I changed my electro acoustic bass strings to rotosounds phosphor bronze round wound strings. But now my bass won't play through my amp I'm happy with the sound of the strings just pissed about this.

What could be causing it :/ the plastic thing in the bridge did come out and I put it back in and everything with the metal strip under it properly. I also popped the pegs out from underneath with my hand could I have damaged something?

Any help will be appreciated worried now.
You've broken the piezo, simple as that. Bst case scenario is that you've snapped a wire or some solder, which is easily fixed; the worst case scenario is the pickup itself is broken in which you'l just have to buy a new one.
Would that of been from pulling the saddle out by accident or putting my hand in to pop pegs out? And how much would a new one cost and I wouldn't be able to install it myself as I'm not good with stuff.
If you don't want to fix it yourself then just take it to your nearest guitar shop and ask them what's wrong, they should be able to tell you what's wrong for free.

Also: I'd rather pay for a few ****ups and learn from them than give up after a first try.
Well if I had to buy them would they be like over 100 pound and also my strings look slightly different heights is that normal for one to be slightly lower or is that bad I have no fret buzz or anything. My strings are obviously a bit twangy as there new but no buzz. And how hard is it to install a pickup and is there anyway I can check what's wrong is there a guide anywhere I'll give it a go when I next change strings I don't need to amplify at the moment but want to next month so.
Update: I loosened my strings down enough to fiddle with my saddle and when I was tuning it the preamp started working the tuner bit got the E in tune but once I started tightening the rest it didn't work anymore and then the E stopped showing up on the built in tuner. Didn't test it through an amp unto after.

Does this mean something is just sitting wrong? I don't know what I should try now but if it was reading the E for a while until I thightened rest it must be working a little.
that sounds really strange. if you made this far and can't figure it out, i'd take it to a professional
I'll get it checked next month havnt got money at the moment. Also I won't damage further by playing it will I? And is it normal to have the d and g string a little lower than E and A I know the saddle is lower that side because strong thickness maybe it's always been like that. Lately I've got the bad habit of examining everything to much. But yeah it is weird how it picked up the E for a moment. When I fiddles with wire the amp made a fuzzy noise like when you plug in at first with the amp on. I'm site it's a loose wire connection or something. Hoping should be a cheap easy fix. If not it will stay acoustic.
Intermittent issue. Spaz is calling it.

Be ready for a new Pickup, but it is just not right that it would fail because you changed a String. Give the Repair shop a call and ask some questions. Search on line. This does not sound right. Do you have any warranty?

If your hand moved a wire it would be gone flapping around in the body and nothing would make any noise.
Ibanez BTB 1006 Fretless and 405 (no Barts)
456 & 455(w/Barts)
Genz Benz NeoX400 112T & NeoX 112T cab.
Digitech BP-8 (x2)
Yamaha PB-1
Boss: SYB-5, PS-2, OD-20, EQ-20, PH-3,BF-3, CE-20, DD-20
Morely A/B