I have an opportunity to buy a dead Line 6 DL4 for $125. That's about half what they go for normally, but it's not showing any signs of life with fresh batteries. I didn't have an AC adaptor to test with.
Has anyone here had any chance to work on one of these? Are there any known issues with the power supply that might make purchasing it worth the risk?
After fixing the Whammy pedal last week, I'm feeling a little overconfident. :)
Hmm.... They've now got three of these things that suffer from the same issue.
It makes me wonder if an attempt was made to power them up with the wrong adapter and that adapter was used on all of them. The good folks at line 6 replied to an email I sent asking if those pedals handled their own power rectifying and filtering and they said yes. If you can, check to see if the internal voltage regulator is shot. If that's the case, it's an easy fix. Beyond that, I can't think of anything else.
B.
does any of them work with batteries?..
I used to work as repairman for the scandinavian Line-6 distrubitures, so I think I can help...due to signed non-disclosure agreements, I cant send you copies of the schematics, but i can guide you through...
..so follow me now...
...first thing to do. Plug a monoplug into the mono input, press footswitches 1 and 4 down and apply power. dont let go of the switches for at least 5 seconds. if nothing happens, its time to open up.
from the AC-in, power goes throu a 3,6v Zener ( D16 ) then on through D11. the 3,6v zener are known to fail, but doesnt affect battery operation.
after D11, power meets up with the battery in... next comes U14, a little 8-pin ( SMD ) MAX887. this one takes things down to 3,3volts ( mesure pin7/ signalground ). if you have 3,3volt on pin7, go on to U20.
U20 is a MAX660 wich is a voltage doubler. check the DC voltage on pin1 ( or 8, they are tied together ). if you have 6,6volt here, next in line is a tiny thing called LM3480 ( U21) this one will even out things for the digital domain to 5 Volt...if you havnt found fault yet, and reset doesnt work..dont bother...
..so the most likely suspects are
1: 3,6v Zener ( D16 )
2: MAX887 ( U14 )
3: MAX660 ( U20 )
4: LM3480 ( U21 )
hope this help...
johan
Johan is my new best friend online! :icon_lol:
I own a DL4 and that info may come in handy someday, although I hope I never need it! Thanks.
Say Bellyflop, do you plan to but more than one?
B.
Thanks Johan. No, none of them worked with batteries. I plugged a cable in the mono input and pushed the buttons individually. Nothing.
Is it still possible they might come to life by with the reset procedure? Do I need to hold down buttons 1 and 4 as I put the batteries in? If so, I'll need to take someone with me. :)
BDuguay, no I only plan to buy one. The SMD chips are a bit of a roadblock, though. My wife could replace them with her eyes closed, but then I have to tell her I bought it. ;D
Quote from: bellyflop on January 24, 2006, 04:56:42 PM
Thanks Johan. No, none of them worked with batteries. I plugged a cable in the mono input and pushed the buttons individually. Nothing.
Is it still possible they might come to life by with the reset procedure? Do I need to hold down buttons 1 and 4 as I put the batteries in? If so, I'll need to take someone with me. :)
BDuguay, no I only plan to buy one. The SMD chips are a bit of a roadblock, though. My wife could replace them with her eyes closed, but then I have to tell her I bought it. ;D
try the reset either way..
if using batteries, power up by simply plugging in with the footswitches pushed down.. :)
johan
Quote from: Johan on January 25, 2006, 01:21:23 AM
try the reset either way..
if using batteries, power up by simply plugging in with the footswitches pushed down.. :)
Oh sure, it sounds obvious
now. :D Will do. I'll report my findings back here.
Johan,
Any ideas on where to go if I get 5 V on the upper right-hand side of LM3480 ( U21 )? Just curious. I seem to be getting the right voltages everywhere else, it just doesn't turn on. ???
Help!?
-Joe
Quote from: bellyflop on January 25, 2006, 01:41:51 AM
Quote from: Johan on January 25, 2006, 01:21:23 AM
try the reset either way..
if using batteries, power up by simply plugging in with the footswitches pushed down.. :)
Oh sure, it sounds obvious now. :D Will do. I'll report my findings back here.
