Spider 3 - 75 Watt Combo Squealing
Posted 31 December 2013 - 10:42 AM
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 ?
Posted 10 January 2014 - 03:05 PM
Have you found a solution, before I open it up?
Posted 11 January 2014 - 12:45 AM
Posted 20 January 2014 - 05:41 AM
Posted 13 December 2014 - 12:35 PM Best Answer
Posted 14 December 2014 - 04:49 AM
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
Posted 14 December 2014 - 06:51 AM
Posted 17 April 2015 - 03:04 AM
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.
Posted 17 April 2015 - 03:06 AM
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.
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?
Posted 06 May 2015 - 11:48 AM
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
P/N 50-02-9308-1 from fullcompass.com
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
- 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.
Posted 31 July 2015 - 12:21 PM
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.
Posted 04 August 2015 - 12:14 AM
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!
Posted 05 August 2015 - 10:51 AM
My Spider is back to life . 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.