Hp Compaq dc7900 / HP 3032h / Electrolytic Capacitor / Motherboard Schematics - Page 1
Forum section: electronics / repair

author: xan
author_rank: Regular Contributor
timestamp: July 23, 2018, 08:04:49 pm
content: Hi Everyone,i need someone could help to find exactly electrolitics caps manufacturer and specification inside this motherboard HP 3032h.... Electrolytic specs are no more readablecan't believe... and schematics if can provide! Thank's for taking time.

author: xan
author_rank: Regular Contributor
timestamp: July 24, 2018, 09:58:26 pm
content: Here it is a foto of the motherboard taken from the web but the model it's the same... name "462431-001" (mmm... HWiNFo show me model HP "3032h" but anyway electrolytics color it's the same... ) anyone know how to get back information ? all light blue caps on RAM section and above PCI-E are destroyed unreadable...

author: helius
author_rank: Super Contributor
timestamp: July 24, 2018, 10:14:51 pm
content: If you have no other choice, simply using 22 uF 16V capacitors should be safe and may actually work.

author: xan
author_rank: Regular Contributor
timestamp: July 24, 2018, 10:25:56 pm
content: Do i have to choose some specific brand ? they looks Panasonic.... maybe... anyway why 22uF should be workin.. can you explain the functionality in specific ? Is there any way to get caps specifics from schematics (if i will find....) ??

author: helius
author_rank: Super Contributor
timestamp: July 24, 2018, 10:34:44 pm
content: The most important figure for bypass capacitors is not really capacitance, but ESR, voltage, and ripple current rating. That being said, 22 uF is squarely in the middle of typical capacitors used for bypass applications in computers. The most critical thing is not to use capacitors whose voltage rating is too low, as they will be damaged and could explode. The highest voltage found on most of a computer is 12V, which is present on PCIe, and the VRMs for the processor. The DRAM supply will have a lower voltage, but without more information I can't tell you what that is.

author: xan
author_rank: Regular Contributor
timestamp: July 24, 2018, 10:38:56 pm
content: Damn... for now thank you... and what about form factor specs ?

author: Rasz
author_rank: Super Contributor
timestamp: July 25, 2018, 12:18:54 am
content: the big ones might be 1000uF

author: xan
author_rank: Regular Contributor
timestamp: July 25, 2018, 11:30:37 am
content: i'm a little bit confused nowis there any motherboard manufacturer that write electrolytic specification on schematics or something like that ?

author: Rasz
author_rank: Super Contributor
timestamp: July 25, 2018, 01:06:25 pm
content: of course, but you are not likely to find original schematicpicture of partially(badly, still bulging caps) recapped board:https://ae01.alicdn.com/kf/HTB1BlxfbWagSKJjy0Fgq6ARqFXa6/Reboto-For-HP-DC7900-CMT-desktop-motherboard-Q45-460963-002-462431-001-DDR2-mainboard-100-tested.jpghttps://ae01.alicdn.com/kf/HTB14Q10bjuhSKJjSspjq6Ai8VXaC/Reboto-For-HP-DC7900-CMT-desktop-motherboard-Q45-460963-002-462431-001-DDR2-mainboard-100-tested.jpglooks like 3 different cap values, and most likely not all went bad, permanent marker all, measure and note voltage(on bare board without components), desolder and measure capacitance(even chinese $10 component tester will do).If I had to guess I would say you got 1000uf 6.3/16v, 470uf 6.3v, and the 4 biggest ones are 1000-3300uf 16v just going by the size.on the other hand its 775 platform, whole computer worth maybe $40 when 100% working, is it worth the trouble?

author: xan
author_rank: Regular Contributor
timestamp: July 25, 2018, 01:36:28 pm
content: of course i want to try recap the board! anyway with few new caps maybe i'll give more 10 year lifeAnother question... the board come with 1x4gb Micron Tech. 8htf12864ay-800g1 memory module do you think i could mix it with kingston hyperx 2x2gb khx6400d2k2 could you check for compatibility ?

author: xan
author_rank: Regular Contributor
timestamp: July 25, 2018, 04:50:19 pm
content: Quote from: Rasz on July 25, 2018, 01:06:25 pmi'll keep you updated! Maybe next week i'll have the mb on my lab for the inspection... it seems it's still working with so many bad bad caps !