I just realized I didn't report back. I tried all the delays a couple of days later. I couldn't get any response with the reset procedure. I decided to let it be someone else's opportunity. Thanks for trying, Johan.
i think you did the right thing, i just bought a used dl-4 for 150 at a local music pawnshop... the thing came with an adaptor and both adaptor and unit are in excellent shape. ill keep an eye out for another one, and let you know about it if you really want one?
i know this was the one pedal i just had to have... and findingit for 150 was like yeah! even on ebay they go from 180-250.
I'm really hoping to fix the one I have, though if I can't... one for $150 with adapter is a pretty good deal!
DL4 – A fix for Dead-After-a-Year problems.
Strange device... Lots of people complaining about a failure that seems typical and predictable to all the Line-6 products based on this circuit board, the DL4, MM4 and FM4. Lets see what's going on.
First we open up. Man those knobs are hard to get hold of to pull off the shafts. I used good-sized slip-joint pliers set wide and went for the square ends of the grip hoping to leave a less perceivable mark and it went well. The 4 little white nylon spacers hidden in the foot button springs will all fall out when you finally separate the circuit board from the case, so watch for them. These spacers can be fine tuned in length if you want to make sure that your stomp button bottoms-out before placing full pressure on the tact-switch under it. Another note about these tact-switches; they are available in three flavors, practically free, dirt-cheep and cheep! The ones used in production are practically free. The difference between the three is, how much pressure they will take during cycle tests before failing. I replace these in lots of designs from many different stomp makers. They are a common switch and fail frequently. Replace them with the good ones (at .30 cents each from Digi-Key SW412-ND) with yellow buttons marking them rated at 260grams cycle tested. These will last. Ok, back to the failed circuit board.......
We have a digital circuit based on standard D/A, A/D stuff. Don't expect problems with most of the real workings. Good Jacks and user interface hardware. This looks like a power supply implementation problem right up front and center to these types of complaints. I did the reset operation and checks outlined by Johan who had some time in working for Line-6.
Basic voltage checks at the usual front-end points and at the;
MAX887 (U14) Dc-Dc-converter pin8 (chip input) = 6+v (batteries), Pin7 (output) = 3.3v (expected) (got nothing on mine, device dead).
MAX660 (U20) voltage-Inverter/doubler Pin8 (output) = 6.6v (expected) (Ok after removing the dead MAX887 and substituting good 3.8 (3.3) volts at its pin7.
LM3480 (U21) 5v-digital IC power regulation, (so far things tell me our circuit will probably stand up to 6.5 volts anywhere on the board without frying anything). Volt test for 5V ok here with the preceding MAX 887 bypass for good 3.8 (3.3) volts.
OK... an important note here. I actually needed to push at least 3.8 volts DC onto (the now un-populated) pin7 of (U14) to get the DL4 to light up again and to get the other test points working. I don't know if there is a small load somewhere, or if things just got old and tired after a year but even if the MAX887 was working, this stomp would still be dark without a little more juice driving it. This may be why so many DL4's out there are determined dead after passing the "factory" volt tests. Maybe things are running a little too close to tolerance. Try the following fix since yours is dead anyway. We are only going to remove a few things from the board and push it another half-volt harder, so you won't even need a run to the store to try this.
One more problem, keep reading.
If you take the circuit board out of it's case, remove the MAX887 (U14) and simply power pin7 with about 4 volts DC, the lights (hopefully) will come on, but all blinking because it thinks the batteries are low and it has not finished the boot-up to full functioning (yet). We will need to satisfy this issue during boot-up.
Now I am planning at this point to power this fix with a new (4.5v DC) wall transformer from Radio Shack, skipping the original AC to DC rectification part and keeping the battery option working too (although with only three of the batteries instead of four, (4.5V)). All I need to convert the power jack input over to use a DC adapter is to remove the Zener Diode (D14) which is trying to clamp my volts down to 3.6 volts (which I have already determined is not enough to drive this stomp any longer and is known to fail in this stomp with a 9v adapter against it anyway). I will leave the other two rectifier diodes in. They will not affect the conversion.
Poking around for volts while going through a couple of power-ups and downs will show that the Cap (C40) needs to rise above 5.6 volts before the low battery trigger will stay off and we need this to happen immediately on power-up to avoid a brain lock. If batteries are in the device, this cap remains charged all the time and is ready. Without batteries it charges instantly when the adapter is plugged in. This is a 1000uf cap and I found I could get enough volts from the MAX660 voltage doubling cap (C59) to work, but it charges (C40) too slowly to prevent a boot lock up. I don't need (C40) and remove it. This is the point where the stomp came back to life.
