar to the OPs Blues Deluxe. I am replacing caps ,resistors (Fromel Mod) and diodes. My question is the CR13 and CR14 near the PS resistors that burn the board: My schematic calls out 1N5353B zener diodes; however, a replacement 1n5353B is dimensionally smaller than what is on the board. I can make out "5353" on the original diodes. The replacement is 16V 5W 5%, which is what the service manual calls for....16v 5W 5%. What does the different size constitute and am I risking by replacing with a physically smaller diode?

[The Dude]

5 watts is 5 watts. The replacement diodes are probably just from a different manufacturer. I'm curious though,...... The mod has you replace a diode with the same part number? I don't see the point unless the original diodes are bad. IMO, it's a colossal waste of time, creates work, and risks circuit board damage for no apparent reason (unless I misunderstand what's going on here). The only advantage might be if you leave the leads longer and stand the diodes off the board to prevent heat damage to the board. However, I've never seen the boards burnt in those amps- maybe just some slight discoloration.

[Yadi123]

Thank you for the confirmation of substitute. My original post wasn't very clear: The mod doesn't have me swapping like-for-like and I was just rattling off my to-do-list. The diodes are a different story and are next to a couple of 5 watt resistors that I need to replace (raise off the board) because they get extremely hot. These boards do have well known issues with heat at the 5 watt 470 ohm power resistors (r78 and r79) and affecting the traces of nearby diodes as well.

[The Dude]

....These boards do have well known issues with heat at the 5 watt 470 ohm power resistors (r78 and r79) and affecting the traces of nearby diodes as well.

I don't completely disagree with you, but FYI Fender rectified this problem early on with a tech bulletin instructing that those resistors be changed to 470Ω. The early models came with 330Ω. I haven't personally seen issues since. In other words, if the resistors are 470Ω and not 330Ω, I wouldn't worry about them.