I've been given a HannsG HW173D LCD display that doesn't work, to keep or throw out. So I thought I'd see what was wrong with it.
Original Fault : display didn't light, power LED flashed Green then Orange, with a curious flick in color.
Opened it up, found bulging CapXon capacitors on PSU. Changed these for caps I had lying around, including 2 from an old TV set.
Original (CapXon) Replaced with
1000uF 10v 1000uF 25v (from old TV)
1000uF 10v 1000uF 16v (from old TV)
450uF 25v 450uF 35v (Sanyo, New)
This improved things. Display now lights up, LED turns green, then back to amber if no signal on DVI or PC input, or stays green if there's valid signal.
But the display isn't good. See attached pictures. Usually, I get the vertical colored lines. Sometimes I get a lava lamp effect with a few horizontal lines.
At this point I started googling and found this wonderful site! Thank you in advance! I kinda knew that bulging caps weren't a Good Thing, which is why I changed them, but didn't realise how bad the problem was. Spent hours reading the useful stuff you have here.
Measuring the voltage from the PSU board/ Video board connector, I noticed something interesting and wondered if it was relevant.
+5v is at +5.31 - +5.33v all times. But +12 changes. If PSU is powered on it's own, +12 line is +12.09v.
If Video board attached, LED orange, then +12 line is +12.91 - +12.94 (slight fluctuation)
If video board attached, LED Green, then +12 line is +13.95 - +14v (slight fluctuation)
With display connected and running, +12 line stays steady at +14.65v
Should this concern me?
Is it wortth me recapping with new, good caps? (the old TV ones were all I had to hand! ) Or does the fault seem more serious, given the strange display I've got on the LCD. Should I just chuck it out?
My knowledge of electronics is self taught and patchy, but not totally ignorant. (I knew bulging caps were bad before reading this site )
Any advice would be gratefully received.
Hope attached pics help. The 3 loose caps are the ones I took out (notice bulging on 2 of them). The close up of the caps near the heatsink are the ones I put in. I see no other sign of damage on the board or to other caps.
Stu
Original Fault : display didn't light, power LED flashed Green then Orange, with a curious flick in color.
Opened it up, found bulging CapXon capacitors on PSU. Changed these for caps I had lying around, including 2 from an old TV set.
Original (CapXon) Replaced with
1000uF 10v 1000uF 25v (from old TV)
1000uF 10v 1000uF 16v (from old TV)
450uF 25v 450uF 35v (Sanyo, New)
This improved things. Display now lights up, LED turns green, then back to amber if no signal on DVI or PC input, or stays green if there's valid signal.
But the display isn't good. See attached pictures. Usually, I get the vertical colored lines. Sometimes I get a lava lamp effect with a few horizontal lines.
At this point I started googling and found this wonderful site! Thank you in advance! I kinda knew that bulging caps weren't a Good Thing, which is why I changed them, but didn't realise how bad the problem was. Spent hours reading the useful stuff you have here.
Measuring the voltage from the PSU board/ Video board connector, I noticed something interesting and wondered if it was relevant.
+5v is at +5.31 - +5.33v all times. But +12 changes. If PSU is powered on it's own, +12 line is +12.09v.
If Video board attached, LED orange, then +12 line is +12.91 - +12.94 (slight fluctuation)
If video board attached, LED Green, then +12 line is +13.95 - +14v (slight fluctuation)
With display connected and running, +12 line stays steady at +14.65v
Should this concern me?
Is it wortth me recapping with new, good caps? (the old TV ones were all I had to hand! ) Or does the fault seem more serious, given the strange display I've got on the LCD. Should I just chuck it out?
My knowledge of electronics is self taught and patchy, but not totally ignorant. (I knew bulging caps were bad before reading this site )
Any advice would be gratefully received.
Hope attached pics help. The 3 loose caps are the ones I took out (notice bulging on 2 of them). The close up of the caps near the heatsink are the ones I put in. I see no other sign of damage on the board or to other caps.
Stu
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