FL2100B Goes Boom (or Zzzzttttt)

[KD6VXI]

Friend brought over an fl2100b.   Bought it sight unseen.   Nice.

Anyway,  need to know either which parts these are,  or if someone can give me a hi res pic of the affected area that hasn't been blowtorch,  I'd appreciate it.

Not a whole lot of money to work with,  so I don't want to burn time up tracing a schematic.   Google parts placement got me nowhere.

Thanks,  in advance.

--Shane
KD6VXI

[N2DTS]

I do not understand.
No money I can understand, why no time to figure out what the parts do, why they blew, and how to fix it right so it does not happen again?

Chances are, you replace those parts and power it up and they will blow again.
Parts do not fry like that for no reason.

[Opcom]

Have some fun tracing the schematic. It seems to be on BAMA.edebris

[KA2DZT]

Looks to be a couple of 1 watt resistors.  Looks like they flamed out.  The wiring around those resistors looks a little messy, you should look at it and see if anything is too close to something else that may have been arcing.  Look at the schematic, it should not be too difficult to see why they burned up.

Fred

I took another look,  looks like the leads of the two resistors are touching each other.

[N2DTS]

One looks like it is not hooked up to anything on one end.

[K4RT]

Neither of the damaged resistors appear to be connected on the right, but maybe the glare is obscuring the connection of the upper resistor.  Can't imagine those resistors were factory installed like that.  Is there a short in the transformer?  Good luck.

[KA2DZT]

One looks like it is not hooked up to anything on one end.

I see the same thing but it's hard to tell from the lighting in the pic.  I see what looks like black deposits on the lead wires, usually caused by arcing right at that point.  If the resistors smoked from overload usually the leads are not blackened

Fred

[Detroit47]

Shane

I will look through  my notes as I recall one of those resistors is part of the meter circuit. Looks like a tube crap out took out part of grid meter circuit. I have seen several of those with similar injuries.
John N8QPC

[N8ETQ]

  Hey Shane,

      Schematic piece/Manual here.  From the parts list there
are only 3 1/2 W R's in it. All the rest are 3 or 10 W.

http://bama.edebris.com/manuals/yaesu/fl2100z/

      I would pull the tubes, replace the parts, Hit the big
Sw. If its ok, check the tubes for shorts, if it has 572B's
look for hardware inside the envelope, I have 2 that have
a small "Spring Like" device floating around in there.  I have
not seen an 811 ever do that but check em anyway.

     If it was shipped to your buddy that's probably what
happened. Use the schematic and trace the part conn.
10 Minutes there will save grief...

GL

/Dan

[W3RSW]

Both those resistors look like kludged in mods Gone wrong.  Various old solder splices on leads and perfectly straight, pre soldered leads don't add up to a completed factory built circuit.  To say the least.  I magnified the image with this ipad. Amazing looking defects.  Compare the whole area with Dan's good amp.

Also look at .01 uf (ceramic disk) bypassed coil. (ip meter shunt?) That's been fried too or has shown excessive heat.  Solder spewed everywhere.  I think I'd replace the entire environs with factory spec. rewiring and components like Dan's, then start measuring away. Are there resistance check tables that someone could email?

Don't replace tubes and fire up until circuit is replaced and all cold checks are ok.
BTW, It's almost impossible to even order parts without understanding the circuit. 

[flintstone mop]

Here's a better Google picture of the affected area. Does not look like what we see from the OP that it is kludged. It looks a little suspicious, though.


http://www2.ocn.ne.jp/~yino/jpg/fl-210_a.jpg

Fred

[Opcom]

Shane

I will look through  my notes as I recall one of those resistors is part of the meter circuit. Looks like a tube crap out took out part of grid meter circuit. I have seen several of those with similar injuries.
John N8QPC

Could someone have put a regular 300-500V resistor where a high voltage one belonged? Common new mistake is to do that, not knowing that >500V or so a special part may be needed, or, to put several low voltage ones in series to divide up the voltage. Might have also put too small a wattage and when they cooked they blew up.  Are those the HV capacitor equalizing resistors?

[KD6VXI]

Well,  got the 2100 going.   Burned resistors and shunt in I plate meter....   As well as a burned plate meter.   Rebuilt the shunt and it's operational.

So,  now to find a plate current / swr meter for said amplifier.   And a top case.

And it ended up being a gimme :-)   So,  now I'm the proud owner of a 2100 that went bzzt....

Anyone have a meter and top case?

--Shane
KD6VXI

[N8ETQ]

   Sorry I don't have a meter but a couple back to back 1N4007's
 would probably have saved it. Strap a couple across your new one
 and you won't have this trouble again.

GL

/Dan

So,  now to find a plate current / swr meter for said amplifier.   And a top case.

Anyone have a meter and top case?

--Shane
KD6VXI