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?
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.
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!
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.
Cool!Thanks for your help and knowledge!
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
Quote from: zombiwoof on November 17, 2012, 12:30:41 PM
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.
Quote from: zombiwoof on November 17, 2012, 12:30:41 PM
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
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.
Quote from: armdnrdy on November 29, 2012, 09:03:10 PM
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!
> 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.