TC Electronics BG250 bass combo

[blindboybenton]

Hello

Looking for anyone who has repaired one of these in for repair before ?

TC electronics BG250, Customer reported turned it on one day and this.( See picture ) Only ever gets used in the house
Turn on and some led light up and others don't no operation from front panel buttons. No sound at all from speaker
Is this a fault code ?
The psu is switch mode and has 55v dc out this is the same underload or not. For first 5 seconds at turn on it makes a little noise, but still delivering 55v dc
Outchip is a SMD STA516B. ( Not getting hot ) 5v reg on board ok.. LM340 with about 26 v out.

I have spoken to TC electronics uk and they are about as much help as a chocolate teapot. no schematic or tech help. I can buy a new power amp board but with cost of that with postage + tax + my costs it about 3/4's of the price of a new one.

BBB

[blindboybenton]

The job is closed now. Customer has taken it back and buying another bass combo.

[J M Fahey]

DISPOSABLE Amp

Should come with the new regulation labels:
"No Tech serviceable parts inside"
"Refer disposal to a qualified Garbage Station"

No kidding.

[lalunatech]

For any more recent visitors to this post. I have a TC BG250 here with the same symptoms, PSU working but no output. I have bought a replacement amp board (all SMD and digital with D class amp) from Real Electronics in Sheffield. They are the official UK service centre for TC. They send you a free lolly with your order to make up for the fact that they give no warranty whatsoever on parts that you fit yourself! It wasn't too pricey at £55.95 plus tax. However, when I put the new amp board in, it still didn't work. Turns out it was just bad soldering on the input jack on the front control PCB. Oops, I guess I should have checked that first! Oh well, I might get another one in with a faulty amp some day. Note that the front panel controls (gain, master etc) just send a steady DC signal back to the DSP on the main board. You won't get an audio signal on the Master pot.

[blindboybenton]

Thanks for that. I've had some good results with them but not as much as I will like. Will keep there tel no handy
BBB

[J M Fahey]

Hope at least the lolly was tasty

[dpepe]

Hi,

I have the same issue, same LEDs lit. Same type, BG250 MKI.
I have already checked the PCBs based on the previous posts - thanks for that -, but unfortunately issue not found at the front panel control elements, like the input jack, pots or buttons.
Power Supply seems to be good, it provides 55VDC to the main panel. However, it emits some buzz for 5-6 seconds after switching on.
I also looked at the main panel, all the soldering looks good. Panel interconnections - ribbon cable, audio cable- were tested by a multimeter.

Any idea? Is this a fault code that we can see on the front panel LEDs?
Software update does not work, PC does not find the BG250. Of course, BG250 cannot be booted into update mode....

Thanks,
Peter

[pe.go]

same lights and no operation here :-(
on my amp there is about 120V AC on the J1 plug from the first to the second board.
any ideas to solve ?

[Kolli78]

Hello
can someone please tell me the name of R4 on the power supply board.
Thanks in advance and greetings from Germany Alex

[Jazz P Bass]

R 4 appears to be a NTC (negative temperature coeeficient) Varistor.

It will help alleviate inrush current by going from an initial high resistance, heating up and dropping to a low resistance.

[Helmholtz]

Just nitpicking, but a varistor is a voltage dependent resistor (VDR).
NTC is a negative temperature coefficient resistor.
A PTC is a positive temperature coefficient resistor.

All of them are sintered (ceramic) components and may look the same, i.e. like a ceramic disk capacitor.

[Enzo]

We always called them Thermistors.

[Jon Snell]

TC E digital amplifiers can be a problem especially as most of them don't actually fail, you won't find a fault, because the software gets corrupted and the only cure is to return it to an authorised TCE service department where they will reinstall the software for you at a 75% of a new price.

Not sure what they will do since the new law in the UK regarding availability of spare parts as software, when it fails, must be reinstalled/replaced and therefore is a spare part in the eyes of the law and must be made available for up to 10 years from end of production.
I have had two in for service, both had led lights that didn't make much sense and both needed fresh software.
Both customers bought proper amplifiers and one of them put his on a bonfire in his garden!

[Kolli78]

TC E digital amplifiers can be a problem especially as most of them don't actually fail, you won't find a fault, because the software gets corrupted and the only cure is to return it to an authorised TCE service department where they will reinstall the software for you at a 75% of a new price.

[Kolli78]

sorry Wrong text copied first of all thanks for the many answers I know what the R4 is.
I need the values or the article designation to buy the spare part individually.
since my english is unfortunately not that good, i translated everything with google.
greeting Alex