r151 esistor starts burning after powering on !
checked all 20 times !
Somebody any other sugestions
r 151 accent resistor burns
As stated in the thread VCA accent troubles, we are 2 people to have this same problem, and at least me without any other unfindable mistake (yes only another one but I know why).
I also checked many times a lot of things, so much that with all the movements, I broke the "Cable 10Pos" linking both PCBs! I checked every component's place and way, resistors values, and transistor's proper functioning of the accent section.
I also checked many times a lot of things, so much that with all the movements, I broke the "Cable 10Pos" linking both PCBs! I checked every component's place and way, resistors values, and transistor's proper functioning of the accent section.
Dear Diyer,
R151 burned because you get a short cut between ground and +15v psu rail.
C34, Q27 or the 4011 could be the problem.
Best regards,
e-licktronic
R151 burned because you get a short cut between ground and +15v psu rail.
C34, Q27 or the 4011 could be the problem.
Best regards,
e-licktronic
Best regards,
e-licktronic
e-licktronic
Hello franzkleid,
I had same problem on 4th batch kit.
Please try unbuffered 4011UB.
I solved R151 problem by it.
cheers
I had same problem on 4th batch kit.
Please try unbuffered 4011UB.
I solved R151 problem by it.
cheers
Thank you!
The batch before the 4th did have a different 4011 than BE?
The batch before the 4th did have a different 4011 than BE?
wow is that really the issue? My local electronics retailers don't seem to differentiate, just listing "4011" without any suffix. I guess I could go in-person or call to verify the buffered vs unbuffered versions...keen wrote:Hello franzkleid,
I had same problem on 4th batch kit.
Please try unbuffered 4011UB.
I solved R151 problem by it.
cheers
EDIT: I just checked the TR-808 service manual and as far as I can tell they used 4011B type NAND gates. So maybe that's not the problem?
Attached screenshot from the service manual:
Hello.
Sorry, I'm not sure why UB version solved it.
I have 2 kits of 4th batch. Both kits had same problem. And solved it with 4011UB.
BTW, 4011UB is used for 9090 too.
regards,
Sorry, I'm not sure why UB version solved it.
I have 2 kits of 4th batch. Both kits had same problem. And solved it with 4011UB.
BTW, 4011UB is used for 9090 too.
regards,
Replace your 4011. I replaced mine with a 4011BE and it's rocking now!
I also have a few yocto kits so I tried with the 4011BE of another kit (not built yet), and again the same problem!
By the sound of it there may be some issues with the 4011 used seeing as a fewguys have had issues with them. Pick yourself up a new one from an electronics shop and see how you go.