I have a JVC PC-X250 boomer.When its turned on,it has a steady hum to it,kinda like its got a bad ground someplace.It does this in all modes.Any suggestions where too look?

hello again man,has it still got sound ? e.g can you still hear any music with the hum ? or is it just a hum and nothing else ? if its the last one,sounds like the main amp chip has gone..

Oh it sounds/plays good (besides the hum) I programmed the clock and a few preset stations into it and they held in memory,even when it was unplugged for a few hours.The equalizer works,clock works,bass enhancer works,analog/stereo option works and even the remote does its thing.CD player and cassettes play fine.Its just got that low hum to it.It kind of had a mind of its own when I got it.After I bought it,I brought it home,plugged it in and nothing worked.I opened it up,took it too work and let a maint. tech look it over(I work in a welding shop but our maintenance guys are really good with fixin things that somebody else might not be able to)He put a multimeter on it.The transformer is good,AC in plug is good, rectifier board is good and the fuse is good.I brought it back home.W/out doing a thing to it besides reassembling it,I plugged it in and it worked.I'm really not sure if it had a hum to it then bcuz I was so surprised it was working,I didn't pay it no mind too listen for a humming sound.I don't THINK it did but I'm guessing.   

sounds like an ac rectafier may need replacing or ac cap...don't ask me where to look though...good luck...try it on batts...is the hum still there???

With batts in............no hum! Thanks man.That at least gives me a place to start.Now the problem is where to finish   LOL

Before Storminnormin turns up I will offer the following:

Does the "hum" noise emanate from the speakers or the unit itself? Stick your head round the back of the cabinet to check this!

If its from the unit then its most likely from the transformer - replacement would be the only fix here.

If it comes from the speakers, does it increase when the volume is turned up? (Put it on CD or tape without media in, or an aux mode if its got one, to check this without music playing).

If the hum increases when the volume is increased it likely a problem at the power supply stage  - it could well be due to some screening inside the box has been misplaced when it was opened, or maybe something more involved such as an issue with the smoothing capacitors.

It's definitely coming from the speakers.It doesn't get louder as you increase the volume.In CD mode as well as tape mode it also does it.Funny thing is,when I use batts..........nothing.It's clear as a bell.It only does this on AC power.

hi. is it that you could be using a powercord that is putting too much power to the unit?

For that model of boombox i would suggest putting it on a fencepost ...load a double barrel shotgun and....BOOM lol!

or maybe for that model you could put it under your truck and wheel spin on it....that would fix it good and proper