The current on AE8 isn't going to be high enough for a little pitting to cause issues. Very little contact is enough for a sufficiently strong signal. Also the voltage on that signal pin is too low to cause audible arcing. Something else must be causing those noises. Same goes for VCC and VSS plus the pins are redundant so arcing shouldn't happen on those at all.

The memory controller isn't inside the CPU on LGA775 yet but still part of the northbridge meaning bad contact inside the CPU socket isn't likely to cause issues with indiviudal RAM slots on this board.

Sorry I don't have any new leads for troubleshooting this board but maybe it helps to know you've probably got to look for other defects. Good luck.

I’m going to assume you are not trying to use both DDR and DDR2 together, this board only lets you use one type of ram at a time.

Try to test other memory sticks.
If you are using DDR1 in special.
Plus make sure bios settings for memory are all default values before setting two sticks.

I am assuming you are not tempting to mix ddr and ddr2.

Yes, I am not trying to mix RAM types. I've tried one stick in each slot, and dual-channel configs, in case I needed a stick in one slot before a second would work in the other. And yes, I have tried different RAM, although moving a working stick from slot 1 to slot 2 doesn't POST. The DDR1 and DDR2 slots near the CPU work. The two I marked with red both do not POST if I put RAM in only them. In dual channel, the board/BIOS only reports the memory from the one working slot, whether I try DDR1 or DDR2. That second pair of slots simply doesn't register anything. I haven't seen any damaged on the board/traces, front or back.

The BIOS has been reset - I haven't had a battery installed since the old one was drained.

Still good questions though - you never know who you are dealing with on the internet, or what someone can overlook when going through mental checklists.

TrashPanda wrote on 2023-04-07, 05:43:

I’m going to assume you are not trying to use both DDR and DDR2 together, this board only lets you use one type of ram at a time.

I don't think that guy who managed to find pins and use microscope would put ddr1 and ddr2 together. However previous owner could do that.

To OP you could try another cpu as memory controller integrated in cpu and might be an issue

ciornyi wrote on 2023-04-07, 05:52:

TrashPanda wrote on 2023-04-07, 05:43:

I’m going to assume you are not trying to use both DDR and DDR2 together, this board only lets you use one type of ram at a time.

I don't think that guy who managed to find pins and use microscope would put ddr1 and ddr2 together. However previous owner could do that.

To OP you could try another cpu as memory controller integrated in cpu and might be an issue

Core2 doesn't have the memory controller in the CPU - if it did, surely we'd not be able to choose between both DDR1 and DDR2.

I fully plan to stick a different CPU in there just to do it, but my trays of socket 775 cpus are tucked away at the moment. I don't think the CPU itself is at fault for any of this though, and the Q6600 itself still looks perfect. Specifically I'm curious if the sounds around the CPU socket change or go away with an older Core2 Duo, or a Pentium D, are installed.

Okay, curiosity got the better of me and I dug out a couple trays of CPUs. With an E6300 in there, I haven't heard anymore of that cracking sound. Stuck an E7500 in there, same thing - no bad crackling noises. Neither of these trays have my 65nm quads in them.

Of course still only half of the memory slots work - one DDR1 or one DDR2.

Masejoer wrote on 2023-04-07, 07:04:

Okay, curiosity got the better of me and I dug out a couple trays of CPUs. With an E6300 in there, I haven't heard anymore of that cracking sound. Stuck an E7500 in there, same thing - no bad crackling noises. Neither of these trays have my 65nm quads in them.

Of course still only half of the memory slots work - one DDR1 or one DDR2.

Just regarding the noise: Is it possible the vent on the Q6600 had been blocked by thermal paste and thermal changes caused changes in pressure under the heatspreader creating those noises when air was being forced through the blockage?

Doornkaat wrote on 2023-04-07, 07:59:

Masejoer wrote on 2023-04-07, 07:04:

Okay, curiosity got the better of me and I dug out a couple trays of CPUs. With an E6300 in there, I haven't heard anymore of that cracking sound. Stuck an E7500 in there, same thing - no bad crackling noises. Neither of these trays have my 65nm quads in them.

