No idea what the heck I did to this. It will bypass but once switched on I get nothing. My voltages are way out of wack from the ones that I found from another post. I used a Road Rage to change the power input. This just blows me away. Maybe I have the Road Rage hooked up wrong but I followed the instructions. Any ideas on how I screwed up this 25 part build :o? Here are the voltages I am getting:
Q1 Q2 Q3
E - 8.56 E - 8.66 E - 9.15
B - 8.46 B - 8.56 B - 9.10
C - 8.16 C - 8.13 C - 9.10
(http://i1143.photobucket.com/albums/n625/cmsgt1997/bee1.jpg)
(http://i1143.photobucket.com/albums/n625/cmsgt1997/bee2.jpg)
(http://i1143.photobucket.com/albums/n625/cmsgt1997/bee4.jpg)
(http://i1143.photobucket.com/albums/n625/cmsgt1997/bee3.jpg)
Uhhh ... you need to put a chip into the road rage ...
Ok Jon. I feel real stupid. If you go back to page 4 of the build doc it says to solder D1, D4, C1, C2, C6 and C7 and omit everything else for the voltage change. That's why I didn't put one in. I hope I didn't fry the transistors. Thanks for the help.
Quote from: BrianS on May 04, 2015, 10:21:44 PM
Ok Jon. I feel real stupid. If you go back to page 4 of the build doc it says to solder D1, D4, C1, C2, C6 and C7 and omit everything else for the voltage change. That's why I didn't put one in. I hope I didn't fry the transistors. Thanks for the help.
Nah the trannies will be fine
Put a LT1054 in and still the same. Get bypass, switch on nothing.
Measure your voltages at the -9v pad without it connected to the circuit.
I don't understand what you mean by not connected to the circuit. Could you please explain what you want me to do? Sorry for being a pain.
Disconnect the road range from the bumblebee board. Make sure the road rage is working. There's no point in troubleshooting the fuzz if the power supply isn't working properly yet.
Ok. Will do when I get home today. Thanks.
I am getting a -9.1v.
okay. Reconnect it to the PCB. Are you getting -9V on the power rail, and 0V on the ground points?
Yes. -8.89 and 0 on ground Pts. all transistors are still registering positive 9s.
The only way that can happen is if you have crossed the -9v and G wires from the RR to the BB board or if you have reversed the leads on your DMM when measuring voltages. Make sure that -9v on the RR board goes to -9v on the BB board and G to G. With your DMM use the black lead for ground and the red lead to measure the collector voltages on the transistors. You should now read negative voltages.
Screwed that up. Now the -9 from RR is going to the -9 on BB and G from RR to G on BB. Now I get a 0 on all transistors except a -.05 on Q1 and Q3 base. Still bypass but zero when switched on.
can you post some pics again from pcb up / down and the wiring (especially RR) ?
when you measure the supply voltage on the pcb, what does it show?
I am getting a -8.92 at -9 pad on BB.
(http://i1143.photobucket.com/albums/n625/cmsgt1997/image.jpg1.jpg)
(http://i1143.photobucket.com/albums/n625/cmsgt1997/image.jpg3.jpg)
(http://i1143.photobucket.com/albums/n625/cmsgt1997/image.jpg2.jpg)
If you've got -9v to the BB board I'm not sure how you are getting not voltage readings on the collectors. Try pulling Q1 and measure the voltage readings on the socket.
One other thing to do when measuring collector voltages for this circuit--make sure you have the balance pot turned up. It actually effects Q3 bias. Even with it all the way up, the voltage reading on Q3's collector won't be very high (perhaps less than 1 volt if you have a leaky transistor in Q3).
I think your Q1 and Q2 collector voltages should be around 3 to 4 volts. I'm just going off the fact that the setup is similar to a MkIII Tonebender, but I think that's the ballpark.
Sorry it's taken so long to respond back. I have like 4 builds that have just gone to crap and I am just really frustrated. When I get to that point I put them up and ponder on what Ive done wrong (perhaps I shouldn't be building these things is what I usually think). This seems to come in cycles. I build 5 or 6 with no problems and then a tornado hits.
The only voltage I am getting is 1.44 on the base of Q1. Nothing on 2 or 3 and I have the balance pot turned all the way up.
Double check R5. It should be a 10k resistor (brown,black,black,red,brown.). It doesn't look right to me. Try not to get overwhelmed, we've all had these rough patches.
Steve.
Its a 10K but I replaced it with another one. I reflowed all the solder points and I am still getting the 1.44 on Q1, nothing at Q2 and I am getting a 4.47 now on the collector of Q3. But now I have no bypass just a loud din when off or on. >:( :o This one is really testing my patience.
hmm following you can try:
-) have you connected your output right? i cant see if its connected to either the cap or the output pin
-) the pads from the balance pot suffered heavy soldering. i would check there if the pot pins have a connection to the circuit
otherwise: can you post a pic of your 3pdt wiring as well please?