Need help with my its-808 Took voltage readings and such??

Started by spiderman2812, March 11, 2007, 04:06:58 PM

Previous topic - Next topic

spiderman2812

Ok heres the deal i went to this thread http://www.diystompboxes.com/smfforum/index.php?topic=52462.0 and that is what happened i didn't know the pin layout was different and i powered it up! it didn't work so i changed the pin out around according to this link
http://pdf1.alldatasheet.com/datasheet-pdf/view/30083/TOSHIBA/2SC1815.html Powered it up and it still don't work. I followed the layout exactly and all i can figure is that powering it up screwed up the ic, trannies, diodes or all of them. So i did what everyone would do and took some readings.

Looking at jrc4558 with cicle in top left corner going down is pin 1-4 on left then going down is pin 5-8                         
Pin 1= 4.42v                                                                                                                                       
pin 2= 4.5v
pin3 = 4.41v
pin4= 0v
pin 5 = 8.87v
pin6=4.42v
pin7= 4.42v
pin 8 = 4.42v
 
now for the trannies
Q1 collector 8.87v
q1 base 4.13v
q1 emitter 2.5v
Q2 collector 8.86v
q2 base 4.12v
q2 emitter 0v
Here is a link to ggg's readings http://www.generalguitargadgets.com/pdf/ggg_its8_instruct.pdf
Hope some on can help i actually reordered all the diodes the ic and trannies today so i guess i could change them all out if all else fails. Thanks guys!!!

Barcode80

IC is fine, trannies are WAY off. you might have somehow fried them when you had the stuff crooked.

spiderman2812

I figured something like that may have happened. I also used a germanium diode for the clipping diode but that really shouldn't matter any way thanks anymore input would be appreciated.

studiostud

regarding the germanium diodes, I do know that they are much more sensitive to heat than other diodes so maybe you fried one while soldering?  Just a thought.
Builds Completed: Big Muff. Fuzz Face. Tube Screamer. Rat. Crash Sync. Harmonic Jerkulator. 6-band EQ. Rebote 2.5. Tremulus Lune. Small Stone. Small Clone. Microamp. LPB-2. Green Ringer. Red Ranger. Orange Squeezer. SansAmp. MXR Headphone Amp. Bass Fuzz.