Of course still only half of the memory slots work - one DDR1 or one DDR2.

Just regarding the noise: Is it possible the vent on the Q6600 had been blocked by thermal paste and thermal changes caused changes in pressure under the heatspreader creating those noises when air was being forced through the blockage?

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no.

It's noise that I've rarely heard in the past, when something was electrically shorting/arcing, but it's the sound I'd point to. It's not the fan/bearings (doesn't sound the same, and I've tested without fan powered - first check I did). I'd like to try another q6600 in there, but I do suspect that the noise will return. I'm just not hearing it with the two dual cores I've installed for testing.

The only visible sign of anything I've seen is that CPU pin, and the discoloration of the surrounding pins. I've tried cleaning the board, rinse, dry to make sure no debris is shorting anything, but it hasn't helped. Thermal imaging with macro lens also showed nothing out of the ordinary, but it's also something that could uncover a shorting/failing circuit.

Right now I just have memtest running on the e6300 with a single stick of DDR2, but I don't expect any errors there. A few passes without errors yet. Just checking the working memory slots/Northbridge.

Masejoer wrote on 2023-04-07, 08:22:

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no. […]
Show full quote

Doornkaat wrote on 2023-04-07, 07:59:

Masejoer wrote on 2023-04-07, 07:04:

Okay, curiosity got the better of me and I dug out a couple trays of CPUs. With an E6300 in there, I haven't heard anymore of that cracking sound. Stuck an E7500 in there, same thing - no bad crackling noises. Neither of these trays have my 65nm quads in them.

Of course still only half of the memory slots work - one DDR1 or one DDR2.

Just regarding the noise: Is it possible the vent on the Q6600 had been blocked by thermal paste and thermal changes caused changes in pressure under the heatspreader creating those noises when air was being forced through the blockage?

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no.

It's noise that I've rarely heard in the past, when something was electrically shorting/arcing, but it's the sound I'd point to. It's not the fan/bearings (doesn't sound the same, and I've tested without fan powered - first check I did). I'd like to try another q6600 in there, but I do suspect that the noise will return. I'm just not hearing it with the two dual cores I've installed for testing.

The only visible sign of anything I've seen is that CPU pin, and the discoloration of the surrounding pins. I've tried cleaning the board, rinse, dry to make sure no debris is shorting anything, but it hasn't helped. Thermal imaging with macro lens also showed nothing out of the ordinary, but it's also something that could uncover a shorting/failing circuit.

Right now I just have memtest running on the e6300 with a single stick of DDR2, but I don't expect any errors there. A few passes without errors yet. Just checking the working memory slots/Northbridge.

Q6600 is more power demanding cpu so noise you heard easily could be bad conductivity on damaged pins. Also this board is know how weak vrm is. As for memory it might be damaged north bridge since memory controller built in.

Masejoer wrote on 2023-04-07, 08:22:

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no. […]
Show full quote

Doornkaat wrote on 2023-04-07, 07:59:

Masejoer wrote on 2023-04-07, 07:04:

Okay, curiosity got the better of me and I dug out a couple trays of CPUs. With an E6300 in there, I haven't heard anymore of that cracking sound. Stuck an E7500 in there, same thing - no bad crackling noises. Neither of these trays have my 65nm quads in them.

Of course still only half of the memory slots work - one DDR1 or one DDR2.

Just regarding the noise: Is it possible the vent on the Q6600 had been blocked by thermal paste and thermal changes caused changes in pressure under the heatspreader creating those noises when air was being forced through the blockage?

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no.

It's noise that I've rarely heard in the past, when something was electrically shorting/arcing, but it's the sound I'd point to. It's not the fan/bearings (doesn't sound the same, and I've tested without fan powered - first check I did). I'd like to try another q6600 in there, but I do suspect that the noise will return. I'm just not hearing it with the two dual cores I've installed for testing.

