Projector repair and bad HP supercapacitors (PWJ105)

[@criteriumprovidus4360]

I don't usually take time to write comments on KZbin, but your video has lot of good info that is very difficult to find. You explained in details exactly what I was trying to understand about why HP and others started using Super-Caps instead of batteries. I truly appreciate your inside on this. Keep up the good work.

[@PlaywithJunk]

Supercaps do have a longer lifetime than most batteries but it is important to use good quality caps and also treat them well. If used wrong, they can be worse than all previous methods. Supercaps are easier to integrate in a circuit as long as you take care of the maximum voltage they can survive. And they are not such a fire hazard than Lithium batteries. Interestingly HP went back to batteries but they no longer use NiCd cells, they use Lithium cells now.

[@MrDubje]

Not sure what HP was thinking here... Kinda weird to just rely on the quality of the caps themselves. Nice ones too, except for the brand, 34F? Geez. I wonder if they couldn't get high capacity ones with a voltage rating of 5,5V, but those likely have a different form-factor. Resistors are probably a bad idea if they just could get the timing right with the capacity on hand. You would have to factor in the dissipation in the resistors as well, which would limit the time the voltage on the caps would be high enough for the circuit to operate without corrupting stuff. A too high value of resistor would have the same effect of having none present at all. It wouldn't balance as it won't pass the current in case 1 of the caps failed. So zeners would be the best option, but even then there are 2 problems: I imagine, with a system (battery-less solution) like this, you want the caps to charge up quite fast when the power is restored to keep the circuit alive when another brownout occurs or something like that. Caps like this take quite a bit of current to charge them moderately quick. That means you need a good amount of charge current. in case a cap fails, the charge current passes through the zener. Zeners are only capable of handling so much as a few mA, as far as I know. Not Amps! So they would fry over time when the failure becomes worse.The second problem I can see, is that you have to find a suitable zenervoltage, and probably select them as well, as there can be small differences between them, but I'm not sure.

[@uwezimmermann5427]

the faulty capacitor does not have to fail in short-circuit. It is enough if the capacities are different for the capacitive divider to get out of balance. The balancing resistors or zener diodes would help in this case as well.

[@ServiceComputers]

Hmmmm.... I smell a business opportunity with those supercaps.... Replace bad caps with high quality caps, add protection parts & extra profit.

[@TechCellfish]

So true about the HP supercaps. I have changed a lot of them in our Gen8 blades..

[@PlaywithJunk]

Now you know why.... :-)

[@simontay4851]

Make sure you add the missing balancing resistors/zeners to the new ones.

[@PlaywithJunk]

We install the new ones as they come from HP on the Gen8. The Gen9 does not use supercaps anymore but Li-Ion batteries, so the problem hs gone anyway. And most of the caps are working perfectly for years. BTW the Gen9 batteries are failing too but for other reasons :-)

[@johnsenchakinternetnetwork2025]

It's freak'in hot here in Florida USA Do you have flux capacitors in Switzerland ? I heard they put them in BMW's ( Beamers) in Germany Love the church bells ! The capacitor got impregnated by the male connector LOL

[@Chriss120]

"Projector" ist der richtige begriff. habe ich oft genug von der englisch Lehrkraft gehört.

[@PlaywithJunk]

Und alle werden sich fragen "what the heck is a beamer?" Uebrigens BMW's werden bei den Amis auch oft "beamer" genannt.... BEE EMM dobbelwiu :-)

[@SproutyPottedPlant]

Wouldn't want to turn off the fans or air conditioning in this weather! 🌞 Even here in UK it is nice and hot but humid too and not enough swimming pools.

[@AltMarc]

In his/my country, private AirC is not a thing, we would be lucky to use it more than one or two month per year… Trapping cold night air for the day, works.

[@PlaywithJunk]

It works in a solid built house. I was in a hotel in California and I thought I will switch the AC off during the day when I'm not there.... saving energy... When I came back in the early evening it was about 50 degree in that room. Then I examined the walls and found that they are thin like cardboard. No wonder that exery US house needs an AC. They build houses with wooden frames and plywood. Our garden shed is built better than that.

[@simontay4851]

Yeah, US houses are built very cheap and poorly from thin plywood and cardboard/plasterboard with no thermal insulation or structural strength and are easily destroyed by high wind. . In the UK and mainland EU, houses are built properly with solid stone or brick outer walls, internal non supporting dividing walls may still be plasterboard in newer houses though.

