T41 with static and yellow jumper wires?

[Bucksnort101]

Forgive me if this is redundant, but using the search engine just doesn't seem to find the anwers I'm looking for.
Have a couple T41 laptop boards I'm trying to troubleshoow. All of them have issues with the speaker giving off a static krackle when the volume is turned to max. One notch below max or muting and turning down the line-in option gets rid of it. Thought is was interference from the wireless antenna, but am not sure. Is there a more permanant fix for this issue?

Also notices some small yellow jumper wires on the top and bottom of the board. Any idea's what these repair were for? One set is on the bottom of the board near the USB ports, looks like a small semi-conductor was added as well.
One the top of the board there are some added capacitors and more yellow jumpers wires near Intel chip labeled RC82540EP which appears to be the NIC controller?
Just curious what these mods were added to repair if anyone knows? Looks like an in-house IBM repair job.

[poshgeordie]

The yellow wires are probably done by IBM and the board could well be an IBM refurbished board.

As to the crackle, is it present when operating just on battery with the AC adapter removed?

Is your AC adapter an official IBM one. Also does it have the three pin mains lead or a two pin?

Also what operating system are you using?

[Bucksnort101]

Yellow wire repairs are most definately an in house IBM repair, just curious if anyone knew what the mods were for.

Crackle occures with AC plugged in. Running Windows XP SP3 with all updates installed. Latest and greatest Audio drivers, BIOS, etc...
Seems to crackle most when the Wifi radio transmits looking for wireless networks, but that's not always the case. If I tap anywhere on the case or LCD plastics the crackle will stop. Once agin this only happens when the main volume is turned to max, one notch below it sounds fine, of if volume is left at MAX and the Line-in volume is turned way down. Which would tell me of interference from the MIC circuitry?
I've read of many other people having this problem as well. Just no definate cause?
AC adaptor is a IBM model, P/N = 08K8208.

[RealBlackStuff]

I don't know the cause, but if you know that full-blast produces crackle, why do you keep turning up the volume all the way?

[poshgeordie]

Crackle occures with AC plugged in. AC adaptor is a IBM model, P/N = 08K8208.

OK, putting the two phrases together. It does appear to be AC related. Checking the Charger type, from a couple of pictures I've (possibly) found of this part number, it has a two pin AC mains lead, ie one with no earth (ground) wire, and this lack of ground could be the issue.

I've had similar problems with no-ground AC adapters where the trackpad doesn't work unless I'm touching something metal on the laptop - admittedly the adapter was a very cheap Chinese made item which also caused massive interference on a nearby radio!