Compaq 5017m 15" LCD Monitor Repair

[(*steve*)]

According to the chart, they should both read 0.2 ... 0.17 I would say is pretty close. But 0.05 is only 25% of it's proper ESR value. So, is it "reading bad" ?/QUOTE]

The problem is when the ESR rises to an unacceptable value. Having lower ESR will never be a problem (unless it's shorted )

If the external PSU is fine then I would be tending to think that bad capacitors is a less likely option. I'm not sure if you noted the PSU replacement previously -- it is a big heads up that the most likely place for that sort of failure is excluded.

There still may be a DC-DC converter on the device to get 5V or 3.3.V rails. If you can locate that, then check the capacitors there. Just check the ESR in circuit. I don't think there's any point in removing the capacitors at this stage.

I have not had experience with surface mount capacitors being bad. That's not to say they can't be bad, just that all things I've worked on with this fault have had through hole components.

 

[Tesla]

Freeze spray testing ...

Just a reminder. The display "static" occurs when the LCD is cold. As it warms up, the static gradually disappears. So, I let it warm up (display a picture) for 30 minutes, then ...

Lower board ( PS and Inverter):
No effect.

Uppper Board (logic and processor):
Freeze spray on mostly any random component (including the main Sage processor) brings the static/distortion back. After that part warms up again (usually 5-10 minutes) static gradually disappears again. I notice the Sage processor is running very hot.

General:
All connectors have been loosened and re-attached. I also removed and re-seated the eprom.

 

[Resqueline]

Freeze spray easily gets around a bit. Are you able to just dribble minute amounts on single capacitors etc.? Would you be able to glue a heatsink onto the processor?

 

[Tesla]

Freeze spray easily gets around a bit. Are you able to just dribble minute amounts on single capacitors etc.? Would you be able to glue a heatsink onto the processor?

I am being pretty accurate with the spray. The way it's acting ... I'm not sure what it means. I was hoping you would know.

I have seen passive heatsinks attached to video card processors but I wonder what kind of glue it is? Seems like it would have special properties since it would be replacing the thermal compound. I have a heatsink block from a 486 cpu cooler that might be thin enough to fit under the metal shield (not shown in pics).

 

[Resqueline]

Sorry, no luck.. I seem to remember coming across a similar screen with a power problem but it wasn't straightforward & I didn't bother digging too deep into the matter.
It could be that several components are "conspiring" and that improving the characteristics of either of them is enough to make the circuit stable.
There are special thermal glues available, but with the small power transfer needed here I'd settle for ordinary super/crazy glue.

 

[Tesla]

Well, I installed the heatsink.

The problem hot worse because it took longer for the processor to heat up. Remember, the video distortion got less the hotter it got.

ESR on the SMT caps on the logic board all checked out.

I removed the heatsink and closed it up. Gave it to my brother. He uses it as a second monitor (on a dual LCD setup). Just lets it warm up for 5-10 minutes and it looks pretty good.

My guess is the processor is bad or flakey.