Dell GX 620 Motherboard Recap

[mockingbird]

Re: Dell GX 620 Motherboard Recap

Here you go:

[bigjess007]

Re: Dell GX 620 Motherboard Recap

Wow that's great stuff! Anyone know if the N275P and the H275P PSU's have the same caps by chance?

[c_hegge]

Re: Dell GX 620 Motherboard Recap

^
Unlikely. They are made by two different companies. The N275P is a Newton (subsidiary of Delta), while the H275P is made by Hipro.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

^
Unlikely. They are made by two different companies. The N275P is a Newton (subsidiary of Delta), while the H275P is made by Hipro.

Well, that sure sucks! I've just inspected my 2 GX620 SFF's, and one is a N275P and one is a H275P. Do you know if they are interchangeable? I'm guessing they are.

If it's confirmed they are, then I think I may just order a N275P from flebay and use all the info mockingbird posts and rebuild those 2 as I really don't want to have to desolder all the caps from the H275P to get the info (just got too much going on right now).

This may be a tad out of my league anyway cause if I have to desolder that daughtercard, I may be hesitant to try this.

Thanks!

[bigjess007]

Re: Dell GX 620 Motherboard Recap

I do have a kit for this board.... Only the MCZ series on it will ever give you any problems.

https://www.badcaps.net/store/produc...roducts_id=105

Topcat question on this, on the store page it doesn't say which caps these are going to be. Are they all Nichicon HZ's?

Thanks!

[c_hegge]

Re: Dell GX 620 Motherboard Recap

^
In all likelihood, yes (either that or HN, which will also be fine)

[mockingbird]

Re: Dell GX 620 Motherboard Recap

This may be a tad out of my league anyway cause if I have to desolder that daughtercard, I may be hesitant to try this.
Thanks!

19 pins in total for the daughtercard... You will need good, fluxed desoldering braid (0.050" width, might be able to use 0.075") for this ($3~ per 5 ft).

You really ought to get a better suited soldering iron for motherboards (You shouldn't be having a difficult time with that Hakko)... I recommend a certain brand of iron off eBay that cost only $6 and is 60w... It lasted me for a good few months and more than served its purpose.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

I posted in the other thread, but I think it's my technique.

I did some digging, and the N275P and H275P are interchangeable. This thread however caught my eye:

http://en.community.dell.com/support.../18058269.aspx

Seems the H275P is the response to lots of interference and other problems with the original N275P. Maybe that's why they switched manufacturers and changed the design.

I actually may be able to get a free H275P as well, so if I can, I'm going to grab it and have a stab at it. If not then I'll probably just order one off of flebay and go from there. I want to get one power supply successfully rebuilt before I take out the motherboard to recap it as I need to do it all at once and these 2 machines can't have alot of downtime.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

So I got a free H275P. Probably good that it's free, but that part is below

It's definitely laid out differently. No daughtercard, just a big heat sink running down the middle. Sure made for a pain in desoldering all the caps to get a list.




So I carefully desoldered all the caps so I could get their specs. However, this board has these copper colored "seats" or "sleeves" on the legs of the caps. I carefully heated and pulled all of the caps straight up, and still managed to pull out a few of these sleeves.

Here's the sleeve attached to a cap:



Here's a pic showing one of the sleeves I mistakenly yanked out (positive hole of C114):




There looks to still be traces in the hole, but I can't tell. What's these sleeves for (other than to show my continued lack of soldier abilities)?

And did I hose this board?

[mockingbird]

Re: Dell GX 620 Motherboard Recap

I'll let someone more knowledgeable give some more expert advice, but I think you may have ripped out a via. Very interesting to see them on a PSU PCB. You will probably have to find out where that hole connects to and run a jumper cable.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

I just looked up what VIA's are. I'm hosed, I ripped out I think 4. What the heck are they doing on this board? They are in every capacitor hole. Why would this psu have more than one layer? Is it because it doesn't have the daughtercard like the N275P and this was the solution to redesigning the board? I was super careful taking the capacitors straight out, but I'll confess I did have a hard time getting the solder to turn molten so the rocking and extra heat just ripped the VIA's out.

The N275P PSU doesn't have VIA's right?

[LLLlllou]

Re: Dell GX 620 Motherboard Recap

Here you go:

Thanks!

[mockingbird]

Re: Dell GX 620 Motherboard Recap

I just looked up what VIA's are. I'm hosed, I ripped out I think 4. What the heck are they doing on this board? They are in every capacitor hole. Why would this psu have more than one layer? Is it because it doesn't have the daughtercard like the N275P and this was the solution to redesigning the board? I was super careful taking the capacitors straight out, but I'll confess I did have a hard time getting the solder to turn molten so the rocking and extra heat just ripped the VIA's out.

