Re: LA-9104P 7 beeps no video (inspiron 3521)
In fact the only missing voltages are +VCC_CORE and VCC_GFXCORE_AXG i no longer have the board as i returned it to it's owner, the low current i think it's caused becouse the chips were in reset state, thaks everyone for the help.
cpt.charlie
Badcaps Veteran
Last Activity: 11-11-2023, 08:53 AM
Joined: 09-11-2013
Location: Torrelavega
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Re: LA-9104P 7 beeps no video (inspiron 3521)
Hi mcplslg123, the current consuption with ram (and no fan) is 122mA with peaks of 135mA, without ram it remains at 119mA, pin 30 on both cases is 0.34V, i've checked QC2 and all i get is 3.3v on gate and 0V on drain and source, however none of these lines are shorted to ground, RC108 and RC110 are 1K and i have the expected 1.5v at RC108.Leave a comment:
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Re: LA-9104P 7 beeps no video (inspiron 3521)
I have tested 2 bios with the same result, unfortunately i can't flash the EC.Leave a comment:
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Re: LA-9104P 7 beeps no video (inspiron 3521)
Hi, i've checked all the power supplies and except PU700 all PSU are working fine.
PU200 (3.3v and 5v) OK --> Pgood pin 23 =5V
PU300 (1.5v and 0.75v) OK --> Pgood pin 10 =0V not connected
PU400 (1.8v) OK --> Pgood pin 4 =0.5V not connected
PU500 (1.05v) OK --> Pgood pin 1 =3.3V
PU600 (0.9v) OK --> Pgood pin 4 =3.3V
UZ1 also works fine....Leave a comment:
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Re: LA-9104P 7 beeps no video (inspiron 3521)
Hi nom2, in my case 1.5v is present and the mosfet works just fine, my problem seems to be a bit more tricky....Leave a comment:
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LA-9104P 7 beeps no video (inspiron 3521)
Hi folks, happy new year!
I'm trying to fix this dell that turns on but it gives no display, just 7 beeps (CPU related code), visual inspection didn't reveal anything significant, after some measures i discovered that the board is generating all voltages except +VCC_CORE and VCC_GFXCORE_AXG this voltages are generated by the same IC PU700 checked the IC and VR_ON is high and the chip gets proper 5V power.
I thought the chip was defective and replaced it, to my surprise i got the same result with the new chip oops! checked the mosfets and seem OK, the resistance on... -
Re: Canon K30321 / Delta EADP-24NP
Recently i had to fix this PSU with the same syptoms as the OP described, in my case the main cap was leaky, fuse was gone and 3 diodes of the bridgde recifier were damaged (2 shorted and the third open), main mosfet was Drain-Source shorted and ZD33 was shorted too, i've replaced it with a 5.1v zener based on it's markigs, also D5 had failed open, after all these replacements the PSU seems to work just fine so far.Leave a comment:
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Re: space for another DDR slot... put one there?
The best option would be a solder bath, but that's an unusual tool
[url]https://www.youtube.com/watch?v=mfT3SBcr9a0[/url]
If you can remove the plastic socket without damage the board it should be easy to remove the pins and clean the holes
[URL]https://www.youtube.com/watch?v=G__Ry0-wXjA[/URL]
Or maybe a big preheater and a hot air station but this would likely damage nearby plastic components.Re: space for another DDR slot... pu...he best optionLeave a comment:
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Re: space for another DDR slot... put one there?
Likely you will need to add some extra components like the resistors.Leave a comment:
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Re: How can I desolder chock coil in PGA370 socket mainboard
Ooops, i didn't check the pictures looking for jumpers so common back in the day....Leave a comment:
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Re: SIS 496 PCI Motherboard - working but only with graphics card in third PCI slot
Maybe you have a bad PATA cable, those used to be a bit problematic specially if you are using the original ones!Leave a comment:
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Re: How can I desolder chock coil in PGA370 socket mainboard
Maybe a stupid question, but have you checked the jumper configuration in the mainboard (CPU multiplier, FSB, Vcore....)Leave a comment:
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Re: AMD 3870 VRAM problem?
Today i had some time and i decided to reflow the card using the attached profile in my DIY reballing machine but unfortunately it didn't have any affect at all, it's a pitty, i guess at least i have a nice paperweight
...
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Re: AMD 3870 VRAM problem?
Here is an example of what i said about the memory, it seems to be damaged due high working temperatures in this case, but no visual damages or shortcircuit detected.
[url]https://www.youtube.com/watch?v=a5sw61l1eJk[/url]Re: AMD 3870 VRAM problem?<br /> <b...w61l1eJk[/url]Leave a comment:
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Re: AMD 3870 VRAM problem?
About the flux i know it won't affect to the internal micro BGA, but remember, i was reflowing the VRAM chips.
This made me think about a crazy idea to test one day, maybe remove a bit of the underfill in oposite sides as it just cover the edges, inject some liquid flux and reflow the core. I guess it uses higher temperature melting point alloy so maybe 250/260ºC needed, if it works reseal the chip with epoxy, the problem of this plan is that underfill is quite resistant and very hard to remove without damages on the core or substrate,...Leave a comment:
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Re: AMD 3870 VRAM problem?
Interestingly i have another 3870 that came with the now damaged unit, but the working one is pasively cooled, in fact i expected this unit to fail as i expected higher working temperatures on a pasive VGA however it seems to be working just fine, i should replace the thermal paste, but after what happened to the first unit it's better to not mess with "temperamental" GPU chips.
I also have a 7900gt with the same issue, maybe it needs a reflow too, these chips were affected by the bump issue too.Last edited by cpt.charlie; 06-08-2020, 03:35 PM.Leave a comment:
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Re: AMD 3870 VRAM problem?
Thanks Momaka, i completely agree about the high working temperatures of the 3000 and 4000 series of ATI, during the futurmark test i saw this card reaching nearly 90ºC quite impresive.
With regards the flux, i use it to prevent and remove oxidation if possible and at the same time it makes the solder to flow easily as it transfers some heat. I had some hope it was related to the VRAM as a faulty GPU core is a dead card (yep, these chips were affected by the bumps problems), i got some info about artifacts at this link:
[url]http://www.playtool.com/pages/artifacts/artifacts.html[/url]...Leave a comment:
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AMD 3870 VRAM problem?
Some moths ago i bought an old radeon 3870 for my retro pc project, i tested it for 20 minutes with futurmark and everything was OK so i dedided to put it in storage while i was gathering the rest of the components (dual core 939 platform).
This week i finally got the rest of the parts and started to assemble the pc, but first i had to do a proper cleaning of the card and new thermal paste had to be applied, after assembling it, the card seemed to work fine but ramdomly after maybe 7-10 minutes artifacts appeared on screen (some vertical lines but no BSOD or crashes) if i move a window... -
Re: Intel 760p SSD SSDPEKKW256G8XT
Looks like a dc-dc converter, can you post what's written on the chip?Leave a comment:
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Re: Modifying Laptop PSU 19.5V to 24.0V
One optocoupler is for controlling the voltage, and maybe the other is used for overcurrent protection (the trimpot is likely part of the OCP circuit), if you need to locate the voltage divider, start looking for the voltage reference (normally TL341) in a sot23 package.Leave a comment:
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