The only visible sign of anything I've seen is that CPU pin, and the discoloration of the surrounding pins. I've tried cleaning the board, rinse, dry to make sure no debris is shorting anything, but it hasn't helped. Thermal imaging with macro lens also showed nothing out of the ordinary, but it's also something that could uncover a shorting/failing circuit.

Right now I just have memtest running on the e6300 with a single stick of DDR2, but I don't expect any errors there. A few passes without errors yet. Just checking the working memory slots/Northbridge.

Im guessing there might be some cracked BGA balls on the northbridge, not sure how difficult it would be to check continuity between the Northbridge and the ram slots that are not working. You might need to source a pinout for the Northbridge, another stab in the dark would be to reflow the Northbridge die and see if the dead ram slots start working again.

Masejoer wrote on 2023-04-07, 08:22:

Considering that the Core2 chips don't have such an alignment/"vent" hole, I'd say no.

It's noise that I've rarely heard in the past, when something was electrically shorting/arcing, but it's the sound I'd point to. It's not the fan/bearings (doesn't sound the same, and I've tested without fan powered - first check I did). I'd like to try another q6600 in there, but I do suspect that the noise will return. I'm just not hearing it with the two dual cores I've installed for testing.

The only visible sign of anything I've seen is that CPU pin, and the discoloration of the surrounding pins. I've tried cleaning the board, rinse, dry to make sure no debris is shorting anything, but it hasn't helped. Thermal imaging with macro lens also showed nothing out of the ordinary, but it's also something that could uncover a shorting/failing circuit.

The recessed area in the IHS's edge is not glued to the substrate. This gap prevents pressure from building between IHS and substrate. Try for yourself: you can push a bit of paper in there with no problem.

Discoloration and pitting may very well be caused chemically. Nobody can tell the history of this board. Audible arcing isn't electrically plausible here imho. If it were that bad the PC would definitely crash.

I'm happy to be proven wrong on any of those points.

I have 3 of these boards and all of them have cracked solder joints under the north bridge chip duo to idiotic placement of atx connector near the chip.
one of them has the same issue as yours and second ram slot don't work but if you apply pressure to the chip's pcb with your finger, it works.
one easy fix is to clean under the chip with alcohol then cut 4 small thermal pads like 3mmx3mm and put it at 4 corner of the chip's pcb.
the thermal pads must be thicker than the chip's core then tight the heatsink with plastic screws.
or just reflow the chip if you have the equipments.

Karbist wrote on 2023-04-07, 15:55:

I have 3 of these boards and all of them have cracked solder joints under the north bridge chip duo to idiotic placement of atx […]
Show full quote

I have 3 of these boards and all of them have cracked solder joints under the north bridge chip duo to idiotic placement of atx connector near the chip.
one of them has the same issue as yours and second ram slot don't work but if you apply pressure to the chip's pcb with your finger, it works.
one easy fix is to clean under the chip with alcohol then cut 4 small thermal pads like 3mmx3mm and put it at 4 corner of the chip's pcb.
the thermal pads must be thicker than the chip's core then tight the heatsink with plastic screws.
or just reflow the chip if you have the equipments.

Great, I'll check it out/try pressure on the NB. Yeah, if that's the case then a proper fix is a reball which I can't do/not comfortable trying, but I can try a reflow at some point.

The logic makes sense regarding the ATX placement.

Karbist wrote on 2023-04-07, 15:55:

I have 3 of these boards and all of them have cracked solder joints under the north bridge chip duo to idiotic placement of atx connector near the chip.

Sure enough, the system POSTs with memory in the second slots with downward pressure on the Northbridge. Very good to know. I didn't know that this board model has this known issue, otherwise I wouldn't have seeked one out - not worth AGP on 775 if the board itself is untrustworthy. I've been fine with a couple other Asrock boards over the last 15 years in primary systems, so I don't dislike the brand itself.