I hope this info will help others to find their own suitable fix for this stomp.
Recap.
1) Remove MAX887 (U14) – (this fix is based on this device failing)
2) Remove 1000uf Cap (C40) – (removes the boot timing delay)
3) Remove 3.6V Zener Diode (D16) – un-necessary for 4.5vDC aux. Power and stops a weakened circuit that may need a little more juice from working
4) Jumper +pin (C59) to +pad (Removed C40) – to establish "power good"
5) Jumper +pad (removed D16) to pad-pin7 (Removed U14) – to route our new power in
6) Make a "C" cell sized pass-through dummy spacer for the battery box – to make 4.5vDC
7) Get a "Pin Positive" 4.5 vDC wall adapter for the aux. power input. – re-label this jack
8) Replace the four cheep switches for better. – option for lasting stomp performance
9) Throw away your warranty card.
"To the WiKi, batman!"
or at least the FAQ's...
:)
Regarding the "fix" just posted.
This does not address the input-pin on/off feature, where removing the input plug grounds pin1 of the MAX887 putting it in shutdown mode.
You will either need to remove the batteries, shove a guitar pick between them, or add your own power switching scheme, or just use the aux. power transformer.
This device is always on.
Makes me wish I'd bought the thing. :'(
To the Wiki, indeed!
:icon_exclaim:
P.S. to my fix Dead-After-a-Year post
Hasty post. Just wrapping things up today.
For the board to see the batteries with the MAX886 removed you will want to short pins 7 & 8 short together when you put the jumper on 7. You also will want to put a diode in line with the battery + to prevent any possibility of an adapter trying to charge the batteries if used.
:icon_exclaim:
Oh hell.. that's not right . STILL WORKING on getting the wall adapter/battery isolation right.
Don't short the pads (removed)MAX887 (U14) 7 & 8 together! Just move the red battery wire to the +pad where (D16) was removed and the jumper to (U14) pad 7 is connected and settle for three "C" cells for 4.5vDC for now.
Here ya go....
http://aronnelson.com/gallery/MrHuge/DL4_ps (http://aronnelson.com/gallery/MrHuge/DL4_ps)
(http://aronnelson.com/gallery/albums/MrHuge/DL4_ps.jpg)
Thanks for the write up, Tombeau, and the schematic, Mr Huge! I will take out my dusty busted DL-4 and give the PS a look. T'was once my favorite pedal...
VERY interesting thread. ¿Wanna see the motherboard of my DL4?:
DL-4 Board (http://www.pisotones.com/varios/DL-4/PCB.jpg)
More shots here (http://www.guitarristas.org/forum/viewtopic.php?t=4924&postdays=0&postorder=asc&highlight=dl4&start=30)
I just "fixed" my DL4 thats been taunting me for 2 years now, it was being really weird, nothing as simple as the power supply issue thats been talked about here, though the schematic Mr Huge posted of the PS has been helpful with some other mods. The DL4 was just making crackles instead of delay sounds, but certain things still worked in the DSP, like the dry signal, and some of the non delay effects, like the swell, sweep, and the overdrive in the tube echo model. In the looper sometimes it would work right, but then it would crackle and skip part of the loop. What I imagined was that it was like the memory of the loop was being read and all of a sudden, it would read it super quick and the loop would take milliseconds, and would just sound like a crackle. I tried replacing the crystal, but that didn't do anything, also all the clock test points were consistent, even when it was screwing up. I replaced the DRAM with another one and it did the same thing...
What I ended up doing was taking apart my functional FM4, using the heat gun to desolder the DRAM off the DL4, sticking the DRAM on the FM4, and switching the eproms and enclosures. So far both of them work fine. Lord only knows why ???. I must admit they're pretty fun pedals for making weird sounds, especially with my archaic guitar synth. Tasteful? Pretty unlikely.
Whoops! Wrong thread!
