Ibanez AD202 acting very strange

[sonicblue99]

Hi guys, I've been banging my head against a wall trying to sort out my Ibanez AD202.  I can get chorus and flange working no problem.  However, the doubling and delay are the issue.  I've already recapped the unit as it was pretty gritty inside and I hoped it might be a power problem getting to the two mn3005. No luck.  So I figured it was probably my two mn3005 chips.  To test I replaced them with some mn3008 I had sitting around and both chips worked.  So the next thing I tried was swapping chips out one by one.  Long story short, both of my mn3005 will work in IC110 (delay) if I am using a mn3008 as IC109 (doubler chip.) However no MN3005 will work in IC109.  Is this a biasing problem or perhaps the mn3008 draws less power than the mn3005? I've also noticed I can not get the delay to feedback/osc (possibly due to underpower?)  I was thinking I need to check ICs 107,112, and 114 as well as diodes 101-102, 104, and 114.  Am I on the right path?

 

[dmp]

I'd like to help because these delays are awesome!  But I'm not sure if I have much to offer.
You are saying the unit works fine with MN3008s in both positions (delay)?
Can you measure the Vcc with the MN3005 installed to see if it is dropping?
I realize they are expensive, but maybe try different MN3005.
If it was working at some point in the past, a calibration issue seems unlikely. Unless it's a bad trimmer.

 

[sonicblue99]

Well DMP your comment got me thinking.  I got this unit not working and just assumed no delay meant something was wrong.  So, I just decided to try calibrating it.  And as soon as I get to the bias for the doubler she came to life.  Everything calibrated to pretty much the exact same (I took a picture before to compare) except the bias for IC109 (the doubler) mn3005.  I can only guess someone messed with it because if this was a case of tolerance drift due to age, I would think there would have been more adjustments needed. But either way this thing works and sounds great now. 

 

[Alban LG]

Hello everybody !
I'm posting in this old thread because I'have a "Regen" failure on my AD202 and it seems to me that there are some AD202's expert here !!
When I put Regen at min : I have 1 tap, when I put Regen to the max : I have 5 or 6 tap Maximum !! No more crazy feedback...
You know, where did these things come from ?
Lot of thx !!

 

[dmp]

Not sure I understand your question.
Sounds like maybe the regen is not as significant as it used to be?
Here is the page from the manual on calibrating the regen, maybe check this first