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HP Pavilion a1737c - Non-Standard PSU/MoBo - How to Diagnose?

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Randyman...

Randyman...

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Joined
May 8, 2004
Edit - I'm a big dummy :)

EDIT 09-12-2009 @ 2:12AM - This was an error on my part - The HP Pavilion a1737c does indeed use a standard 24-Pin ATX PSU. See This Post Below for my explanation...

As you were... :eek:


Original Post:

So, I'm trying to diagnose/repair my buddy's HP Pavilion a1737c desktop. It currently won't power on or get into POST. The stupid Power Supply (PSU) uses a non-standard 24-pin connector - so I have no way to swap PSU's, or to try this PSU in a different system. I pulled the CMOS battery, still no go. It has Onboard Video - so it's not a faulty video card, and I unplugged all peripheral drives - nothing works...

Here is what I have observed thus far:

The PSU has a green LED on the back. If the PSU's 24-pin connector is plugged into the MoBo, the PSU's green LED is dimly lit (almost can't see it). If I unplug the PSU from the MoBo, the green LED illuminates at full brightness. All voltages test good by manually turning on the PSU with the jumper trick - but this is a "no-load" condition - so the results aren't conclusive - and I don't have any way of "loading" all of the rails to test properly.

Do you think this would point to a faulty PSU that can't provide any current to speak of - causing the green LED to dim (but can supply the correct voltage w/o any current into a multimeter) - OR - that the MoBo is fried and shunting/shorting the PSU?

Thanks for any pointers since my usual component swapping methods won't work with this proprietary HP B.S. :mad:
 
Last edited:
I'm thinking psu but without another good one or another mobo to swap with, I don't know how else to tell. I hear ya on the proprietary crap too. I'm getting ready to gut my bench computer, a HP d4650e, with a new cheap mobo and a spare psu that I have. It's a good thing I can run Windows 7 RC until next year too. Maybe you could do the same with your buddy's PC?
 
The psu uses a non-standard connector so any spare psu that he has access to won't fit the motherboard, and he can't use the psu on any other motherboard because of the funky connector.
 
From what I can see it looks like a normal power supply. What's different? Why won't it plug in? I've replaced several of this same style of HP case and they have all been standard ATX and HP uses Asus boards.
 
Thanks for all of the input. This one certainly does not use a standard 24-pin connector. Some of the wires are reversed, and the molex shapes are re-arranged so it is impossible to plug in a standard PSU's 24-pin connector (it physically won't fit - and even if it did, some of the wires are reversed and wouild likely fry the MoBo/PSU or both). The PSU even has a "HP" prefix on the part # :mad: THis is a 2006 HP PC...

Swapping MoBo's and PSU's with "standard" parts would only be an option if my friend wants to buy both parts - as I need to hang on to my few spares for my own "backup purposes" ;) . I'd bet a basic MoBo and PSU would be cheaper or about the same cost as the specific HP MoBo or HP PSU by itself.

I'll chew on this for a while, and give my buddy the options. I'd love any further input on how to test the current system further w/o having access to any other proprietary PSU/MoBo 24-pin type connectors...

Rock and roll :cool:
 
Last edited:
Check the dark green wire on the mobo power connector's voltage.
That should, if i remember correctly, be the one that you can jump to ground to turn the PSU on.
Google it (heh) and if it is, jump it to ground briefly and see if the PSU turns on.
If it does, the mobo is dead.
If it doesn't, the PSU is dead.

Really, unless you want to buy new proprietary parts from HP the mobo/PSU combo is history and it's time to build a new box and slap the old drives in.



EDIT:
My money is on PSU failure killing the mobo, but that may just be my dim view of HP and proprietary stuff showing.
 
I already powered on the PSU by shorting the Green to Ground. All of the voltages test good as mentioned above, but this is with a "no-load" condition (nothing is drawing any current).

I'm searching, and I'm not seeing anything about proprietary 24-Pin ATX connectors for this particular PC - But I know the "Spare" PSU I have would not fit into the HP MoBo. I'll double check this against another ATX PSU when I get home - Hopefully this isn't "user error" on my part (wouldn't be the first time, but I swear my "Extra PSU" is a standard ATX PSU - so I'm a bit confused ATM).

I'll report back around 1AM when I get home - hopefully w/o egg on my face :)
 
This is odd, as I know I pulled my "Spare PSU" from an ATX system. I'll verify this when I get home @ 1AM. I REALLY hope I was mistaken :eek:

:cool:
 
Hey that's the exact board that I have and I'm replacing this weekend. It's just a standard mATX 24 pin connector.
 
Well golly wally. I have no idea how I ended up with a "Non-Standard Spare ATX PSU" then (if the MoBo is standard, then my "Spare PSU" must be non-standard). I'm very confused at this point.

Thanks for the corrections and confirmation that I'm a big dummy :p
 
I know I tried to plug it in every which way - and the wire arrangement was also different.

I guess my "Spare PSU" MUST be the "Non-Standard" part - and the HP is "Standard". Again - this is odd, as I've never swapped PSU's in a "non-standard PC" to have a non-standard spare PSU laying around my parts collection. I'm still very confused on where my extra PSU came from. I could swear I pulled it from an ATX system :confused:

I'll report back @ 1AM as I wipe the egg off my face :)
 
:beer: You were right.

I pulled a regular Sparkle 400Watt ATX PSU from one of my lesser-used PC's, and it fit the HP like a glove. I have absolutely NO CLUE where my "Extra-PSU" came from, but the Extra PSU I was attemting to use had the non-standard 24-Pin plug. I swear I pulled it from a regular ATX system and I don't have the standard 24-Pin wiring configuration memorized - thus my confusion (my memory is going already). Go figure :eek:

Anyways, the problem was instantly solved when I replaced the PSU - the computer runs fine now (well, as fine as a bloated aging Vista Home Premium install can run with 1GB of RAM :eek: ). I actually slipped in 2GB of RAM since I had some laying around and I can't stand to see people suffer like that :p - but I'll have to charge him $40 for the descent Sparkle PSU I tossed in there ;)

Rock and roll...

:cool:
 
You probably pulled it out of an old system that you just don't remember doing. I have a drawer full of old psu's that I can't remember where I got them all from and don't know why I'm keeping them. Am I really going to use a 300 watt psu???:confused:
 
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