Here we go again >:(
My DL-4 (SW version 1.3) started acting erratically for the second time in a year. The first time it was a matter of bad power surge. Now the power outlet in under specs but I think the failure is still related to power issues. I feed it with a DIY adapter, simply a 220V-9V 1A AC-AC transformer in an old box of slides :D but tensions are OK. The DL4 was acting erratically, sometimes working but hanging shortly after. Sometimes hanged when pushing any of the stomp buttons, sometimes when rotating the models encoder, sometimes by itself... :icon_rolleyes:
I dismantled the unit (*) and all voltages were OK for the Zener, charge pumps and regulator as stated previously but found that C40, the big PS filtering capacitor (1000uF 16V) near the power jack was a bit too hot for my tastes. I've replaced the capacitor and now the DL4 works again as a charm. Perhaps the capacitor was faulty and the ripple was upsetting the digital circuitry...
(*)
Board (big pix): http://www.pisotones.com/varios/DL-4/PCB.jpg
EPROM: http://www.pisotones.com/varios/DL-4/EPROM.jpg
Pot shafts without buttons: http://www.pisotones.com/varios/DL-4/Potes.jpg
Detailed view (be careful when prying :icon_wink: ): http://www.pisotones.com/varios/DL-4/TWEAK.jpg
Under the hood: http://www.pisotones.com/varios/DL-4/Pulsadores.jpg
Actuator: http://www.pisotones.com/varios/DL-4/Pulsador.jpg
Dismantled actuator: http://www.pisotones.com/varios/DL-4/Pulsador_despiece.jpg
Alright, I give up! :icon_frown:
I've tried all I can imagine and then some... The DL-4 works 1 out of, say... 10 times, but when it works (works OK with all delays) it hangs a few minutes later.
I've measured voltages. All are OK as stated above in this topic ( D16, U14, U20 and U21). Same with 9V AC, 9V DC or batteries.
I've replaced all electrolytics and some tantalums.
I've replaced both 1N4002 rectifiers and the 3.6V Zener
I've checked all diodes
I've replaced the input power socket (intermittent contact)
I've replaced the PLCC 21-pin EPROM socket ( :o )
I've resoldered each and every pad in the board ( :icon_mad: )
No luck so far. Always the same erratic behaviour. Sometimes it recovers with a Hard Reset of the CPU (U7, pin 4) only to hang again shortly after.
I have noticed two things:
- The 3.6V Zener goes much too hot for my tastes when fed with external power
- DAC testpoint ( above D7 LED (http://www.pisotones.com/varios/DL-4/PCB.jpg)) gives no DC reading when failing to boot.
¿Any ideas?
Bump
Is there any other methods or areas to check out regarding the trouble shooting posted on the first page?
I checked D16, U14, U20, and U21 with all the voltages checking out. There is this white spot on U7, not sure if that is a manifestation of a failure or just paint/blotch of some sort..
(http://i157.photobucket.com/albums/t54/Beedoola/F9F88032-D099-4B7D-8062-FD5F57685871-18391-00000628E1B5224F_zps0e230f02.jpg) (http://s157.photobucket.com/user/Beedoola/media/F9F88032-D099-4B7D-8062-FD5F57685871-18391-00000628E1B5224F_zps0e230f02.jpg.html)
bump. please help :(
can someone give their voltages from the test points - from their working DL-4.
Mine are (in DC)
MCLK - 1.5v
LRCLK - 0.7-9v
SCLK - 0.4-6v
ADC - 3.1V but it drops down to 2 so and then back up
DAC - 0.0-1v, it gets cycling.
so I can get it to power sometimes but it get stuck. You hear the relay click, the lights flash - first two LEDS and then the second two but gets stuck on the 3rd and 4th LEDs - they just stay lit.
Press the EPROM chip. It has a tendency to get loose from the constant pounding on the pedal :icon_mrgreen:
Its pressed into the socket pretty good.. I also throughly cleaned the pin contacts on the socket and the chip.
Also, the power up issue and LED freeze occurs even without having a cable plugged into the Mono Input. And I have to wait about maybe 30 seconds or more before I can attempt to power it again. If I try to power it up again right after another power up - nothing happens. I know someone mentioned C40 is for the timing boot delay but I'm not sure if that would cause the issue.
Can anyone provide the test point voltages?
is it odd that my DL-4 board is missing this transformer thing... My version is V1.3, so says the EPROM...
