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One-Way
Bronze Member
New Zealand
104 Posts |
 Posted - 10/02/2007 : 11:34:00
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I thought I had fixed my OD1 but after being away for a fortnight for a family funeral it has played up since I got back home.
When I stomp on it the light comes on but the overdrive takes some time maybe 20-30 seconds to kick in coming in very quietly and slowly rising in volume. If I kick it to bypass and straight away back to OD it takes less time to kick in. My leads all test out OK and I cleaned all the jack sockets before I was away.
I might try re soldering all the connections on the PCB and see if that cures the problem. Should I remove the jacks/switch and redo those as well?
I am assuming you need some fresh solder added to each connection and not just melt the existing layer? Do I need to support the wires/components connected underneath so they dont fall out when I am re soldering?
I am hoping someone may be able to pin point what the problem may possibly be?
Thanks in advance.
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/02/2007 : 12:27:24
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Hi One-Way
First of all condolences to you & your family.
And I hope you & your family are ok.
We recently had my wife's father pass away suddenly & tragically.
===
Can you send some closeup pics of both sides of the OD-1, it might help
us, to pinpoint your OD-1 problem a bit more accurately.
It could be any one of a number of faults, but I might hazard a guess as it being one of the capacitors, may have gone a bit south on you.
It could also be one or more dry joints, as you suggested.
When re-soldering, it is always best to remove the old solder, with solder wick or a hand solder vacuum pump.
Always apply fresh new 60/40 rosin cored solder, to the cleaned up joint.
Yes you will have to support the wires in some fashion.
I just use my Third Hand (all Tech's are born with an extra one)
Make a diagram of where all the wires go, or better still take some closeup pics, in case you have a wire fall off, & you can't remember where it went.
But as I said earlier, a few not blurry closeup pics will help us, help you.
It saddens me to know there is a sick OD-1 in your home, & he-she can't sing anymore.... 
Regards Dr. Bob |
Edited by - Dr. Bob on 10/02/2007 12:28:25 |
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ronster
Gold Member
Australia
645 Posts |
Posted - 10/02/2007 : 13:16:26
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Sorry about both your losses 
On a brighter note, you gotta love Dr Bob's pedal fix it service! |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/02/2007 : 14:24:20
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quote:
Originally posted by ronster
Sorry about both your losses
On a brighter note, you gotta love Dr Bob's pedal fix it service!
Hi ronster
Thanks for the vote of confidence,
I needed a little bit of that, after today's day at work...
You know that old saying?
"It's hard to soar with the Eagles, when all around you, you're surrounded by nothing but Turkey's"
Regards Dr. Bob |
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One-Way
Bronze Member
New Zealand
104 Posts |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/03/2007 : 11:25:32
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Hi
Thanks for the pics.
After much squinting & racking of my tired old brain, I have come up with the following observation.
First go to topic-thread:
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=2851&SearchTerms=od-1
Look at the last pic of Pacafeliz's two OD-1's, one of them is exactly like yours, the 8 PIN JRC4558 version.
If you look at the wires that are on the PCB.
The one numbered (5) is missing on your board,
if you look at the other pic of Pacafeliz's OD-1, it is/was a light blue wire.
I can't see where this wire is, or has fallen off to, on your pedal.
I hope this Helps One-Way.
It's the best I could do at short notice, & with the pics you sent.
On your OD-1 if you look at connection (5) it seems obvious, that there was something, that was once there & has cracked or broken off.
maybe it's one of those "Cold Solder" "Dry Solder" joints.
Maybe ChristoMephisto will spot something else that I may have missed.
Good luck with the fix Bro.
Regards Dr. Bob. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 10/03/2007 : 14:38:26
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thats too funny, i was just looking at the pics, and comparing, and noticed Dr.Bob's comment...
looks like he nailed one problem. the blue wire from your adapter jack leads to pin 5. The track that looks bad is for the bypass diode and resistor. pin4 to d4+r30 pin 5. Solder in a peice of wire to replace the track, works for me and over modded wah
Wonder if those can be jumpered like other boss pedals for using a psa adapter.
Those are good pics, but I couldn't notice anything else |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/03/2007 : 16:31:19
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quote:
Originally posted by ChristoMephisto
thats too funny, i was just looking at the pics, and comparing, and noticed Dr.Bob's comment...
looks like he nailed one problem. the blue wire from your adapter jack leads to pin 5. The track that looks bad is for the bypass diode and resistor. pin4 to d4+r30 pin 5. Solder in a piece of wire to replace the track, works for me and over modded wah
Wonder if those can be jumpered like other boss pedals for using a psa adapter.
