IC Units Getting Very Hot

[foaminginfection]

I have the Circulator built but am getting no sound out of it other than in bypass. I am still checking a few things, but after doing some audio probing last night, I touched the top two LM13700 IC units and they were burning up. Very hot. The third lower one was fine. So, three questions:

1. Is this normal?
2. If not, could it be causing my 'no sound' issue?
3. How can I tell if I fried them without adding new ones in to destroy?

For some context, I bought the chips off of Aliexpress and haven't had any issues with anything from there yet. Thanks in advance.

 

[Cybercow]

1) No. Not normal.
2) No idea what "it" is. A no sound issue could one or more of several things. Need more info.
3) Need to check the voltage supply across the distribution points. (here it meets the ICs, at the PCB input, after the PCB PS filtering,

Having purchased the chips from AliExpress there is a good chance they're fake. It's rare when AliExpress provides genuine chips. The ones you got may very well be fake and why they are getting hot. So when you test the power supply distribution and input, check first with the chips out of their sockets.

Also, some good, clear, detailed photos posted here would help us better help you. And when/if you post them, you might also include the voltage readings you get at the input, after the filtering and at the ICs and any transistors.

 

[foaminginfection]

Thanks. I replaced the two ICs that were hot with two others that I were pretty sure were legit. Works fine now. Lesson learned about buying ICs from Aliexpress.

 

[szukalski]

Yup, my experience as well. Any IC is a gamble if it's not from a proper reseller. Transistors are starting to go that way as well.. especially the older through hole stuff.