Re: 2 dead monitors, blueh h94w and amw x1700ds

More test results, I did this @ 1kHz as I thought that it would give more accurate results with SMPSs (above 4kHz most of the elite caps become inductive). I don't think any of them have failed as such, but they are just not low ESR types and don't work well with HF power supplies. I've ordered replacement Panasonic ones that should arrive on Monday so I will see then if that really was the problem.

Make Size Voltage C(uF) ESR tan d
Elite 10uF 50v 8.73 3.82R 0.211
Elite 1mF 25v 939 35.6m 0.211...

Re: 2 dead monitors, blueh h94w and amw x1700ds

I measured most of the larger (1mF) caps from the AMW today - the 16v ones all had roughly the same results, as did the 25v ones. I've posted the worst performing caps below.
(@125Hz)
25v, 1000uF
tan d: 0.057
cap: 951uF
esr: 66.55mOhm

16v, 1000uF
tan d: 0.096
cap: 993uF
esr: 123.8mOhm

datasheet for these caps states a tan d of 0.18, but no esr values. They look OK to me - does anyone have any other ideas about what might be wrong.
Thanks!

Re: 2 dead monitors, blueh h94w and amw x1700ds

Here are the images of power supplies. The slightly burnt resistor on the Hyundai board (top center) is where I discovered how the feedback from the 15 or so volts from the backlight works. It has a zenner and a resistor designed to pull up the 5v if the 15v gets too high. I was running the 5v off a bench supply so the resistor got quite warm quite fast. That section still works though.
Also I have started changing caps on the Hyundai board on the 5v rail. I've put in a Nippon Chemi Con (large, left hand side) and a Sanyo (near...

Re: 2 dead monitors, blueh h94w and amw x1700ds

I am quite up for fixing these monitors myself but I just wanted to make sure that if I spent £20 on capacitors there would be a chance I would fix the screens. The caps in the AMW are mainly elite and on the hyundai they are su'scon and samxon.
I've been doing quite a lot of work on ethernet over AC adaptors with dodgy caps and I've found that the (bad) caps they came with (jackcon) are OK provided they arn't subjected to too much ripple. They had a CLC filter for the 3.3v and only the first C needed replacing with a low ESR...

Re: 2 dead monitors, blueh h94w and amw x1700ds

The one with a digital decade pcb is from an AMW x1700DS-A1 and the other monitor is a Hyundai BlueH H94W

Hi, I have two monitors with PSU problems and I was wondering if anyone had any ideas on what could be wrong with them before I replace all the capacitors.
The blueh monitor works for a few minuites before cutting out. The monitor has to be left for a while before it will work again (cool down?). The voltages are OK until the screen cuts out, at which point the 5v rail drops to 4.6. Runnning the monitor off an external 5v PSU solves the problem.
The board has ILPI-068 written on it.

The other monitor doesn't turn on (not even the LED). I left the monitor at work so...