Ibanez FL-301 trouble

angelodp · January 02, 2011, 04:46:43 PM

Hi, new to this forum and could use some help fixing an old Ibanez FL-301 Flanger. The board inside says Maxon MP FL0401A. I do believe that I inadvertently put a mismatched power supply on the unit and it does not light up anymore. I am looking to trouble shoot the pedal, any help would be greatly appreciated.

I think it just might be the Polarity protection diode? How do I test for that... better yet find it.

"It's quite common for a polarity protection diode to short. Be suspicious of these if you have a power problem."

best A

Bullet79 · January 02, 2011, 07:58:57 PM

i'v build a couple FL-301's Flanger... the diode is one thing,.. but i'm sure you got the 12v regulator fried.. and the p.diode should be close...

angelodp · January 02, 2011, 08:34:36 PM

Ok, thanks. Can you tell me how to check for that diode and what it looks like ( its location )... any additional diagnostic help is appreciated.

A

Govmnt_Lacky · January 02, 2011, 09:50:30 PM

A good picture of the circuit board component side or a link to the schematic would do wonders!

EDIT: Just looked up the schem. Looks like the protection diode is D104 and the regulator is IC106. Here is a link for your board

http://sites.google.com/site/matthewkloiber/schematic.GIF

angelodp · January 02, 2011, 11:18:47 PM

I have taken reading to ground of just about every node, except diode 102 ( which reads .02vdc ), reads 17+ volts. I have never done any trouble shooting on a pedal so I do not know if this is on the right track.

angelodp · January 03, 2011, 12:32:33 AM

All nodes except the spot in red in the middle of the board ( solder side ) read 9v.... the red arrow juncture is at .02v

Govmnt_Lacky · January 03, 2011, 08:23:45 AM

Quote from: angelodp on January 02, 2011, 11:18:47 PM
I have taken reading to ground of just about every node, except diode 102 ( which reads .02vdc ), reads 17+ volts. I have never done any trouble shooting on a pedal so I do not know if this is on the right track.

Angelodp.... I don't quite understand what you are trying to say here however, what you should do since you believe you installed a wrong power supply is to trace the power from the board input (DC jack) and look for a diode that goes from the power path (striped side) to ground (un-striped side). Check that diode and ensure that you have input power on the striped side and ground on the un-striped side. If you do not have these readings then, that power protection diode is bad.

Next, check your voltages and ground at the 12V power regulator. That is the part that looks like a transistor that is closest to your DC jack (in your picture) that is labeled 78L12. With power applied, you SHOULD read DC input power on one of the outside legs, ground on the middle leg, and 12VDC on the other outside leg. If you read anything else then the 12VDC regulator is bad.

After that, I suggest you follow the "What to do when it doesn't work: Debugging" thread. Here is a link:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Good Luck and be sure to post back if you find the problem so others can learn.

angelodp · January 03, 2011, 11:49:45 AM

Hi, can you define striped and unstriped side please. Are the diodes the little cans with the chopped off edge.

Govmnt_Lacky · January 03, 2011, 11:53:51 AM

Quote from: angelodp on January 03, 2011, 11:49:45 AM
Hi, can you define striped and unstriped side please. Are the diodes the little cans with the chopped off edge.

I can only help you SO much dude!

You need to learn the basics first. This is a DIY site after all. I would suggest you use Google to find out the shape, sizes, differences etc. between diodes, capacitors, transistors, resistors, etc.

Just Google diode and it will show you the way....... along with many other facts

Not trying to sound like a jack-hole but if you do not know what the components even look like..... then ALL OF US on here will have an incredibly HARD TIME helping you from here on out.

angelodp · January 03, 2011, 11:56:52 AM

I know what caps and resistors look like, but I am not familiar with the type of diodes used in these pedals. could you simply point one out please. I assume the little cans with the chopped off tops?

Govmnt_Lacky · January 03, 2011, 12:07:34 PM

In your pictures above... the top picture of the component side. Look just to the left of the black arrow tip. You notice a small ORANGE component? It is mounted vertically and it has a small black stripe on one end of it. That is one of the diodes that are in the circuit.

angelodp · January 03, 2011, 12:10:55 PM

Ok, sorry, my eyes are not what they used to be. I see that now. OK ... I will go back to your recommendations on reading voltages and report back.

angelodp · January 03, 2011, 07:11:29 PM

Checked all diodes and they are fine. The 12v power regulator however does not read according to your notes. I get 18v on all three pins. Looks like its gone south, would that be correct.

"Next, check your voltages and ground at the 12V power regulator. That is the part that looks like a transistor that is closest to your DC jack (in your picture) that is labeled 78L12. With power applied, you SHOULD read DC input power on one of the outside legs, ground on the middle leg, and 12VDC on the other outside leg. If you read anything else then the 12VDC regulator is bad."

twabelljr · January 03, 2011, 07:59:25 PM

If you are reading 18V on the center pin then it seems you have a ground problem. Where are you touching or hooking the black lead of your meter when taking these measurements?

angelodp · January 03, 2011, 08:03:29 PM

I have the black meter lead on the black wire of the input jack.

twabelljr · January 03, 2011, 08:05:32 PM

Do you have continuity from the jack to the bottom of pad 14?

EDIT: Print that schematic Govmnt_Lacky found for you. The center pin of IC106 should have continuity to ground (anything with the diagonal hashmarks should be grounded). Do your continuity tests WITHOUT power applied to the board.

angelodp · January 03, 2011, 08:34:04 PM

You mean the power jack... yes. Yes I have the schematic. The center pin of 106 does not show continuity to ground.

twabelljr · January 03, 2011, 08:50:19 PM

QuoteThe 12v power regulator however does not read according to your notes. I get 18v on all three pins.

I think you need to check the board grounds. If you read 18v on the center pin of the regulator then it is not grounded. Something blew or burnt. Trace from the jack to where the black wire connects to pad 14, if good then follow the trace from pad 14 to the regulator common. (center pin). That's about all I got. Hope it is of some help. Good Luck!!

Govmnt_Lacky · January 03, 2011, 10:36:47 PM

Quote from: angelodp on January 03, 2011, 08:34:04 PM
You mean the power jack... yes. Yes I have the schematic. The center pin of 106 does not show continuity to ground.

The center pin of the 12V regulator (IC106) SHOULD READ CONTINUITY TO GROUND! If it does not, then that is a problem that needs to be fixed BEFORE moving on. DO NOT continue on without finding and fixing this problem. If you do you will just end up chasing your tail.

I would recommend checking for a bad solder joint on the center pin of the regulator to the circuit board. Next, you should check the ENTIRE board run from the center pin of the regulator ALL THE WAY back to where it connects to the ground input. If that ALL checks out, then replace the 12V regulator.

Instinct tells me that you have killed the regulator with the suspected wrong power supply that you say you plugged in BUT, you should take the time and investigate the circuit BEFORE jumping to replacing the part.

Good Luck and report back with what you find.

angelodp · January 03, 2011, 10:39:16 PM

Will do, is that part readily available. Small Bear?

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Ibanez FL-301 trouble