Boss v wah . surface mounted diode ?

[gogul808]

Hi , recently I was given a boss v wah pedal that did`nt work .After taking it apart the only thing I can see wrong with it, is a surface mounted diode that has burnt out big time styley  
After the most stupidest email I have have ever received from roland/boss about trying to identify the diode in question ,I asked an electronics guy on a youtube channel I am subcribed to if he knew what it was exactly . He told me "The part number identifies the diode as a 40V 1A Schottky Power Rectifier."  I know very little about electronics but can solder surface mounted doodads with ease . The diode has PJ27 SS14 on it . Is what he told me correct ? as I thought 40 volts sounded a little high , but like I said I know less than nothing about this stuff.Any help/clarification would be mucho appreciated as I don`t like guitar pedals dieing ! ^^

oh  & yes here`s a picture of it


and heres a pic of the mainboard for you curious types since there is very little around the web on the pedal

[g_u_e_s_t]

yes, that looks correct.  look for ss14 diode
http://www.mouser.com/Search/Refine.aspx?Keyword=ss14

[gogul808]

cool , ty for the reply better to be safe than sorry , I don`t want to damage it anymore than it already is

[gogul808]

yep I got a rectifying diode (off ebay though where the postage prices were`nt ridiculous ! 12 quid postage for a teeny diode? lol not for me ) and it worked off the bat first time
another pedal saved from the rubbish dump
free broken pedal ,5 quid diode , nice pedal !

[gogul808]

With excellent timing as I have just got back from morocco today I received this personal message on this site

Hi dude:
I saw your post about how you fixed the burnt diode on your V-Wah, and something similar happened to me:
I bought the pedal to a man who told me it wasn't working, and when I opened it, I found this:



IC9 and Q10 are blown, so if you could tell me what do the components say on the top or send me a pic, I would be SO glad 

I would thank you any suggestion about this project 

Regards 

(PD: Sorry for the bad english, I'm from Mexico xD)

here is the picture as I promised my mexican friend


on Q10 it says 5fks 7606 & on  IC9 seems to say BJSW (hopefully somebody from this site will be able to tell you what they are which will help you in finding the little buggers:)



as to what they are As of right now I have no idea, but thats why I posted your message contents publicly to get help identifying what  Ic9 and Q10 actually are as there are some very knowledgable people on this website .I think given the severity of the burning on yours paquechee maybe some Gentle cleaning up if possible of the affected areas would be needed before putting the new parts when you`ve found out what they are that is

as i said in my message to you earlier your english is very good and infinately better than my grasp of spanish  and i`m sure the grammar nazis will not show their faces on such a chilled website
anyhoo hope this helps for the day buddy as I am going to trawl through my holiday pics before my bed adios amigo 

[paquechee]

Thank you so much man!

I don't know what the letters mean, but I'm going to tell a friend who really knows about pedals and electronics (in fact he is going to help me to repair if I find the pieces  ) ) if he knows what that means. If so, I'm going to post it here 

I think your idea is great! We should make a kind of list of the components that tend to get damaged, so everyone could have a reference if their pedals stop working

So I'm gonna try to get as much info about pieces as I can and tell you, as well as what happened to my wah 

Saludos   

[gogul808]

no probs bud , glad to help .Yeah i think if  possible, this threads name should be changed to the Boss v wah thread.

I did notice some of the components on your pedals circuit board seem to be different than the ones on mine .For instance the rectifying diode in your d5 position seems to have pj40 ss12 on it , on mine is a pj27 ss14 .Also the capacitors have different values written on the tops of em .

I wonder why ? maybe your pedal was built before mine or vice versa .
Given the fact there seems to be a tendency for parts to frazzle themselves , I would say it seems prudent to use batteries only to power it .

just found this link   http://en.wikipedia.org/wiki/Electronic_symbol

which is handy

[g_u_e_s_t]

q10 looks like an IRF7606, which is a p-channel mosfet.  ic9 is most likely a dc/dc buck regulator, set to output a fixed voltage.  the lettering on top is probably just a part code, and not the real part number.  if you can figure out the input/output voltages on it, you an just source a replacement.  it looks like pin1 is enable, pin2 ground, pin3 Vout, pin4 switch, pin5 Vin.  pin5 and pin1 are tied together, so they could be swapped.  take a look at the FT440, its similar, but not quite right.  youll want an SOT23-5 package.

[paquechee]

Yeah, thats wht I thought, but IRF7606 is unavailible here in Mexico, so I'm gonna try to find a substitute 

About the regulator, I will have to take your info to my friend, and may be he knows how we can solve it 

Meanwhile, I'll try to get info about the components in question from Roland/Boss 

[gogul808]

good luck buddy , as I asked boss/roland what the diode was exactly that burnt out on mine .I got a reply suggesting i send the pedal to japan to be fixed by them for the VERY reasonable fee of 140 quid ! lol The sheer idiocy of it lol , i could buy two of em new off ebay for that .Luckily i found someone helpful on youtube and had a happy ending .(no not in the "massage" parlour sense btw  )

[batpuppy]

Hi Paquechee,

Apologies for the resurrection of this post.  You posted about your Boss V-Wah (Burnt out IC9 and Q10).  I have the same issue with IC9 and there are no guarantees that Q10 is functioning.  I am really struggling to find the identity of IC9 on the V-Wah board and although Q10 was likely resolved in the forum, I don't want to take a chance with Q10 either.  Did you or your electronics buddy resolve the issues and if so, I don't suppose you have the part names for either or both, please?

Thanks for your time,

batpuppy

[batpuppy]

Anyone, please?

[eagleaudio]

As it was mentioned this U9 is a step-up converter controller in SOT-23-5. You have to search for controllers in this package and match them with the circuit. You may also check what voltage was delivered by the controller and find simmilar one. There are many controllers that could possibly match; for example this one: http://www.onsemi.com/PowerSolutions/product.do?id=NCP1402 (but bear in mind that I haven't check the pinouts).

Eagleaudio

[batpuppy]

As it was mentioned this U9 is a step-up converter controller in SOT-23-5. You have to search for controllers in this package and match them with the circuit. You may also check what voltage was delivered by the controller and find simmilar one. There are many controllers that could possibly match; for example this one: http://www.onsemi.com/PowerSolutions/product.do?id=NCP1402 (but bear in mind that I haven't check the pinouts).

Eagleaudio

Thanks Eagleaudio.

Needed my hand holding a bit with this one.  Analogue ICs/passives only, no problem.  Digital on the board scares me a little.  Will look to check the voltages.

Best wishes,

Battus