Author Topic: DL4 No Power  (Read 302 times)

Corey5150

DL4 No Power
« on: June 01, 2022, 12:51:35 AM »
So, I just recently picked up a non functioning DL4 for ten bucks. I love to tinker on stuff, so I figured it may be a fun project. Seems to be a similar problem with these after extensive googling. And Iíve tried every suggestion pretty much mentioned.

I did not get a power supply, so weíre running off 4 brand new batteries (I will be getting an adapter tomorrow though). I checked for cracked solder joints, couldnít find any, ran over some of them anyway. The diodes seem ok.

Now this is where Iím getting a little screwed up. This isnít the same board revision that uses the Max887/max660. This uses a RT7237, which has a different pin out. The voltage I get here shows 5.50 in, and 3.33 out - so, so far so good.

Then it goes down to another IC (which is supposed to be the doubler - the max660 in other revisions) and the input is showing 3.33, however the output on the pin is 1.22, it then Travels through to resistors to reach a voltage of 5.05. From my understanding Iím looking for a voltage of 6.6.

My thought process right now, is this chip needs to be replaced, but Iím not exactly sure especially with those resistors. And I canít find any info on what this IC is called. It looks to me like DL=1E followed by a 20Y below it.

Continuing with my tracing it leads to an S03A and 5.05 on pin 4 and 5, 2.5 on pin 6, -4.88 on pin 2, and -2.45.

Any help would be greatly appreciated :)

PRR

Re: DL4 No Power
« Reply #1 on: June 01, 2022, 01:33:53 AM »
Welcome!

> DL4 No Power

The Line6 DL4?

A schematic would be handy here:
https://music-electronics-forum.com/forum/effectification/guitar-effects/36974-line-6-dl-4-troubleshooting
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Sweetalk

Re: DL4 No Power
« Reply #2 on: June 01, 2022, 05:41:30 AM »
Sometimes those voltage doublers have issues with the soldering. Remove it, clean the pcb really well and any residue of the old soldering and solder it again using solder paste or flux. Had the same issue in a couple and came back to life with that. If is not working, replace the IC. Maybe a good picture of it will help us to get the part you need.

Corey5150

Re: DL4 No Power
« Reply #3 on: June 01, 2022, 08:34:10 AM »
Yup! Its the old line6 DL4 - I managed to grab one of these and a Fulltone Full Drive 2 Mosfet for 10 bucks each. The FT was a fairly easy fix through tracing the signal. I knew the DL4 would be a bit of a challenge, but I was hoping it would be something simple LOL

I've attached two photos, one is the schematic of the power supply. (Not the correct revision though - can't seem to find it anywhere)

The second one is one I found on the Line6 forum - asking what the IC in question is called, he references different letters/number then I can see on mine. I'm going to try and get a picture - I'm just not sure it will focus on something that small.

As I've mentioned about the schematic, the U numbers are different so what I can see (the path it follows is VERY similar) and because of that U14 would be U23 (Max887 =U14, RT7237 = U23), and U20 would be U24 (Max660 = U20, ??? = U24) and obviously the pinnout is different as well. I also emailed Line6 support asking if they can identify the mystery IC.

EDIT: I attached a previous photo I took in the meantime, I'll try to get something a little more clear. (BUT if you zoom in, you can get an idea of what I saw [DL=1E20???])








« Last Edit: June 01, 2022, 08:36:07 AM by Corey5150 »

antonis

Re: DL4 No Power
« Reply #4 on: June 01, 2022, 09:05:12 AM »
Sorry but I'm confused a bit..

What are the voltages on IN & OUT of LM3480..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Corey5150

Re: DL4 No Power
« Reply #5 on: June 01, 2022, 09:10:44 AM »
Heres a much clearer picture, after some creative lighting


Corey5150

Re: DL4 No Power
« Reply #6 on: June 01, 2022, 09:24:13 AM »
Sorry but I'm confused a bit..

What are the voltages on IN & OUT of LM3480..??

There is no LM3480, it runs from the RT to the mystery chip to an S03A (LM2664). After looking at the data sheet... perhaps its meant to have a lower input voltage than 6.6v?




antonis

Re: DL4 No Power
« Reply #7 on: June 01, 2022, 03:15:13 PM »
Theoretically, it inverts any input voltage in the range of 1.8V - 5.5V..

Without specific circuit implementation, I can't say anything more..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..