The N275P PSU doesn't have VIA's right?

Don't fret, happened to me once before and ruined a perfectly good headphone amplifier that just needed a new output jack. In retrospect, I should have used a 60W iron... You should take my advice and get the $6 60W eBay iron for these sorts of jobs. Use your regular iron for straightforward stuff but the 60W for stubborn joints.

Good hypothesis, that's probably what it was, to integrate everything on one board, but that's not because they wanted to save money, what they did with the H275P cost a lot more than what would typically be done on a single sided board.

I wouldn't worry about the PSU interfering with your cellphone... Go ahead and re-cap the N275P.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

You should take my advice and get the $6 60W eBay iron for these sorts of jobs. Use your regular iron for straightforward stuff but the 60W for stubborn joints.

I'm game, got a specific auction? I see a ton of them when I search for 60W soldering irons. I do hope it's my technique though and not this brand new hakko station, that would seriously tick me off. Well that and those damn VIA's. I may get good at this yet.

[mockingbird]

Re: Dell GX 620 Motherboard Recap

Here you go:

http://cgi.ebay.com/140476241445

I really should pick another one up myself...

[bigjess007]

Re: Dell GX 620 Motherboard Recap

Here you go:

http://cgi.ebay.com/140476241445

I really should pick another one up myself...

Thanks! I ordered that iron and splurged on the $3 more for the epacket delivery so it's not February before it's delivered. Still will probably be January. I also ordered a N275P from flebay to go with the one I have and 2 sets of caps from digikey. I'll post back when I get all the stuff here.

If it's January before I return, a very Merry Christmas and a Happy New Year to everyone!

[bigjess007]

Re: Dell GX 620 Motherboard Recap

So even though I'm not going to be recapping the H275P because of the evil VIA's (I know my fault ) I thought I'd share my research in case someone else can find it useful.

Here's pics I took of the board:










Here's the diagram I made:




And here's a listing of all the info I gathered on the caps:

Cap	Brand	uf	Volt	D MM	H MM	Info on Sleeve:				Board
A	Ltec	10	50	5	8	ST105°C(M)	6116D
B	Teapo	22	50	5	12	SEK105°C(M)	05/06	A3 T2
C	Ltec	47	16	5	12	TK105°C(M)	6302D
D	Ltec	4.7	50	4	8	ST105°C(M)	6402D
E	Teapo	220	35	8	15	SC105°C(M)	03/06	A3 T3
F	Ltec	10	50	5	8	ST105°C(M)	6116D
G	Teapo	22	50	5	12	SEK105°C(M)	04/06	A3 T2
H	Teapo	22	50	5	12	SEK105°C(M)	04/06	A3 T2
I	Teapo	22	50	5	12	SEK105°C(M)	04/06	A3 T2
J	Ltec	1000	10	8	16	LXY105°C(M)	PET	6428D
K	?	470	10	8	12	KY	(M)105°C	6(7)	4B
L	?	1000	10	8	19	KY	(M)105°C	6(7)	3H
M	Ltec	2200	16	10	29	LZP105°C(M)	PET	6505D
N	Ltec	100	16	5	12	LZP105°C(M)	6505D
O	?	220	25	8	12	KZE	(M)105°C	6(7)	3B	C408
P	Ltec	1000	10	8	16	LXY105°C(M)	PET	6428D		C409
Q	Teapo	2200	10	10	20	SC105°C(M)	05/06	A3 T2		C417
R	Teapo	2200	10	10	20	SC105°C(M)	05/06	A3 T2		C419
S	Ltec	2200	16	10	29	LZP105°C(M)	PET	6505D		C407

If you take on a recapping, best of luck to ya!

[mockingbird]

Re: Dell GX 620 Motherboard Recap

Excellent job. Great pics and good documentation. An asset to anyone who needs to re-cap the H275P. Thanks for paying it forward.

[momaka]

Re: Dell GX 620 Motherboard Recap

Thanks for paying it forward.

Yes, thank you indeed

By the way, those caps with the "?" marks that have "KY" and "KZE" series are made by United Chemicon. They are excellent capacitors for power supplies and do not need to be replaced. Moreover, if you go to Mouser or Digikey, you will find that in most cases they are quite cheap. Most of the time, it's not a problem if you recap the PSU exclusively with United Chemicon KY and KZE, too.

[bigjess007]

Re: Dell GX 620 Motherboard Recap

Happy to pay it back and contribute any way I can. I learned a hard lesson on this board, so if someone else can learn from it, all the better.

Good to know on the KY's and KZE's too, thank you! Got a lot to learn on which are good and which aren't.