Rare YLOD symptoms in PS3 help?

[xboxgt12]

I use it horizontally. It does turn off when cold. For example, I haven't used it for 24hrs, then right now I decided to use it,

1. turned on and stayed on for 7 secs, it beeps 3 times the shows the yellow light then flashes red until I touch the power button again.
2. turned on for the second time and only lasted 18 secs, it beeps 3 times the shows the yellow light then flashes red until I touch the power button again.
3. turned on for the third time and only lasted 7 secs, it beeps 3 times the shows the yellow light then flashes red until I touch the power button again.
4. turned on for the fourth time and this time it stays on forever If i dont try to run games.

After trying to run a game it turns off... it beeps 3 times the shows the yellow light then flashes red until I touch the power button again. I have to do those 4 steps fast so the console can get a little warmup because if try to turn it on leaving minutes pass by between power on's the console will keep going to step 1 as stated above. Its like the console needs a warmup to work, but then fails to load games. The console is in a very ventilated area with 2 12v fans attached to it.

It has 3.55CFW installed.

UPDATE: I did the reflow on it and it did not get better nor worse, its just doing the same thing as explained above. what other things could cause this?

The temperatures of the cpu and rsx gathered by multiman are the following,

Cpu=66C
RSX=66C

After the fourth time of turning it on, I played a 3d bluray movie and it never shutdown, but it will shutdown with any game.

[Anger007]

definitely sounds like a cold solder joint, which is a solder joint that isnt properly connected when cold but when heated up connects and works however when stressed it breaks again. one thing i have to add - i tried adding a fan to my setup and it blew the hot air from the gpu onto the cpu causing it to ylod very quickly so more fans is not always a good thing - in fact the extra fan might be taking too much power from the psu causing the system to ylod. i would remove all extra fans and perform a more thorough reflow on the gpu mostly but do the cpu as well.

[niwakun]

sounds like a busted Power Supply for me.

[xboxgt12]

It make sense... but the fans are drawing power from an external ac power supply.

sounds like a busted Power Supply for me.

How can I test it with a multimeter?

[Anger007]

its tricky, in fact its not worth doing you really need an oscilloscope. its far easier to borrow a psu from another ps3 system of the same model or even buy one if you can afford it but beware it may not be the psu. honestly i would just sell it for spares and buy a good used one, because this kind of fault is so hard to track down without a supply of parts and some health knowledge of the ps3 electrical system as well.
i still go with stopping the extra fans and see how the machine responds because if its different then it will be easier to find the problem.

[niwakun]

How can I test it with a multimeter?

measure the amperage, if it drops to reasonable level, probably way too low from 18amps (yeah, most psu have 20-38amps) the PS3 goes red blinking due to lack of power.

note that PS3 games does take extra PSU power, in my test, from early fat models, XMB occurs at 23amps and in-game it hits 25-27amps. PS2 games can hit 30amps or more. So yeah, that's it.

i only tested this with CECHA and CECHC models, later models have different power amperage requirements.

[xboxgt12]

It really sounds like an interest point of view, but can this lack of power cause the ps3 to shutdown 3-4 times then start normally working?

Now the cold solder joint theory sounds like a more realistic problem. How many seconds on each chip should I apply heat with the gun, since 1 reflow has been done.

[Blade86]

On my NAND with 350°C heatgun:

15sec rotating in a circle on each of the 4 areas on the mainboard after cleaning it from all old "thermal paste" then AT LEAST 15min waiting for cooling down WITHOUT MOVING the board. Then same procedure on the other side of the board WITH COOLING-DOWN-TIME (at least 15min)...

[Anger007]

my advice is get some liquid flux and use it before doing the reflow as the solder is probably dried out by now.

my heat gun is unbranded so i dont know what temp it uses but i use flux as well so my heat time is 35 seconds per chip per side of the board.
i use less time on the rear side of the board and i usually dont bother with it even tho your supposed to.

Be aware i have tested the time it takes me with my heatgun and if you use my time without checking you could damage your ps3 permanently.

i suspect that even 35 seconds for me isnt enough because i have a ps3 which definitely has a broken solder joint and 35 seconds isnt enough to fix it.
the chip could be permanently buggered however it may be that the solder isnt getting enough heat.

btw best way to tell how long to use for the heat gun you have is use an old circuit board and use the heat gun until the solder just melts then add a few seconds when your doing the fix to your ps3 (because the chips in the ps3 have heatspreaders on them).

also i will reiterate whats been said - do NOT move the board or even bump it in any way as one single dislodged component means you could have a brick (unless your very very lucky).

[xboxgt12]

Ok guys, the second reflow was made but nothing changed at all, it keeps doing the same thing. I gave 30 secs on each chip and the rams too. I'm about to give up.

I even replaced the hdd.
2 reflows done.
New Artic silver 5 thermal paste.
Started ps3 without bluray drive, without the little board that recognizes the controller. bent the 2 metal clamps for more pressure.

All of that with no good results.

Can it really be the power supply? How do I measure it, with ps3 on or off? Where do I stick multimeter's probes to? I will be checking the amp right?