Blackstar Reverb Getting Hot

[tdlunsfo]

I have a HT Studio 20 back on the bench. Customer states that after the amp is on for 3 hours there is loud crackle noises. I let her run for awhile on a dummy load and sure enough while turning the reverb pot I get crackle. I pulled the chassis and the heat coming off this thing was impressive. Looking at the schematic the reverb is solid state and the chip is IC8 in the pic. I put my heat gun on the circuit and after about 10 mins the symptoms return. Removing my heat gun and placing my fingers on IC8, cooling it down, the noise stops. Now how to proceed, how would you all continue here? I think this is a heat problem as the IC is sandwiched between a heat sink, tubes, and a bunch of power resistors. I am thinking some kind of stick-on heat sink or maybe a simple 120v fan. Thoughts?

[Jon Snell]

IC8 is a busy little chip, twin a/d convertors twin messing with the signal and twin d/a convertors set out as a reverb/echo effect.
I would replace the chip as placing a heat sink on it in such a confined space will only buy you an hour if you are lucky.

[tdlunsfo]

So I guess we are saying that it should be able to take the heat in this location and the chip is defective? I am not setup well for SMD but have been able to do it in the past. Just seems mounting a fan would be just as simple. Decisions, decisions..thanks for the feedback.

[Jon Snell]

Afraid so. Replacing the chip is the only option my customer would get as I don't want to see it again in a few months time with a disgruntled bad mouthing customer.

[tdlunsfo]

I'll have to see if I can even source this chip, Spin FV-1. Never worked with Blackstar before, maybe they will supply it. The store swapped out the amp for the customer, so it's really their call on how to proceed.

[Jon Snell]

http://www.spinsemi.com/contact.html
They can be very helpful.
http://www.spinsemi.com/distributors.html

[tdlunsfo]

Replaced the chip and ran it on a dummy load for 5 hours. No issues. Thanks for the assistance.