davidiancross Posted December 31, 2013 Share Posted December 31, 2013 Hi my spider 3 / 75 watt combo is around 7 years old but has only been used as a back up amp with around 3-4 hours in total maximum use and never gigged during its lifetime, The other day I turned it on and everything looked OK until I plugged my guitar lead into the input and it emitted a high pitched squeal from the speaker, I changed the lead and same result, I attached a guitar to the lead and plugged in, same result and no sound from the guitar, with or without the FBV Express short board attached, I did a factory reset, no change, it is when the jack makes a contact inside the input socket when the noise starts, there are no abnormal smells, all the panel lights up as it should, any ideas anyone apart from throw it in the bin ? regards Dave C Quote Link to comment Share on other sites More sharing options...
bchiodini Posted January 10, 2014 Share Posted January 10, 2014 Dave, I have the same problem with an identical amp. It doesn't seem to matter what I put in the 1/4" jack. I tried a plastic rod and the amp squeals. The rod does not need to contact anything inside the jack, simply be inserted a short distance. Have you found a solution, before I open it up? Quote Link to comment Share on other sites More sharing options...
davidiancross Posted January 11, 2014 Author Share Posted January 11, 2014 No I haven't got a solution as yet other that the local boutique amp maker, Maughan amplification said they would bench test it for £30 , however the magazine "Guitarist" are to feature my problem in next months Q&A section of the magazine so watch this space. So whether that means the end of January or end of February magazine, I'm not too sure, I may just take it to be bench tested and get a quote for repair or wheelie bin! Regards Dave C Quote Link to comment Share on other sites More sharing options...
bchiodini Posted January 20, 2014 Share Posted January 20, 2014 Dave, Replacing the main board fixed the problem for me. It was purchased from fullcompass.com. $92 US. Troubleshooting revealed, no 5 volts on the input board. The 5 volts is sourced on the main board, but I couldn't find an accurate schematic to trace the problem any further. I suspect a bad resistor between the 5 volt regulator and the input board. Bob... Quote Link to comment Share on other sites More sharing options...
SVHOKidd Posted December 13, 2014 Share Posted December 13, 2014 My amp is making the same noise, like fingernails on a chalkboard. So replacing the main board solved your amp'so problem? Now we are talking about the board with the jack board attached via ribbon cable? 50-02-9308-1 ? Quote Link to comment Share on other sites More sharing options...
davidiancross Posted December 14, 2014 Author Share Posted December 14, 2014 Yeah it was the main board, was going to cost more than the amp was worth so I dismantled it, sold it for spares and bought a Blackstar Quote Link to comment Share on other sites More sharing options...
SVHOKidd Posted December 14, 2014 Share Posted December 14, 2014 Ok. I'm looking into a Marshall or Fender. Something with a longer warranty. Quote Link to comment Share on other sites More sharing options...
SVHOKidd Posted December 17, 2014 Share Posted December 17, 2014 I definitely won't be a returning Line 6 customer. Quote Link to comment Share on other sites More sharing options...
PARISICC Posted April 17, 2015 Share Posted April 17, 2015 Hey everyone, My Spider III 120 combo has been squealing and I am probably going to try to replace the board as a couple of guys here seemed to have success with. Did any of you take videos of this to document the sound? Just to confirm, my amp turns on fine, I can switch channels, etc. The second that anything is inserted into the input jack (or even just makes contact), that horrible squealing comes. So I can literally just take one end of a cable and touch it to the inside of the jack to produce the sound. If I bear with the sound and plug the guitar in too, it doesn't matter...and I can't hear the guitar. Volume knobs, channel switching...nothing changes the volume or pitch of the sound. It seems like fullcompass.com has a return policy so I guess it's worth the ~$100 gamble, since all I would have to do is pay for return shipping and a restocking fee. Anyone have anything to say or add? Line 6 Tech Support is lame and a local certified technician/store wanted $60 to just look at it and said all his Line 6 customers are unhappy because stuff breaks and it's hard to diagnose...and then sometimes parts aren't even available. Quote Link to comment Share on other sites More sharing options...
PARISICC Posted April 17, 2015 Share Posted April 17, 2015 Dave, Replacing the main board fixed the problem for me. It was purchased from fullcompass.com. $92 US. Troubleshooting revealed, no 5 volts on the input board. The 5 volts is sourced on the main board, but I couldn't find an accurate schematic to trace the problem any further. I suspect a bad resistor between the 5 volt regulator and the input board. Bob... Also, Bob, I was curious as to how you figured out the troubleshooting process. Or could you explain how to do this or what terminals to check for 5V? Quote Link to comment Share on other sites More sharing options...
