SMR-4 mkII voltage a tad low during test

just got to the testing part step 5 and i’m getting 3.33 v on the red test and -3.07 v on the green test . i have checked polarity on everything and the using a 9v dc that’s right for it. also checked the 5th pin on the LT1054 and i’m getting -8.07 v on it… on the 7905 i’m getting 0 , -8.07 , -3.07 and on the 7805 i’m getting 8.32 v, 0 , and 3.33v … where to start to figure out whats wrong thanks in advance

Do you have a different power supply that you could try?

If that’s not the case, next step is posting a picture of each side of the board… :slight_smile:

no other power supplys but i know it’s a good one for it coming with the photos should be able to see them there

OMFG ignore wow i’m retarted i put the 7805 and the 7905 in the opposite slots… will post if i still have issues after

Well… Only two things left now :

  • 1)Finish building shruthi-1. Rejoice once done.
  • 2)Wait for fcd72 to wake up and tell you your position on the shruthiversum ^TM^ caste
    (Damnit, I can never get the superscript TM to work …)

Here we go:


Its™ so™ easy™ …

@here® ™ = [alt][2]

how many times…:wink:

How Many Times ?

lol i hope i didn’t burn anything out… i’m having the toughest time trying to get these regulators out of their slots… i got frustrated last night so i gave up for the night… how would yall get them out. usually i just reheat the solder and gently pull… but since they have 3 leads it’s a b*tch to get the heat to all three.

Heat leg one, pull it up 1-2mm, heat leg 3, pull that up 1mm, heat leg 2 pull it up, start over… (Or just go 1 - 2 - 3)

Make sure that you do not apply heat for more than 2 max 3 seconds, and make sure that the area+leg have cooled down before heating again, or you will end up lifting a pad :confused:

get some new vregs from your local supplier (standard stock items) and cut the legs of your old ones. desolder the legs one by one, that’s the safest way you can do it.

ok got some new v regs… when pulling out the last ones. i have what looks like the + top pad of the 7905 is gone but the bot is still intact… is this a problem? all the rest of the pads where ok i just had some solder go thru the + hole and attach on both sides so i think when i heated and tugged the pull the old pin out it took the pad with it *update indeed yhis is what happened i found the pad still attached to the old pin … what can i do?

Use a piece of wire to connect the pin where is supposed to be connected with the pcb traces.

actually looking at the schematics . the + for the 7905 doesn’t connect to anything. so would it luckly be ok?

Of course it does, it is connected to ground.

The ground is connected on the bottom side of the board… So the pad you mis is probably no problem… It probably also got loose because it is not connected to anywhere.

oh thank god… thanks alot for yalls help