HELP! T-202 crackling & noise

[Papus]

I recently decided to try an experiment after seeing those ghastly hipsters butchering scanners to create guitar chorus units.....

I took a tap from the input pin of the vibrato/chorus board and plugged a Strat straight in.
It worked nicely, sounded good, and the volume level of the Strat was well matched to the tone wheels (I'm using low output Lace Sensor Gold pickups).

I noticed when I reverted back to playing the T-202 that a persistent crackle and noise (combination of hum & hiss) is now present.

I fear the guitar signal somehow bled back into the recovery amp via the input pin on the vibrato/chorus board which originates at the lower & upper manual recovery amp outputs to the vibrato tab, potentially damaging a component.

HELP!

I don't know what damage I've done.

Anyone else experienced a crackling T-series?

I'll try to post before and after audio samples in the next day or two

[nonreverb]

Crackling in a T series is not uncommon. I'll bet it's more likely due to dirty or loose connectors on the main board. Just being back there connecting the guitar cord could have started that process happening.

[Analog]

Crackling in a T series is not uncommon. I'll bet it's more likely due to dirty or loose connectors on the main board. Just being back there connecting the guitar cord could have started that process happening.

Yep I remember my T202. I only had to look at the main board and it would start crackling. I cleaned all the pins, reflowed their solder and crimped all the connectors for a tighter fit. That helped alot.

[Papus]

Mystery solved....... sort of.
I reassembled the T202 and moved it back into position against the wall next to my Leslie 122 in readiness for a huge party, and to my surprise when I fired everything up the noise and crackle was completely gone.
I can only assume a loose contact or component was jolted back into position during the move - at any rate I'm not complaining :)

Thanks for the advice

[wayshot]

Be prepared that the crackle might reappear anytime. It's a T, y'know :)
I did some work on my T-500 last weekend. Tried changing an electrolytic cap on the auto-chord board. The crackling seemed to have gone after the surgery - but reappeared again a while later. Found that it probably appeared at the recovery/non-vibrato preamp board. Replaced the e-cap on the board and the transistors for the last two stages. Turned on, less crackle than before. Played for a while, crackle seemed to be gone. Played a bit the next day, still very little or no crackling.
Next thing is to replace the filter caps in the power supply to try to defeat the mains hum, but I need to source some good caps first.