8400 won't boot, power, but no POST, diagnostic light code flashing yellow,Y,G,G

Question

My dimension 8400 suddenly stopped working, no recent hardware or software changes. When I went to use it, moving the mouse did not wake it up, and all read lights for the 2 dvd drives and the hard drive were blinking. And the DVD drives would not open. I rebooted and got the following code on the diagnostic lights

A=flashing yellow
b= yellow
c= green
d= green

The guide shows that YYGG indicates a memory problem, but I'm not sure if that includes the case where A is flashing yellow. Does it matter if the diagnostic lights are flashing and not steady colors?

I've removed and reseated the memory several times including trying several configurations, with the same results every time.

If I completely remove the memory I get a beep code ( I think it's 1,3,2 ). I need to check again what the diagnostic code is for that configuration.

I'm thinking the problem is memory or mother board. Unfortunately I don't have another machine in which I can test the memory.

Does anyone have any idea what the problem could be, and if the flashing yellow A diagnostic code light is significant.

thank you.

shesagordie · Answer

pstruhs

What is the reading of the power button LED, green, blinking green, solid amber, blinking amber?

Did you try installing the RAM, one module at a time, in different slot and restart the system after each install. The procedure are listed here,

http://support.dell.com/support/edocs/systems/dim8400/SM/adtshoot.htm#wp1052313

Check the motherboard for any leaking capacitors or with bulged tops.

Bev.

x_lab rat · Answer

Flashing yellow is not a legitimate A-B-C-D diagnostic code.  It means POST is encountering a problem early-on, and restarting.  If swapping memory and unplugging accessory cards makes no difference, the motherboard has failed.

ejn63 · Answer

Check the condition of the capacitors on the mainboard.

pstruhs · Answer

Thank you for your replies. Well when I unplug all the memory, I get a GYYY code ( no flashing ).

I've checked the capacitors, and I don't see any bulging or leakage ( but I admit I had a hard time spotting bad caps in the pics at badcaps.com ).

I've completely removed the motherboard now, and noticed one of the pins on teh 4 pin P2 connector is burnt.

I've called Dell to see if there is a recall on the PSU (A.02 ) or motherboard, but he did not understand I was trying to get recall information and wanted to send me to sales to buy the extended warranty ( I only had a year and it'll be 2 in January ).

I've read several posts about the blinking amber light on the front of the box, but mine was always green, and I haven't had intermittent shutdowns.

Looks like I'll be ordering a new PSU and a new motherboard tomorrow. I hope I don't end up replacing all teh parts in my machine to fix a loose cable :)

thanks again for your replies, after talking with official Dell support it's nice to talk to people with real world knowledge.

thanks.

DELL-Donald K · Answer

GYYY with no memory is a valid code

I would buy a single RAM module 1st before replacing the motherboard. If the system POSTs properly with new RAM, then RAM was the issue.

Also, when seating the RAM, disconnect all power from the system, press & hold the power button 10 seconds to discharge any stored power in the MB. THen make sure the locking levers are pushed out as far as they will go. Insert the RAM module in the slot & press down FIRMLY with both thumbs until the RAM is fully seated & the locking levers snap up into place on their own (DO not pull the levers up)

Test system again.

pstruhs · Answer

new update, I've replaced MB and PSU. Now the diagnostic code shows YYGY ( cpu error ) and beep codes are 4-4-4 ( also CPU error ) so it looks like the CPU needs to be replaced now. Really considering just parting this machine and building my own. I'm done with Dell. If anyone else is having power issues or an issue where the 8400 will not boot please read this and reply. This seems to be a common issue and since it involves compnents overheating and possibly burning, this is a safety issue.

Unfortunately Dell's tech support doesn't seem to take my concerns seriously, I'm hoping that a group of users with the same issue will prompt Dell to take some kind of action to protect their customers.

If anyone knows who I should contact about this safety issue please let me know.

thanks, Patrick

Locked Topics – Desktops General

8400 won't boot, power, but no POST, diagnostic light code flashing yellow,Y,G,G

Was this post helpful?