(http://i157.photobucket.com/albums/t54/Beedoola/85AB0EEA-47CC-499F-AE5A-45BDB45B81AB-912-000000A2BFF9B583_zps5203508d.jpg) (http://s157.photobucket.com/user/Beedoola/media/85AB0EEA-47CC-499F-AE5A-45BDB45B81AB-912-000000A2BFF9B583_zps5203508d.jpg.html)
anyone?
can anyone share there readings from the test points? Mine are now:
MCLK - 1.590dc
LRCLK - 3.2dc
SCLK - 3.2dc
ADC - 3.2dc
DAC - 3.2dc
area around the diodes gets crazy hot.
Quote from: beedoola on May 03, 2013, 08:16:59 PM
can anyone share there readings from the test points? Mine are now:
MCLK - 1.590dc
LRCLK - 3.2dc
SCLK - 3.2dc
ADC - 3.2dc
DAC - 3.2dc
area around the diodes gets crazy hot.
MCLK, LRCLK, SCLK are test points for different clocks in the system, they are very fast square wave clocks to run the digital stuff, so they aren't a DC voltage. You would need a scope to inspect them, unless your multimeter's AC setting measures waveforms up into the MHz.
Sorry your pedal stopped working, I banged my head against the wall for hours trying to get mine to work and gave up. There just isn't enough documentation out there to debug the digital section.
Quote from: rockhorst on April 27, 2013, 07:24:56 AM
Press the EPROM chip. It has a tendency to get loose from the constant pounding on the pedal :icon_mrgreen:
You made my day bro!
Dl-4 completely dead. No voltages.
Changed all caps (100uf & 220uf) and diodes (2x 1N4007 & 3.6V zener), the voltages get right but pedal not working.
Press the Eprom and it back to life.
OK - so we can possibly link in the technicians guide from the Apple II here... lift [pedal] up off hard surface around one foot, drop on surface to land square, if not resolved open casing of [pedal] and firmly press on all socket and slot housed components.
Can someone help me out here. I got another dead DL-4 (I was able to sell my last dead one for what I paid for it broken, so I evened out).
D16 was reading open. I replaced D16 and D11 with 1N4001. I'm getting 9.3v at D16 and 4.6 at D11. I'm getting 2.2v at U14. At the voltages right for the diodes?
I had to replace D16 again as it fried up upon replacing it - this was before replacing D11.
I'm getting 4v on U20 and 3.2 on U21....
So what you are just buying blown gear, fixing/reselling it and asking us to troubleshoot?
Good business model mate.
I'm also having DL-4 trouble. 3.3V, 6.5V, 5V and -5V all measure OK and don't shown any ripple on a scope. I also see a 12MHz clock on the MCLK test point. When I plug a lead into the input the unit usually doesn't start up, and maybe 1 in 10 times it will switch on some LEDs and then freeze. Very occasionally I have heard the relays click as well. I'm starting to suspect the EPROM, I'm currently waiting for a PLCC adapter so I can dump it and see if it looks OK. In the meantime, does any have any other suggestions? Is there a known working dump of the EPROM out there that I could use to bring this back to life?
I got another Dl-4 recently for $20.
This one isn't dead, it powers up and passes the dry signal when in True-Bypass mode, but when an effect is engaged, I get white noise. If I back the mix off completely, Everything is fine.
What I've done so far:
Both reset types: A & D switches (factory reset), A & C (bypass type) - the noise is preset in the Spill over bypass but not True-Bypass.
Re-seated the EPROM chip - cleaned the socket and chip pins with Deoxit.
Cleaned the Input jacks with Deoxit.
Any suggestions? Could this be a bad eprom chip? I thought I recalled reading accounts by people saying that if the oscillating feedback is to harsh it can damage something.
did U check all the power supply voltages??
both source AND distination??
here's a new link to the power supply schematic:
http://aronnelson.com/gallery/main.php/v/MrHuge/Line+6/DL4_ps.jpg.html?g2_imageViewsIndex=1
look over the solder side of the pcb for cold solder joints, especially around any sockets.
afn
Quote from: toneman on July 01, 2014, 07:51:27 PM
did U check all the power supply voltages??
both source AND distination??
here's a new link to the power supply schematic:
http://aronnelson.com/gallery/main.php/v/MrHuge/Line+6/DL4_ps.jpg.html?g2_imageViewsIndex=1
look over the solder side of the pcb for cold solder joints, especially around any sockets.
afn
voltages check out. I desoldered and resoldered the EPROM and Relays, no change.
