Positive voltages at V- and AV-

[Bill]

Eric,
Thanks for your help. I found that C13 is shorted out. What value capacitor should I use and how do I remove and replace a surface-mounted cap?

[Petroid]

What value capacitor should I use

According to schematic C13 is 0.1uF. Also it is paralleled with C14 and C15. How did you find out that faulty one is C13?

and how do I remove and replace a surface-mounted cap?

Basically you heat it with hot air and pick up with tweezers but if you don't have hot air gun, you can just heat it with soldering iron. The cap will stick to it and come off the board. To replace the smd with just a soldering iron is a bit tricky but I managed to do it a couple times. You place a smd on its place, hold it with tweezers or wooden toothpick and then heat its sides with soldering iron.

[Ric82]

Eric,
Thanks for your help. I found that C13 is shorted out. What value capacitor should I use and how do I remove and replace a surface-mounted cap?

please note Corrected version for my post on 23/08/2017

Hello
Ok your board is new one, so here C13 is SMD, as i could see on your (poor quality )

So C13 would be a 0.1µF, and 50v on the 0805 smd size

http://fr.farnell.com/walsin/0805b104k5 ... dp/2496944

To do a good work, you need something like that to see what you do

http://i.ebayimg.com/images/g/RXEAAOSwa ... -l1600.jpg

Flux also needed to do a good solder too like that before soldering the new capacitor

http://www.ebay.com/itm/5pcs-BGA-SMD-So ... SweW5VaRks

It is possible to do without sure but you'll have to do it with special care. To extract old capacitor , you have to heat the 2 sides alternatively (and quick) to lift one side and after the other wiyh tweezers (if you don't have air gun)
Heating the two side alternatively permit to lift one side a few without breaking the capacitor and you need to heat enought to make it easy to lift the two sides without damage the two solder points on the card
(pcb)

if you have two litle soldering guns it is possible to put one on each side to lift it directly (but gently too...)

Then you clean the two solder points on the pcb with desoldering braid (tresse in french) and the gun to retire the old solder
https://www.jlelectroniq2.com/PBSCProdu ... %5FD%5FBwE

Put juste a few new solder to do the points clear and bright with gun, then it is ok to receive the new one capacitor smd


regards Eric

[Bill]

I'm sorry but I may have been mistaken when I said C13 was shorted out. Petroid's comment about how did I know C13 was shorted made me re-examine what I was doing. I was testing the capacitors for continuity using a multimeter while the capacitors were still in the circuit which, according to what I just read on testing capacitors, is a not a proper test. Is that correct?

I redid my improper tests under a magnifying glass so I was sure where I was touching the meter's probes and both C12 and C13 indicated 0.03 M ohms while they were attached to the circuit board so they are not different in behavior.

I'm afraid to try to remove C12 and C13 for fear of messing up the board and/or them so I'll try the test with the resistor that Eric suggested in the same post as he suggested testing C12 and C13. Everything else in Eric's post tested out OK.

Thanks for the reference to the schematic. I didn't know that was available online.

[Ric82]

No matter ! that's the job !!!

Like Italians say...10 times you measure...1 time you cut ! lol

[Petroid]

Thanks for the reference to the schematic. I didn't know that was available online.

No problem. They're right there on jye-tech website: http://www.jyetech.com/Products/LcdScope/e150.php