Hey thanks for the reply.
I'm having trouble getting replies on other forums so I'm glad I've finally found someone with more knowledge than I have
May I ask which point on the circuit board you're getting your power from? And how much volt is it?

 

I have more than one DVM. I used a volt meter to find the switched 9v.
If I have to, I could open the meter and take a picture.

 

Oh you really would do that for me? It's kinda hard to use the meter to measure itself I was hoping for 5V but 9V could work as well.
By the way, I've found that adding a touch sensor can be added without using any more components. When I succeed I'll let you know. I think it will be the easiest backlight mod there is.

 

Would have been better to apply hot glue at the solder connections.
Don't be confused by the battery connector - sign on the print. That V+ marker where the wire connects is the positive 9v leaving the switch.
The resistor is at the - point.

 

Thanks a bunch!
I'm waiting for parts from China so it could take a few weeks but I'll make sure to post the result.
Thanks again!!!

 

I promised to post the resilt.
Here it is:

 

Very nice! Like the red leds.
How much current is actually going through the LEDs?

 

12mA
Before istalling the circuit I'd used a resistor so the LED's + resistor were only using 4mA and I thought that would be enough. However when I'd put them in place I was very disappointed by the brightness. Since I'm not using the backlight often I figured I might as well use a lower value resistor to turn up the brightness. Even with the backlight constantly on an average 500mAh 9V battery would still last me around 25 hours. (meter + added circuit & LED's combined: 20mA)

 

OK, thanks. I'm using bright white leds and using 2+ma all the time. Not bright but very readable in any light.
You solution is cuter

Do you know for a fact that the touch module will not work at 9v?

 

The touch module needs between 2.0 and 5.5V so 9V will fry it

 

Hello,

First time poster here, actually just signed up to get a look at your picture

I was thinking of getting the UT61D, because it has the backlight built in, but the backlight is auto off after 10s on that one, which I think would be annoying, so I'm considering doing a mod on a UT61E like you did instead.

Are you happy with the reduced battery life? I probably won't be using this thing a ton, so I think it won't be a problem for me..

Just to be clear, you just connected the LEDs and the 1,2k resistor in series from V+ to ground at SG2 in your picture?

Also, could you maybe provide a picture of how the display looks with the backlight on?

 

What reduced battery life
The meter draws 2ma. The leds draw 2ma. I have not had to change the battery yet and it's the one that came with the meter. Nothing special.
The display is bright enough to read in low/medium light. No brighter than needed. If you want more light change the resistor. The light is even - not spotty.

 

I completed my mod yesterday! although the ground connection was not in the same place as on your picture. They seem to have changed it.
I used a 220 ohm resistor and the display looks real nice. However I noticed that it shifts in brightness when I switch to cap and freq mode (gets dimmer). It also shifts when I do continuity and the leads touch (gets brighter). Have you noticed anything similar?

I'm also worried that it might be affecting the measurements. The voltage seem to fluctuate more when leads are not touching anything. On mV range it even goes straight to overload and I'm not sure that was the case before the mod.

 

You are probably taking the voltage from wrong spot on the PCB.

 

Yeah, I'm starting to think you're right.. I Could really use some help with figuring out where to connect this..

 

I think I didn't hook it up right to ground. Connecting straight to - on the battery contact resolved the display issues. The fluctuating voltage seems to be normal. Some unmoded versions on YouTube do the same thing and when I touch the leads it reads 0V, so that seem's fine.

 

Glad you found the problem. Different functions may draw different current.
Use a good battery with clean connections.