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larry greenwood
Copper Member
Malaysia
42 Posts |
 Posted - 01/27/2010 : 11:57:00
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hello
i just bought a wh-1 from ebay last month
the pedal has arrived on my doorstep last friday
it was a quiet deal though
the seller sent me a harman pro 120v input adapter
i didn't noticed about this, i thought it used 240v input adapter just like here
after switch on the pedal
the adapter start to burn
i quickly pull the adapter because worrying anything happen to the pedal
after that i went to a local guitar store at my place
and send the pedal for a check
the next day the technician told me that the transister on whammy's circuit board kinda shot out because of adapter that seller gave me
so i'm hoping can someone help me with this
what model of transister that wh-1 use?
and is it easy to find model?
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/27/2010 : 14:28:08
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Hi larry greenwood
Welcome to the forum from Australia.
Sorry to hear about your problem,
using the incorrect power supply for your region of the world.
It's very important to always double check the voltage requirements
or your equipment before plugging it in.
You might have to upload some pictures.
For us to see if we can help you.
The 240VAC into the 120VAC power supply should have only fried the plug pack.
Unless there was a monetary spike on the secondary of the transformer?
Is the Harman Pro 120v.
a switching (SMPS) type power supply or a transformer (linear) type?
I'm not sure of any of us here have the Schematics for the WH-1.
Regards Dr. Bob  |
Edited by - Dr. Bob on 01/27/2010 14:29:46 |
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larry greenwood
Copper Member
Malaysia
42 Posts |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 01/27/2010 : 23:28:28
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Hi
These are not transistors but 3-terminal positive (LM340T5) and negative (7908CT) voltage regulators. You should be able to find replacements very easily. |
Edited by - cctsim on 01/27/2010 23:31:55 |
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/28/2010 : 00:15:00
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okay
thank you
so what i have to do is find the parts and replace it with the old one?
should i check on other components? |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 01/28/2010 : 00:41:45
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| If you have a volt meter I would check first if they are still working before trying to replace them. |
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/28/2010 : 00:50:46
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i dont know weather it still working perfectly or not
but as i switch the pedal on, the chip starting to heating up
i realize this problem when holding the wh-1 body
should i change it?
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nosi0
Gold Member
Netherlands
511 Posts |
Posted - 01/28/2010 : 12:18:12
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| the 7805 is meant to get hot as is the 7809 so that it heats up should actually be a good sign. What are you using to power it at the moment? |
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/29/2010 : 07:52:52
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okay nosi0 
but did you said it a good sign?
are you telling me there's nothing wrong with my pedal?
you said 7805, is that the one inside the circuit or the one that are glued to pedal's body?
because the pedal is heating up
i mean at the power input area
so i thought it might need a repair
and i'm using the wh4 power supply to power my pedal
is it okay?
the adapter input is 240v
and output is 9v/1300mA
i'm not really sure about other specs
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/30/2010 : 08:35:14
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did anyone have this answer
i'm trying to fix the pedal
so did i need to find a vintage electronic part to replace the old one?
and if i use a new part will it effects my pedal's tone?
really appreciate any kindness
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/30/2010 : 08:44:40
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quote:
Originally posted by cctsim
If you have a volt meter I would check first if they are still working before trying to replace them.
should i find a vintage electronic part or the new one?
is it normal that the voltage regulators is heating up when they're working? |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/31/2010 : 00:11:34
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Hi larry greenwood
Thanks for your PM requesting a helping hand.
As you may be aware, it can be very difficult (sometimes near impossible),
to do remote diagnostics & repair of electronic gear.
First of all, you are going to have to tell us what basic test gear you own or have access to.
A Multimeter would be a good start.
You will also have to tell us what level of skill you have in electronics.
You will need the multimeter, and some basic soldering/desoldering equipment.
Staring at the most basic point.
The (generic I assume) power supply you are now using in place of the 120V one you blew up.
Tell us what no-load voltage you are getting out of it?
is it regulated, is it of the same voltage & current rating as the original?
And what was the specified output voltage on the original supply that blew up - read the label on the unit.
The regulators can get hot, depending on how much current is being drawn from them & what input voltage (from the PWR supply) is going into them.
Consider if you run 9VDC into a 5V regulator, then it has to dissipate
the extra 4V from the supply as heat 9V-5V = 4V.
next, if the input supply is 12VDC then it's 12-5 = 7V that the regulator now has to dissipate.
Do you see the situation, there is a lot more heat dissipated in the second case.
If you have a multimeter - you might want to set it to (Diode Test) & test the two black rectifier (possibly protection) diodes right next to the two regulators.
