Hi, I was able to get this pretty expensive spot meter (to use with analog cameras) pretty cheap, but after about a year of use, it failed on me.

It always emitted a high pitched whine, which I wasn't sure if it was normal or not, but after using it in -25°C weather the display started showing very low contrast (barely readable from a normal viewing angle).



I took it apart and found a couple leaked capacitors and was able to replace them just fine. The PCB had very mild corrosion, which I treated and tested all the affected traces for continuity.

Now the meter powers on fine without any whine whatsoever, but the display still shows very low contrast. I've looked at the datasheet for the LCD driver IC (Hitachi HD61602H) and to me:
VREF1 ~5V
VREF2 ~5V
V1 ~ 4.5V
V2 ~ 3.5V
V3 ~ 2.5V
seem fine. Is there anything obvious I'm missing?

I don't see any variable resistors on the LCD board:





but one of the other two has a couple:




I'm not sure what they do so I've left them as-is.

Here is a link to the datasheet. I've also added a photo of the third board as well as a screenshot of the datasheet/my readings in the attatchments. Many thanks in advance!

 

Hey! Love the thread here. I'm actually having a similar issue on my own meter and was curious how you were able to get it apart? I have removed 5 screws so far but the top section is stuck. Any advice here?

 

I have removed 5 screws so far but the top section is stuck. Any advice here?

I'm still on holiday but I didn't want to leave you hanging... I don't remember everything because it's been about a year or so since I took the meter apart intitially.

Have you tried taking apart the flash socket? The "weird" screws are around the flash and the tripod screw. Other than that I think the rest were very visible from the outside, no sticker-peeling necessary.