Samsung LCD monitor slow to start up (Crystal aging?)
sounds like a crappy capacitor somewhere.
"Richard Thomas" wrote in message
...
I am trying to fix a 4-year old Samsung SM171P (aka GH17P) LCD monitor
that can take
several minutes to achieve initial synchronisation to either VGA(DSUB) or
DVI inputs
- it just sits there alternating its power light orange/green. Once sync
is achieved
it works fine.
I have the service manual / schematics and have been probing around the
main PCB. I
believe that the problem is that the monitor struggles to get past the
point where
the main GM5020 graphics processing IC measures incoming HSYNC/VSYNC
frequencies and
tries to match them to a mode that it supports. I'm hoping its not the
GM5020 as that
is a PBGA package so can't be replaced by hand.
I am wondering if the problem is that the crystal frequency has drifted as
it ages -
I see from the parts list that the crystal is unusually fine tolerance
30ppm:
CRYSTAL-SMD;24MHz,30ppm,28-ABX,16pF,50ohm
Anyone had similar experience with crystals / Samsung monitors / GM5020
IC?
Anyone know of companies in the UK that can supply specific
made-for-Samsung
components? (The equivalent of partsearch.com in the US?)
All help appreciated,
Richard
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