Smell all around the circuit board, can you smell any burned smells?
It's unlikely that you damaged the 5V & negative 9V regulators, they are very robust.
Changing these for any other good quality brands will not affect the sound.
BTW, I was just wondering, after seeing the two black diodes.
IS the original power supply.
DC out or
AC out, that would make a lot of difference.
The more you help us, possibly the more we can help you.
If you don;'t have access to any test or soldering equipment,
the situation is going to be very difficult for us to help you diagnose & repair.
Have you considered that they may be some other Whammy related forums
elsewhere on the web.
You might ask them if they have a Schematic they might sent to you?
I belive Ollie has one of the Whammy family.
Ollie can you tell us/me what the specs. of the power supply on your one is?
AC out or DC out? As well.
I leave it here for now.
Regards Dr. Bob
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Edited by - Dr. Bob on 01/31/2010 00:14:10 |
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nosi0
Gold Member
Netherlands
511 Posts |
Posted - 01/31/2010 : 00:13:06
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| Voltage regulators are meant to heat up so that is fine, as long as you cant fry an egg on it! I wouldnt replace what isnt broken, though the voltage regulators shouldnt have effect on the tone. |
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/31/2010 : 20:17:45
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quote:
Originally posted by Dr. Bob
Hi larry greenwood
Thanks for your PM requesting a helping hand.
As you may be aware, it can be very difficult (sometimes near impossible),
to do remote diagnostics & repair of electronic gear.
First of all, you are going to have to tell us what basic test gear you own or have access to.
A Multimeter would be a good start.
You will also have to tell us what level of skill you have in electronics.
You will need the multimeter, and some basic soldering/desoldering equipment.
Staring at the most basic point.
The (generic I assume) power supply you are now using in place of the 120V one you blew up.
Tell us what no-load voltage you are getting out of it?
is it regulated, is it of the same voltage & current rating as the original?
And what was the specified output voltage on the original supply that blew up - read the label on the unit.
The regulators can get hot, depending on how much current is being drawn from them & what input voltage (from the PWR supply) is going into them.
Consider if you run 9VDC into a 5V regulator, then it has to dissipate
the extra 4V from the supply as heat 9V-5V = 4V.
next, if the input supply is 12VDC then it's 12-5 = 7V that the regulator now has to dissipate.
Do you see the situation, there is a lot more heat dissipated in the second case.
If you have a multimeter - you might want to set it to (Diode Test) & test the two black rectifier (possibly protection) diodes right next to the two regulators.
Smell all around the circuit board, can you smell any burned smells?
It's unlikely that you damaged the 5V & negative 9V regulators, they are very robust.
Changing these for any other good quality brands will not affect the sound.
BTW, I was just wondering, after seeing the two black diodes.
IS the original power supply.
DC out or
AC out, that would make a lot of difference.
The more you help us, possibly the more we can help you.
If you don;'t have access to any test or soldering equipment,
the situation is going to be very difficult for us to help you diagnose & repair.
Have you considered that they may be some other Whammy related forums
elsewhere on the web.
You might ask them if they have a Schematic they might sent to you?
I belive Ollie has one of the Whammy family.
Ollie can you tell us/me what the specs. of the power supply on your one is?
AC out or DC out? As well.
I leave it here for now.
Regards Dr. Bob
i'll do the check again tomorrow
if i need your help i'll pm you
is it okay?
thank anyway dr bob
no, i should call you dr bob the master of pedal
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larry greenwood
Copper Member
Malaysia
42 Posts |
Posted - 01/31/2010 : 20:21:45
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quote:
Originally posted by nosi0
Voltage regulators are meant to heat up so that is fine, as long as you cant fry an egg on it! I wouldnt replace what isnt broken, though the voltage regulators shouldnt have effect on the tone.
thanks nosi0 for some informative information
i'll try to check with my multimeter to see the main problem
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/01/2010 : 10:19:37
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Hi larry greenwood
quote:
i'll do the check again tomorrow
if i need your help i'll pm you
is it okay?
thank anyway dr bob
no, i should call you dr bob the master of pedal
No do not PM me.
If we both post here on the forum,
we all get to learn from each other.
In a PM that's pretty much where it will stay, & that's not fair to the other members.
Besides, & not counting the number of PM's that I get daily, & have to try & respond to,
Some days all the PM'S are just overwhelming.
It's always preferable to post here on the forum.
We don't bite, & you have many more chances of the other Tech guys trying to help you out.
Regards Dr. Bob |
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Topic |
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wh-1, really need a pro advice