Those are good pics, but I couldn't notice anything else
Hi Christo, One-Way & Guys
I wonder if the blue wire was modified on purpose.
It would be beneficial to measure D4 that is connected to to that bad looking track, it may actually be faulty, And the previous owner/s removed that wire to stop the 9V battery FRYING it's guts out.
I am guessing that this pedal is being run only from a 9V battery.
One-Way - can you please confirm for us, which way you run your OD-1.
IF this pedal was wired normally Christo,
you could jumper out R30 the 470 ohm resistor, & it would then function on a PSA 9V regulated adapter, if it was being run as an individual pedal.
Some Techs jumper out the Diode & the Resistor (D4 & R30),
but I like to keep the Diode still in circuit, as a double measure of protection. 
And lets be honest here,
it only drops about 0.7V DC off the main supply.
One-Way, can you read schematics? & do you need us to send you a backup of ours?
But please measure that D4 diode with a multimeter or diode tester, before you replace the blue wire back onto PCB connector (5)
Christo, can you take an educated guess, why this mod may have been done, other than what I have speculated?
Regards Dr. Bob
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Edited by - Dr. Bob on 10/03/2007 16:34:02 |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 10/03/2007 : 20:54:24
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Put on my special cone hat and gazed into my 21" monitor and found the blue wire from the adapter is wired directly to the input jack instead of five. Looks like someone tried to do a psa conversion and wired it directly to the input totally bypassing the pcb.
When you get a chance, move the blue wire at the power adapter from the input jack to pin 5 where it should be. It might be pulling the signal from the tone line
If you get no reading where that bad track is, replace it.
Let us know what you get after that.
First chance I get, I'm grabbing a OD-1 for myself
On the off note, I just finished refinishing my '65 Hagstrom's headstock, complete with water decal, and back to the original direct wiring. One volume knob and five dpdt slider switches, very old school
Can't wait to run it through my collection of pedals |
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One-Way
Bronze Member
New Zealand
104 Posts |
Posted - 10/04/2007 : 11:51:15
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Thanks for the help guys. I will try putting the blue wire back on 5 and jumper bad track. I have run the pedal on both battery and a 9 volt power supply from an old phone with the same result. It reads 11.2 volts when connected in the circuit. Is this excessive?
I have a schematic that someone kindly provided a link to though I am no expert but know what most of the components are. |
Edited by - One-Way on 10/04/2007 11:55:18 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/04/2007 : 16:48:43
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quote:
Originally posted by One-Way
Thanks for the help guys. I will try putting the blue wire back on 5 and jumper bad track. I have run the pedal on both battery and a 9 volt power supply from an old phone with the same result. It reads 11.2 volts when connected in the circuit. Is this excessive?
I have a schematic that someone kindly provided a link to though I am no expert but know what most of the components are.
Hi One-Way
Before you do anything else.....
Please check the diode with your multimeter.
Then run it on a battery first.
Checking that the battery isn't getting hot.
If all is OK then try the 12V adapter.
If you get a some or a lot of hum when using the adapter,
it's because tthe filter capacitor in it is not large enough,
if you can open it up, you can always add another, or larger cap
2200uf is a good low hum value.
Putting the pedal back to it's original state will be a big factor,
In sorting out if you have any other problems.
The plug pack off the phone..11.2V in circuit & under load should be fine.
The older Boss pedals that were designed to run on the 12V non-regulated ACA type adapters.
The Newer PSA adapters are 9V & REGULATED.
Once you get all the bugs out of your OD-1,
you can jumper out R30? the 470 ohm resistor, & it will run on the more modern PSA adapter.
BUT DO NOT THEN TRY TO RUN IT ON THE 12V adapter, after you mod it.
Check the track that looks a bit shitty, with you meter,it may have gone slightly resistive.
And as Christo said, just run a short wire link, on the back of the circuit board, between the between the those two joints.
Keep us informed as to how you go, with the back to original mods.
Hey One-Way......
Did you get this pedal from someone else?
Any idea, who or why it was messed with?
Can I ask what part of N.Z. you're from,
my close work buddy, who lives close by, is from that part of the world, In fact a few work mates are from over there.
Regards Dr. Bob
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One-Way
Bronze Member
New Zealand
104 Posts |
Posted - 10/07/2007 : 10:35:39
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Dr Bob,
We can both commiserate about our rugby teams getting knocked out of the world cup. Well maybe in another four years time?
