DNA 75 power

[TJDJ]

anyone come across this the problem i'm having is i set it 70w press the power button and it shows its only giving about 18w at 8.5a and only 1.8v i have tried the tank on my other 75w

and works fine its just on this mod as though it's not giving enough voltage to run at 70w checked wiring all fine 

[giz_60]

Can you post a screenshot/print screen of Device Monitor in Escribe with the following fields checked...Pack, Power, Power Set, Temperature, Temperature Set, Cold Ohms & Live Ohms

Edited December 6, 2017 by giz_60
Edit

[TJDJ]

hi thanks for the quick reply hope you can shed some light 

[giz_60]

Ok...now how about one while firing the device...

Edit: And what kind of wire & atomizer & mod are you using?

Edited December 6, 2017 by giz_60
Edit

[TJDJ]

i'm using the manta works fine on all my other 75w mods its got 2 fused claptons 3mm dia been using the tank a few months with no problems the problem is on a Athena pride which i have 2 and it works fine on one i even tried a different tank as you can see when firing it drops straight down

[TJDJ]

on this one i've ticked the currant & voltage which is showing 8.26a and only 1.88 v

[giz_60]

You are having a severe battery sag...either a weak/bad cell or bad/dirty connection...

[giz_60]

Look at your battery voltage...2.75v

[TJDJ]

yea thanks for that i tried a different battery that i know is good iv'e looked at the connections and seem ok 

[giz_60]

Your not getting enough power to the board...usually a sign of a weak/bad cell or a connection issue...if that mod has a screw on battery cover, then I would recommend cleaning all the threads etc. really good with so iso alcohol...I have had similar issues before with that type of setup and cleaning made a big difference...

[TJDJ]

ill go through all the connections it must be one of them as i say iv'e tried a battery from my other mod so iv'e ruled the battery out 

[TJDJ]

Think i have found the problem i'm guessing it needs a new board as iv'e stripped it down and checked the wire going to the board and it's showing 3.7v which is fine 

but the wire that comes from the board that goes to the 510 is only showing 1.88v from the connection off the board so i'm guessing it could be a resistor or something that's gone 

whats your thoughts

 

Edited December 8, 2017 by TJDJ

[VapingBad]

As @giz_60 said I think it is the battery sag before it gets to the board, the output voltage is tailored to the load and wattage and you can't look at it as a simple resistive loss.  My best advise would be to check the ground connections and the battery connections.

[TJDJ]

hi the sag is not before it gets to the board i have checked the power to the board while firing with a multimeter and is ok is the voltage coming back off the board to the 510 is where it drops i checked the out put direct from the board and thats where it's dropped to 1.8v there is no short or anything so im guessing a resistor or something on the board has gone

[giz_60]

The battery pack sag you are seeing in Device Monitor is an input voltage sag, not output...this is what the board is reading when firing...

[giz_60]

Quick question...is this the same mod that you posted about in another thread ( on the negative wire there is a plate that has a shrink tube on it then the wire at the other end and goes to the board)...if so, then you might want to consider replacing that wire with a solid piece of wire...just a thought!!!

[TJDJ]

yea i got that wrong its a plate on the positive wire under the shrink tube was like white tape or something the wire came from the connection of the top of the battery to the plate thing and from the other end of the plate it went to the board 

[giz_60]

Same thing applies..you might want to consider replacing that with a solid piece of wire. There shouldn't be any type of interruption of the circuit from the battery to the board. The positive wire would be even more so because the board is going to be make contact with ground through the mount screws & the metal case...

[TJDJ]

yea i will make a direct connection iv'e no idea what it is i even looked at my other athena pride which works fine and that for some reason has the same plate thing

[TJDJ]

This is on the good one just thought i'd post a pic of the plate thing 

[giz_60]

On all my 75's & 75C's, they have a solid piece of wire on both the positive & negative, with the exception of the mods that transfer the ground through the metal case. If you don't have a wire from the battery tube to the board, check all your board mount screws are tight as well...have seen that  problem before as well...just a thought...

[TJDJ]

thanks for your reply all my other DNA's is a straight wire but for some reason the pride has this

the wire from the top of that plate goes to the positive on the battery tube so it's confused me what the plate does

 

[TJDJ]

An update i think i have now found out what the problem was with it sagging i found the owner had try to repair it but the wire was only rated 8 amp which at the time i didn't know and with it open i could see when pressing the fire button the wire was smoking  so quick question again as i will replace the wire i was thinking 30 to 35 amp rated wire would that be correct 

thanks

Edited January 31, 2018 by TJDJ

[retird]

See the wire sizing in the  wiring section of this data sheet for the 75.... it may help....

https://downloads.evolvapor.com/dna75.pdf

[TJDJ]

Thanks for that retird thats helped a lot cheers