CAUTION! You always add acid to water, not the other way around! If you google why, you find:
A large amount of heat is released when strong acids are mixed with water. Adding more acid releases more heat. If you add water to acid, you form an extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container!
SO.....BE CAREFUL IF YOU ARE POURING STRONG ACID DOWN YOUR SINK DRAIN.
I once cleaned the battery corrosion on a Bally MPU using acid and small acid brush. Let it set for less than a minute and rinsed the board in the kitchen sink. Worked like a charm.

My one and only scope I ever owned was a Heathkit I built in the 60's. If yours was ancient, mine must have been prehistoric. OMG.

You are still using yours?! Haha, my Heathkit is long gone. The newer scopes are really nice....smaller and lighter. But I've just gotten by all these years without one, so have never replaced it.

Using a credit card to pay in China is probably more of a hassle with them than paying with Paypal as he suggested. (I've been to China 9 times and know some of their hassles). If you pay with Paypal you are covered (like using a credit card) if you don't receive the merchandise, or if you need to return a defective product, etc. If you don't want to open a Paypal account, and you can't get the purchase with your credit card, I'd be happy to pay for it with my Paypal account and you can reimburse me with a check in the mail.

P.S. I'm enjoying your thread.

Yep. Amazing. I've bought items that cost less than a dollar and included free shipping from China! Geez, I can't even ship a padded first class envelope across town for that! Good old government subsidized shipping.

What a bummer. I was learning a lot too and enjoying this thread.

Noooooo!! What I learned was that I don't ever want to replace surface mount components! Especially those IC's!