fender deluxe 90 DSP problem

[shimshon]

hi,

i've been having an intermittent problem with my fender deluxe 90 DSP amp. it seems as though when i drive it too hard (volume no higher than 5 or 6) the signal randomly drops out, usually when i'm on the overdrive channel or using a distortion pedal. lately, however, it's been happening more frequently, even on the clean channel with a clean signal going in, to the point where i can't practice with my band because it's so choppy.

i opened her up hoping to find a burnt out resistor or some other failed component but didn't come across anything.

has anybody had this problem or know what to do about it? i'm willing to do the repair myself if someone knows the solution, but it's just not worth it to bring it to an authorized repair shop and pay 100+ bucks.

thanks,
vito

[Enzo]

Plug a spare cord from preamp out to power amp in jacks. If that restores the sound, the power amp jack needs service or replacement.

Or ball up your fist and whack the amp hard on top. If that makes it stop doing it, or if it makes the symptom start, or for that matter of the amp reacts in any way, there is a loose connection somewhere. Possible cracked solder under something like a jack or control or large resistor.

[shimshon]

aha! banging on top of the amp reproduced the symptom almost every time, so it should be pretty safe to say that it's a loose connection.

it happened most frequently when i hit it right behind the handle strap. i'll look around that area for bad solder joints.

thanks enzo.

[abav]

I have repaired many of the deluxe 90 dsp's, and a lot of the time the culprit is either a broken solder joint on the effects send/return board, or bad solder on u10 (the regulator with the heat sink fins coming up from it).

[Enzo]

It could be anywhere. it is just that hitting it there is most efficient at sending a mechanical shock through the system. Of course it could be exactly there.

Pull the chassis, connect it to a speaker, plug some sort of signal into the input, and flex and probe the innards until you find what's loose. A wooden chopstick from the CHinese reastaurant down the street is great for this.

Common points are jacks and controls along the panel, and the rectangular cement powr resistors on the board.

And conceivably the speaker wires or speaker itself could be involved.

[shimshon]

hi,

finally got the amp open and ready. what should i be looking for as a sign of a bad solder connection?

[shimshon]

i believe i found the problem. there were two loose connections: U10 and its heatsink. i resoldered them and am about to put it back together. i hope that was the problem, this amp was a huge pain in the ass to disassemble. keeping my fingers crossed...

[dukeofurl]

I have repaired many of the deluxe 90 dsp's, and a lot of the time the culprit is either a broken solder joint on the effects send/return board, or bad solder on u10 (the regulator with the heat sink fins coming up from it).

Top marks!!!
Just got one of these to look at... problem.. bad joints on send/return.

I LOVE this forum!!!!

[Ian59]

Fender deluxe 90 dsp problems

Top marks!!!
Just got one of these to look at... problem.. bad joints on send/return.

I LOVE this forum!!!!

My amp had loud popping plus excessive hum and wild volume levels. Re soldered all the 5watt cement resistors and reflowed all solder points I could see. Amp works okay for a short while then problems started again. Replaced all cement resistors - popping stopped but still excessive hum. Eventually traced problem to C67 47uf capacitor. Didn't have 50 volt rated one so slipped 68uf 50v item in instead. Amp works perfectly now- at long last.
Hope this is of help to anyone with similar issues.

[MEKEELS MUSIC SHOP]

How do i open chassis on delux 90 ? please help

hi,

i've been having an intermittent problem with my fender deluxe 90 DSP amp. it seems as though when i drive it too hard (volume no higher than 5 or 6) the signal randomly drops out, usually when i'm on the overdrive channel or using a distortion pedal. lately, however, it's been happening more frequently, even on the clean channel with a clean signal going in, to the point where i can't practice with my band because it's so choppy.

i opened her up hoping to find a burnt out resistor or some other failed component but didn't come across anything.

has anybody had this problem or know what to do about it? i'm willing to do the repair myself if someone knows the solution, but it's just not worth it to bring it to an authorized repair shop and pay 100+ bucks.

thanks,
vito

can you help me remove chassis , I removed obvious screws , still having trouble , thks

[Enzo]

Four screws out the top. Maybe a screw or two into each side. Ought to be free then. SOmetimes the chassis sticks to the tolex or the glued on foil, you get a small screwdriver in between the pop it free. Sometimes, especially on side screws, the chassis is folded up with a threaded insert into it. When the bolts are tightened, that chassis flap gets pulled into the wood - it spreads some. This wedges the chassis in place. That is a pain.

[Jazz P Bass]

Yeah, and the front panel pinches at the speaker grill.

Please do not forget to remove the speaker lead wires before removing the chassis.

[MEKEELS MUSIC SHOP]

thank you

Plug a spare cord from preamp out to power amp in jacks. If that restores the sound, the power amp jack needs service or replacement.

Or ball up your fist and whack the amp hard on top. If that makes it stop doing it, or if it makes the symptom start, or for that matter of the amp reacts in any way, there is a loose connection somewhere. Possible cracked solder under something like a jack or control or large resistor.

read your blog last night at 3 am and spend 3 hours today and and I fix the problem.

[pecorporation]

Here's a video that tackles that loose U10 issue:

https://youtu.be/lO5OBs5vI8A