So when the Mix is down, clean signal is fine.
Also, in Sweep mode, the noise drives the LFO. Does that possibly help in locating where the issue is?
bump
Do you need 6.6v at U20? I replaced the U14 cause it was dead - not putting out 3.3v, but now it is. I'm getting 6V on pin 8 of U20, 5V at U21.
I got the DL-4 to power once, the bypass worked but no delay/effect. Then it stopped working. I got it to boot half way and then it stopped - doing the hard reset.
thanks for all the information on this thread i've managed to fix a dead DL-4 i got off ebay
with batteries, all the voltages are fine and delay sounding great
i still have some problem using an external 9V AC power supply (2000mA)
at 6V DC point I have about 14VDC instead. I haven't tried if the delay works because rating for the MAX887 is maximum 11V so I don't want to burn something again.
if i lift D11 cathode off the pcb and measure the voltage i got about 5.5V DC which should be fine
if the diode is put back on the circuit the voltage rises to 14V DC
i am wondering what is the problem here. any help is highly appreciated
power supply schematic
http://aronnelson.com/gallery/main.php/v/MrHuge/Line+6/DL4_ps.jpg.html?g2_imageViewsIndex=1
I'm working on a dead DL4 as well. What parts did you replace?
Attempt at reviving a dead thread....
So I traded my micro chorus and phase45 script for an mm4. The guy gave me the ps and the pedal for it, but said the power supply doesn't work but it works fine off batteries. I got it home plugged it in and he was correct.
After doing some diagnosing and with much help to MrHuge and Tombeau's posts in this thread, I was able to to determine that the zener was bad, as well as the MAX660.
I've now replaced the zener and the two rectifier diodes, the 1000uF cap and the Max660. But am getting bizarre readings...
The 6VDC is reading as 11VDC, and the 6.6Vdc of the output of the max660 is reading 2.45VDC. However I am getting the 3.3 VDC out of the MAX887. Very strange. I would have to guess that something is amiss in the rectification circuit still and i must have damaged the MAX660 when replacing it (i dont have a HA rework station so am using the copper wire/soldering iron trick to remove the smd components
Other than replacing the zener and MAX660 again...any thoughts on what could be wrong? Possibly C59 and/or C48?
The MAX660 says it's absolute maximum supply voltage can be 6VDC. which is odd because its supplied 6.6V according to the DL4 PS schematic.
At the end of the day I might just have to scope all the voltages to check for ripple/etc.
Schematic: http://aronnelson.com/gallery/main.php/v/MrHuge/Line+6/DL4_ps.jpg.html?g2_imageViewsIndex=1 (http://aronnelson.com/gallery/main.php/v/MrHuge/Line+6/DL4_ps.jpg.html?g2_imageViewsIndex=1)
MAX660 DataSheet: http://www.ti.com/lit/ds/symlink/max660.pdf (http://www.ti.com/lit/ds/symlink/max660.pdf)
Thought Id add my experiences to the list.
Just had 4 DL4s in for repair. 2 were easy fixes. The other 2 as below
1, MAX887 had failed as described by others.
2. All the power supply points were as expected, but the unit would not power up. After searching around the circuit I discovered that the EEPROM was not working. I removed the IC then reinserted it. It then burst into life. I assume a failed connection on the EERPOM socket. I sprayed the connector with contact cleaner and reassemble it.
So may be worth a try to those that have a non powering DL4...
I'll add my woes to the list, too... Two DL4s, both dead.
One of them after a bunch of Deoxit appeared to be stuck on one preset, and refused to pass any audio, and after sitting testing different points for voltage mysteriously started working again... Make sure that when you use Deoxit, you follow it up with some canned air or a little rub with a cloth to really clean it up. Seems it just needed a jolt somewhere and it was fine.
Second DL4, after some Deoxit, started passing signal in bypass mode and showing proper LEDs and control (as in the presets would load, and delay time knob changed the 4th LED rate), but passed zero signal in effect mode. After measuring voltages on the working DL4, I figured out that the MAX660 is bad, as I get great voltages up until then (which is I imagine how I'm getting what looks like proper control over no actual signal effecting), but after that where I should have 6.6V and 5V around the U21 transistor, I have ~2.5V and ~0.8V respectively. Ordered a couple MAX660 to try the swap, hoping that works out.
