200s problems

[RocknRoll]

I have a really beat up 200s that I bought off ebay that was super rusty and had many parts missing. I fixed it and it was working great until one day I turned it on and all the low end was gone from the sound, and it was much quieter. It still sounded cool but not cool in the way a 200s should sound. After playing it like this for a few minutes it just kicked in and all the sound was there again. This problem got worse over time and it eventually took like 30 minutes to work. I noticed that if I flicked the standby switch and heard static noises it would work normally once they went away. If there was no static I would get the quiet no low end sound. I changed out the old capacitors and the problem only got worse. It takes way longer to kick in, I also messed something up and have a lovely hum now. Does anyone have any idea what is going on here? It's really strange. I am going to put the old caps back in because they sound better when it is actually working but this problem is beyond me. I don't know anything about why amps break I just understand how to read a circuit diagram and solder things together safely. Once I get it somewhat working again I can maybe post a recording to help people understand what is going on.

[mckinnon audio]

  Hi there,sounds like you have some bad connections in the preamp,maybe around the bass control,bass boost section.The hum could be a signal ground that's opened up,good luck,Mel.

[Greg_M]

You've checked your tubes I presume?
Wiggle your resistors. I had a couple that were cracked and when I touched them they broke apart.

[loudthud]

Check the Bass Boost switch.