Bugera 333XL - where should these loose resistors go?

[mikeydee77]

Just opened up a client's faulty amp and found two 150K resistors lying inside the chassis. They are 150K and I would say 2 watt judging by the size. From the pre forming and solder on the legs it looks like they were tagged onto the PCB at some point but I have no idea where.

Any Bugera experts out there?

Here are some pictures of the resistors in questions in case it rings a bell

And the amp itself


The amp itself is working fine right now although it came in with the two T1A fuses blown, which I presume are for the filaments although I don't have a schematic just now so can't be sure. So just trying to work out if these resistors are related to that fault or just a separate bit of fun.

[g1]

Like you said, from the amount of solder on the leads, it looks like they were tacked on to something, rather than standard board mounted.
Was thinking maybe bleeder resistors for the filter caps, but from the schematic it seems they are 220K's.
Here's a link to the schematic: http://www.elektroda.pl/rtvforum/download.php?id=456941

[mikeydee77]

Like you said, from the amount of solder on the leads, it looks like they were tacked on to something, rather than standard board mounted.
Was thinking maybe bleeder resistors for the filter caps, but from the schematic it seems they are 220K's.
Here's a link to the schematic: http://www.elektroda.pl/rtvforum/download.php?id=456941

Thanks g-one - that's great but I can't seem to find those resistors on there. Perhaps this is a mod that came later on. I did wonder if these were tacked on to something too but have fallen off due to heat in the near vicinity weakening the joint.

[Enzo]

I am not aware of any 150k power resistors in this amp. There are a couple 150k plate load resistors in the preamp, but since you report it works, I must assume there are no missing plate resistors.

Much as people like to bash Behringer, they don't just tack stuff onto other things.

perhaps someone was messing with mods and left them loose by mistake.

[mikeydee77]

Thanks Enzo I was hoping you would stop by.

After posting I did find a mod to the amp of sorts. There are two LED modules attached to the inside of the amp's cab. The owner knows nothing about them or even if these lights work. So given your comments and the circuit drawing that g one was kind enough to suppl it sounds most likely that the two resistors are related to the two LED modules but have dropped in to the chassis somehow.


mike