PARISICC Posted May 6, 2015 Share Posted May 6, 2015 Just so everyone looking at this knows, replacing the main board solved my problem too. I took the $92.40 gamble from fullcompass.com (not really a gamble since you can return the board) but it worked out. Amp seems to be back in business. Thanks to everyone above for the indirect help. To recap, I have a Spider III 120 and the amp would make a horrible squealing sound any time something touched the input jack. I wouldn't even have to fully insert a cable. This is also assuming the amp was turned on. Volume, gain, tone controls, etc, did nothing to the sound or volume of this squeal. I read these posts and fixed my amp. Quick rundown of how to replace the board...and sorry I forgot to take pics Parts required: P/N 50-02-9308-1 from fullcompass.com Tools required: phillips head screwdriver 2ea thin blade screwdrivers 15mm (?...forget the exact size I used...I brought a bunch with me from the garage) socket, and wrench if you desire box cutter, exacto knife Process: disconnect speaker wires. if you have more than one speaker, note positions/colors of each wire. you may also want to lay the amp/cab down on its face. unscrew 2ea (1 per side) mounting screws on either side of the amplifier assembly. these screws go through the cabinet into each side of the amp tray. unscrew the 4 screws holding the amp tray to the top of the cabinet. lift the amp assembly out of the cab use the 15mm socket to loosen and remove the nut on the front of the input jack. this will enable the input jack to slide out through the back. use whatever knife or cutting device you found to gently break the seal of hot glue that holds the smaller of the two electrical harnesses into the main board. pull that harness out by hand. use two thin-blade screwdrivers to put pressure on either side of the large ribbon cable harness and remove that harness. remove the 4 (or 5...i forget) screws holding the main board onto the amp assembly install the new board and use the reverse of this procedure to button the amp back up *the new board i received had a breakable tab/green section of extra board. You can run the wires from the smaller harness underneath and to the side of this tab so you don't have to break it off. I followed this method in case the main board was not the problem...then I would be able to return the board in original condition. ...and no, I didn't try to return my old board for a refund! Good luck all. Quote Link to comment Share on other sites More sharing options...
pecorporation Posted July 31, 2015 Share Posted July 31, 2015 For those of you willing to go to component level, you might want to look for a short on the main pcba #35-00-0308 at capacitor C20. It is a 6.3VDC 1000MFD cap which, I'm guessing, gives up the ghost after a few years of handling that massive +5VDC supply. I replace them with a 16VDC cap just for good measure. If that cap is shorted, it probably also took out/burned resistor R54, a 5.11 ohm surface mount 1/4watt on the underside of the same board. I had these parts in stock but a likely source to obtain them would be Mouser. Good luck! 1 Quote Link to comment Share on other sites More sharing options...
Framer Posted August 4, 2015 Share Posted August 4, 2015 Hello, Thank you Pecorporation, i just experienced the same problem on my Spider II (main board 50-02-0220-1) 1000µF 6.3V capacitor shorted and R54 burned so i couldn't read the value on it any more. I could not find the schematic anywhere on the net so i was about to replace with a 4.7 Ohm. You gave me the right value. I already replaced the capacitor with a 16V one and will also replace the 7805 regulator, although it looks good, since believe i saw some smoke there. The defective capacitor is very small for a 1000µF 6.3V and micro capacitors are not very good over time, it is a pity because there is plenty of room in this amp! Quote Link to comment Share on other sites More sharing options...
Framer Posted August 5, 2015 Share Posted August 5, 2015 My Spider is back to life :D. Thank you. By the way, i found actually several Spider schematics on the web, the main board (DSP) is almost the same in all of them but these power components do not appear on any. Text descriptions refer to R53 R54 but not their value. I think this problem is or will be quite common, so this thread could help many persons. However, this issue does not really match the title and some persons may miss the fix. Might be worth creating a new topic for it. Edit: Found another topic titled "Spider 3 no sound but powers on" more likely to be the symptom, and updated it with this info. Quote Link to comment Share on other sites More sharing options...
SVHOKidd2 Posted February 15, 2021 Share Posted February 15, 2021 Well it’s been a few years since I ( SVHOKidd ) posted. After I was disappointed with the Spider iii failing I bought a Fender Mustang iii in 2014 and it’s still going strong. I kept the Spider iii and recently dug it out. I rediscovered this thread. After reading pecorporation’s post about the cap and resistor, that’s what failed with my amp. I searched for a replacement card to no avail. I followed pecorporation recommendation and ordered a cap and resistor. I figured I’d give repairing it a try. If it doesn’t work out I’m thinking about building a tube head to replace its guts. Quote Link to comment Share on other sites More sharing options...
psarkissian Posted February 16, 2021 Share Posted February 16, 2021 Squealing,... Loose ground lead or intermittent solder point on the negative side of a filter capacitor, somewhere in the analog section. with the lift in the ground plane, there is a volt difference, allowing the partial and frequency fold back from the digital clock, to show up on the audio line. Loose cable connection inside can produce the same lifted ground plane and squeal. Make certain your amp is registered in your Line 6 account, then log a Support Ticket. This is not a self repair problem and should be dealt with by an experienced Line 6 authorized service center technician who knows the product. Quote Link to comment Share on other sites More sharing options...
SVHOKidd2 Posted February 16, 2021 Share Posted February 16, 2021 I registered it with L6 back in 2008 and to be honest for being as old as it is. Paying to have it shipped out and repaired would cost more than it’s worth. If it works after replacing the resistor and cap...great. If it lets out the magic smoke oh well and here comes a tube kit. But thanks for the advice . Quote Link to comment Share on other sites More sharing options...
radmaniac Posted February 26, 2022 Share Posted February 26, 2022 Thank you "precorporation". After replacing C20 and R54 as you suggested, my squealing 120w 2x10" became fully operational again. Thank you! Quote Link to comment Share on other sites More sharing options...
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