BBE Two-Timer Delay Problems

[soupbone]

I'm  trying  to  fix  a  BBE  Two-Timer  Delay  that  a  friend  gave  me.The  only  thing  that  i  can  find  out  for  sure  is  the  transistor  U5(CJ 78L05  011) and  the  cap  right  next  to  it  C36(Looks  like  a  small  tanatlum  cap.Says  104 0.1uf?)but  it's  not  polarized.Monothlythic  maybe?Both  of  them  when  i  plug  in  my  1 Spot  adapter  they  get  real  hot.It's  only  those  2.Can't  figure  out  what  be  causing  this?

[armdnrdy]

I haven't looked at the schematic if it's available but I can offer a bit of help. U5, the 78L05 is a positive 5 volt, voltage regulator. The non polarized cap you described as being marked 104 sounds like a .1uf monolithic ceramic capacitor. Non polarized tantalum caps are made but are expensive and uncommon. Tants are usually marked with a uf rating rather than the code that is generally associated with ceramic caps.

Check the output of the regulator for 5 volts.

[soupbone]

Cool!A  couple  of  quick  questions; I've  got  a  bunch  of  .1uf  metal  film  caps.Can  i  use  one  of  those  to  replace  the  monloythic  cap?)When  you  said  to  check  the  transistor  voltage,Do  you  mean  to  take  my  MM  and  test  one  of  the  legs  of  the  tranny  to  see  if  it  reads  5  volts?Thanks  for  your  help!

[armdnrdy]

Check the output of the voltage regulator pin 1 to ground. Pin 1 is the one on the left looking at the flat side of the regulator.

As to your second question, your film cap will probably work, but my thought is, by your description it seems to be located in the power section, and a monolithic was chosen for a specific reason. Monolithics are better for high frequency filtering and have lower ESR than film caps. In some designs you will see a larger electrolytic and a smaller value monolithic in parallel in the power section. The monolithic covers the electrolytics shortcomings.

[soupbone]

Cool!Thanks  for  your  help  and  knowledge!

[zombiwoof]

If you can't get it sorted out, consider sending it to BBE support to fix it.  They fixed a bad pot on a USED BBE pedal I bought on Ebay, for free, including shipping it back to me.  Great support at BBE IMO.

Al

[soupbone]

If you can't get it sorted out, consider sending it to BBE support to fix it.  They fixed a bad pot on a USED BBE pedal I bought on Ebay, for free, including shipping it back to me.  Great support at BBE IMO.

Al

Cool.Yeah,If i can't get it going ,I'll definately give them a call.

[soupbone]

If you can't get it sorted out, consider sending it to BBE support to fix it.  They fixed a bad pot on a USED BBE pedal I bought on Ebay, for free, including shipping it back to me.  Great support at BBE IMO.

Al

I got a hold of BBE.They sent me the schematic.Here's the link; http://s1143.beta.photobucket.com/user/soupbone71/library/  The guy i talked to said it could be the filter caps(I don't which ones they are?)or a zener diode.From looking at the schematic Al,Can you maybe tell me which ones they are?Thanks in advance,-soup

[armdnrdy]

Did you ever take a measurement of the output of U5? (7805 voltage regulator)

I think that would be very telling!

Okay, the BBE guy told you it might be the zener diode or filter caps.

There's no zener diode in this build so.....he must of meant D3 1N4002 the protection diode.
The filter caps are C33 1000uf (real big polarized cap) C36 .1uf you know that one. The one that's heating up.

Once again, First I would meter the output of the regulator to be sure everythings good downstream of the problem area. Next, I would check the diode. Unsolder and lift one side of the diode before testing with a meter. If you don't the electrons might find a path completing the circuit to your meter through other components. Result....faulty reading.

Do the same with the filter caps. Be careful not to overheat pads and traces when unsoldering the components so you don't lift them.

Let me know how it goes.

[soupbone]

Did you ever take a measurement of the output of U5? (7805 voltage regulator)

I think that would be very telling!

Okay, the BBE guy told you it might be the zener diode or filter caps.

There's no zener diode in this build so.....he must of meant D3 1N4002 the protection diode.
The filter caps are C33 1000uf (real big polarized cap) C36 .1uf you know that one. The one that's heating up.

Once again, First I would meter the output of the regulator to be sure everythings good downstream of the problem area. Next, I would check the diode. Unsolder and lift one side of the diode before testing with a meter. If you don't the electrons might find a path completing the circuit to your meter through other components. Result....faulty reading.

Do the same with the filter caps. Be careful not to overheat pads and traces when unsoldering the components so you don't lift them.

Let me know how it goes.

Hey Larry.I'm getting ready to measure the output of U5.After i find out I'll report back.Thanks!

[PRR]

> they get real hot

If it has been violently abused through the power jack, or is old (or cheap), then replace D3 C33 U5 C34 and maybe C36 and C37.