[@simontay4851]

Yes, my shed is built better too.

[@prinsonpjohnson9978]

Hai I have the same projector xd1150 but last time I start the projector then kinda smoke .Is that same problem of capacitor

[@PlaywithJunk]

possible. But there are many parts inside that can smoke.... Try to find where the smoke came from.

[@gglovato]

What are Dell's issue with their supercaps? I wasn't aware if that

[@PlaywithJunk]

Watch this video kzbin.info?o=U&video_id=toEXLx1E48I They have badly leaking supercaps that destroy the "battery" module with electrolyte. And Dell does not sell the module, you can only buy the entire controller.

[@victorwong3311]

I thought he had a BMW motorcycle he was going to fix with supercapacitors. A little disappointed. :)

[@Benjamin_S.]

*Projector - Beamer is a pseudo-Anglicism, same as Handy (mobile phone)

[@PlaywithJunk]

may be.... but it's time for the english speaking people to learn a better and shorter name :-)

[@mikeselectricstuff]

If you say Beamer in the UK at least, few people will know what you're talking about.

[@seanharris6982]

Yeah, its called a projector. Maybe instead of Fussgängerübergang, try crosswalk :D

[@PlaywithJunk]

I will change the title.... ;-)

[@PlaywithJunk]

Nobody calls that "Fussgängerübergang" in real life, maybe some officials. Although "Zebrastreifen" is not much shorter. Anyway we don't say "Fahrstuhl" anymore but Lift.

[@ChipGuy]

That you can even work AND make a video in 30°C. Wow, thanks. I can't do anything in 28°C without literally melting away. OK, coding C in relax position on the couch is just doable. But that's it.

[@simontay4851]

I can't either. I don't want to do anything except lye in the bath in cold water in 30C

[@PlaywithJunk]

I prefer lying on a deckchair in the shadow of a huge tree, having a cold beer next to me, some chips and a good book.

[@markg735]

I'm from Florida and it's not that hot outside (well, maybe it gets to 35 during mid-day). That sucks.

[@raderadovanovic1617]

I recently bought an acer acer xd1170d similar to yours and I connected it to a PC with a DVI cable. A picture was projected on the wall, but the problem is that when I open KZbin or any other application, the whole picture does not appear, but only a small window at the bottom of the screen. I don't know what the problem is. I tried to reduce the resolution on the PC to 800x600. is on the projector, but nothing. I also tried the screen settings in the control panel (monitor 1, monitor 2, etc.) but nothing changed. The projector is simply unusable for me because it cannot read the full image on the screen, i.e. the wall. Do you perhaps know what could be the problem - is there something wrong with the projector or do you need to adjust something on the computer? thank you

[@PlaywithJunk]

If I understand you right, the projector does work properly with windows only but it doesn't work when you open something? Hmmm what does the "small window" show? An error message or the contents of the application? I would say that the resolution or the frame rate is incompatible with your projector. If it is only capable of displaying 50 FPS and your computer outputs 60 that may cause that issue. Does the projector work with another video source like a DVD player? You may answer to [e-mail]...

[@raderadovanovic1617]

@@PlaywithJunk I tried again last night but I connected the projector to an old model laptop (dual core with 2gb ram) and everything worked normally! I guess you're right, the problem is probably my PC's compatibility. The projector is an old model from 2005, maybe like the laptop, and the PC is newer (i5 with 8gb ram). When it is connected to the PC - only the desktop image with icons is displayed and when I click on any icon - nothing happens. I put the cursor on the icon on the taskbar .then that small window appears where I see that the application is open but it won't show me the full screen. I probably need to make additional settings on the control panel and the graphics card to match the compatibility of the PC and the projector (resolution, frame rate, scale and other). In any case, thank you for your answer... For now, I will use the projector via my laptop

[@PlaywithJunk]

@@raderadovanovic1617 OK, I'm glad to be able to help 🙂 Funny coincidence is that last Friday a colleague at work came to me with a simiar problem. It was not a projector but a long line VGA video tranmitting device. He also got the whole image but extremely squeezed to the left of the screen. I assume it was also the resolution and refresh rate. I recommended to use a different monitor... I don't know what the result is yet.

[@--Zook--]

It was 32*c here today. I was outside in the heat for 11 hours with no break. Suck it up buttercup. JK by the way. love the vids.

[@pxidr]

A pregnant capacitor ^^

[@AmitChaudhry27]

Chris see your mail ease I sent two no reply and it's a awesome video