I live in Whangarei a small city a couple of hours north of Auckland.
I bought the pedal secondhand from a music shop so dont know its history. Obviously it played up so the owner got rid of it but I am determined to get it going reliably.
The diode should only allow current flow in one direction right? |
Edited by - One-Way on 10/07/2007 10:37:22 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 10/07/2007 : 10:46:33
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quote:
Originally posted by One-Way
Dr Bob,
We can both commiserate about our rugby teams getting knocked out of the world cup. Well maybe in another four years time?
I live in Whangarei a small city a couple of hours north of Auckland.
I bought the pedal secondhand from a music shop so dont know its history. Obviously it played up so they got rid of it but I am determined to get it going reliably.
The diode should only allow current flow in one direction right?
Hi One-Way
Your assumption is correct.
what type of meter are you goint to measure it with?
Does it have a diode test function/symbol on it?
The best way to test it is with the diode test, you will got about 0.7V when it;s forward biased (conducting) & nothing in the other direction.
If you are going to test it on the ohms scale/setting, you might get some false readings, in that case lift one end of the diode so its out of circuit, & nothing else can affect it.
If it's running off the battery & adapter, you might just take the risk & connect the wire back to the correct place.
I have been thinking about what they did, it was probably to get the pedal working on the 9V PSA adapter, as the OD-1's all run off ACA 12V adapters.
But there is a much more effective way to mod it for 9V.
Once you have it all working, I will help you do the ACA to 9V PSA mod, it's just a wire link.
I'll look up Whangarei on Google Earth a bit later,
don't forget to go outside & wave to us ...
Regards Dr. Bob |
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stinkfoot
Silver Member
Sweden
181 Posts |
Posted - 10/07/2007 : 14:31:02
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Just a note about the blue wire - if you connect it straight to ground (which I assume was the way the pedal was wired, using a ground point on the input jack), there's no need to jumper the diode/resistor pair to get it working with PSA voltage. After all, that's what the jumpering method is trying to do (hook up the adapter jack's negative straight to ground). You can also (instead of soldering it to the input jack) simply move the blue wire to the connection point on the other side of the diode/resistor - in the second edition OD-1, it's connection point 4, IIRC. That does the same thing - bypassing D4 and R30, letting the pedal work with 9 volts DC.
Personally, I prefer actually taking the diode and resistor out and replacing them with jumpers, as I think it is easier to work with components rather than de- and resoldering the wire connections. On the old pedals, the wires weren't soldered through holes in the board, and getting two of them to sit tight while the solder blob cools off can be tricky. But simply soldering the blue (adapter jack negative) wire straight to ground will work just as fine.
One-Way - when the overdrive kicked in slowly, was the gain/amount of distortion constant, like someone had slowly turned up the output level control? If so, I'd take a look at Q1 (the FET that turns the distorted output on/off. If the amount of distortion changed as the pedal started making sounds, I'd look around the op-amp. Also, did the pedal work right away in bypass mode? If it too faded in during a 20-30 second "warm-up" period, while raising the amount of distortion, I'd look at the input buffer stage (Q6).
/Andreas |
Edited by - stinkfoot on 10/07/2007 14:35:48 |
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One-Way
Bronze Member
New Zealand
104 Posts |
Posted - 10/08/2007 : 10:30:13
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I pretty sure the distortion was constant like it was fading in from silent to full noise. It switched to bypass instantly and if I kicked it again straight away it would take less time to come in. It is almost like a transistor or other component that needs to charge itself up to open the circuit is not doing its job properly.
I have a digital multimeter but it doesn't have a diode tester as such only volts AC/DC, Ohms/Ohms with audible continuity tester. |
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leonard d rock
Silver Member
Philippines
301 Posts |
Posted - 01/24/2008 : 01:22:23
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hi everybody! i've experienced the same problems with my 80's mit aca od-1. i've tried some of the solutions given in this forum but the od-1 would still periodically act up again. when i read closer, somebody suggested keeping D4 in but using a jumper on R30. curiously, i couldn't find any component marked R30. so i just tried taking out D4 and replacing it with a jumper it it seems to work flawlessly for more than a week now. i hope this solves my problem and will help others. i looked really closely and there was no component marked R, let alone R30. the components were marked D, C and Q. i don't have any formal training in electronics. peace everybody!javascript:insertsmilie('')
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OD1 playing up again