To those that find the power diodes heating up or hot... The working DL4 I have does this too. I don't think it's a problem necessarily, though I'm sure it makes them more prone to fail. Make sure they're among the first things you check, though I'm sure if you're reading this far you've already checked them. On that note, can anyone give any advice as to alternates/replacements that would be more heat-resistant or reliable, yet still do the same function?
Other than that, if anyone needs any voltage points tested that aren't on Aron's handy DL4 PS schematic, give me a shout either here or PM... happy to help builders in need.
these power diodes - what type number are they? you can provide diodes with heatsinks just by standing them on longer than normal legs, so they sit 10mm or so above the board.
Quote from: Johan on January 24, 2006, 03:20:08 PM
does any of them work with batteries?..
I used to work as repairman for the scandinavian Line-6 distrubitures, so I think I can help...due to signed non-disclosure agreements, I cant send you copies of the schematics, but i can guide you through...
..so follow me now...
...first thing to do. Plug a monoplug into the mono input, press footswitches 1 and 4 down and apply power. dont let go of the switches for at least 5 seconds. if nothing happens, its time to open up.
from the AC-in, power goes throu a 3,6v Zener ( D16 ) then on through D11. the 3,6v zener are known to fail, but doesnt affect battery operation.
after D11, power meets up with the battery in... next comes U14, a little 8-pin ( SMD ) MAX887. this one takes things down to 3,3volts ( mesure pin7/ signalground ). if you have 3,3volt on pin7, go on to U20.
U20 is a MAX660 wich is a voltage doubler. check the DC voltage on pin1 ( or 8, they are tied together ). if you have 6,6volt here, next in line is a tiny thing called LM3480 ( U21) this one will even out things for the digital domain to 5 Volt...if you havnt found fault yet, and reset doesnt work..dont bother...
..so the most likely suspects are
1: 3,6v Zener ( D16 )
2: MAX887 ( U14 )
3: MAX660 ( U20 )
4: LM3480 ( U21 )
hope this help...
johan
Hi Johan, thanks for the info. I have followed your steps and have found that the MAX887 is giving out 5V instead of 3.3V. Any idea what is causing the fault? I have cleaned the board and reflowed some joints and it fixes the problem briefly, before something goes and it doesn't power on. Thanks
I've used this thread over the last few years to fix a couple Line 6 modelers, and I was hoping someone might be able to help me understand one particular aspect of the power section a bit better - what's the deal with powering with 9VAC vs 9VDC? 9VAC is recommended, I've read that 9VDC works as long as voltage polarity is reversed from the center negative we typically used, but I've been able to power mine up using both polarities without issue. Can anyone help me understand why?
Also, I just fixed another one by replacing the D16 zener (using part number 1n4729), and the new one is getting crazy hot (tried both polarities 9VDC), as reported above. Based on the schematic, is that to be expected? Possibly a design flaw as the zeners are known to fail, and I can't imagine the heat helps?
For reference: (http://music-electronics-forum.com/attachments/34038d1432158549-dl4_ps.jpg)
Quote from: drummer4gc on July 30, 2016, 07:30:20 PMAlso, I just fixed another one by replacing the D16 zener (using part number 1n4729), and the new one is getting crazy hot (tried both polarities 9VDC), as reported above. Based on the schematic, is that to be expected? Possibly a design flaw as the zeners are known to fail, and I can't imagine the heat helps?
I went down the same rabbit hole this week (in the hopes of ordering all my replacement parts from Mouser) and after much hemming and hawing I opted to order part number 2EZ3.6D5 instead from DigiKey since it's rated for 2w. Reading your post now I'm thinking I made the right call! I'll post an update when the parts arrive.
And for reference, here are the borked components I'm replacing. Seems like a trend with these pedals!
1 x 1000uf 16v Radial 1000 uF 20 % 16 VDC Aluminum Electrolytic Capacitor
1 x 100uf 25v Radial 100 uF 20 % 25 VDC Aluminum Electrolytic Capacitor
1 x Texas Instruments LM3480 Series 5 V LDO Voltage Regulator
1 x Maxim Integrated MAX887HESA Voltage Regulator
1 x Maxim Integrated MAX660CSA Voltage Regulator
1 x Microsemi #2EZ3.6D5 3.6v Zener Diode, DL-41