My HP Desktop Will Not Boot Or Power On (Continued)

[ADonMartini_790]

My HP Desktop Will Not Boot Or Power On

My original topic has been locked since my last visit, so I am being forced to open a new question to continue the discussion. After all, I did have to warn everybody that I'd be slow in responding due to personal matters. If anyone is able to unlock the original thread and merge the topics, please feel free to do so; again, I can't guarantee I can reply swiftly enough to prevent my topics from being locked next time, and it's awfully inconvenient to have to start new questions for the same subject each time.

In response to the last recent post from Riddle_Decipher, who had been trying to help me out on the original thread by suggesting I use an HDMI cable to attempt to connect a separate monitor to my All-In-One to do some troubleshooting, I just had a moment to try to do just that, but in examining the unit, I wasn't able to find an HDMI port to make that type of a connection; had about six USB ports, but not a single port for HDMI to be found, sorry to report. Worse yet, I tried turning the computer on for the first time in about four months, and it still isn't booting after being off for so long: only the fans kick up, but there's still no monitor display, and the power button isn't illuminated.

I guess my particular All-In-One device wasn't built with HDMI capabilities, so I couldn't try what was suggested to see if the problem is only limited to the display. Again, I did research before posting the original thread and found that other people have had the same problem with this time of device (links were provided), going back a number of years before it ended up happening to me in September. Since it looks as though this desktop will have to lie dormant in our household's tech morgue (I.E. our upstairs closet) waiting for eventual repair, I'll have to renew my plea to everyone here in the HP Support Community: if anyone has any idea what the problem is, or better yet, how to fix it, please don't hesitate to respond.

If anybody needs any additional information about the device, please let me know; again, I may not be very fast to reply, but I'll do my best to get back to you, even if that means I'd have to open another thread here to do so.

Thanks (again) in advance,

ADonMartini_790

[savvy2]

just post full  product ID # and full model first.  (300 tells me zero) AIO sure.

AIO tells me it is harder to fix than any real desktop is..... (dangling. prop....)😎 (has non standard PSU)

then post all evidence, next. focus 100% on all seen heard  or even felt.  (we can not see you PC over your shoulder. sorry😐

A dead PC has over 20 causes, and my listing all or guessing is fruitless. 😀 so I  teach testing, ( no free fish )

first unplug the PC from the wall AC jack,  for 1hour, push power button few time times like this to discharge all caps.

PCs all made can latch up from ESD or near lightning hits but never DIRECT (Tesla says so)"self protection"

then connect backup PC now dead cold and all rails PSU inside are now discharged put back the AC cord.

this is SOP 101  there, all PCs (if laptop remove the huge battery first, leave that thing out until PC runs right again)

now we push power button , AC cord back and the LED glows or blinks(bad) and is not dead. what does yours do, I can't see.

ok LED glows, and now sounds happen on all PCs desk. fans blow , heard, seen or felt blow. air.

IS the PC silent  if yes PC is dead,  we then work 100% Dead PC evidence only,   and 20 causes , and the strip down test.

Ok fans spin, wow it is not totally dead and omg the screen shows HP splash and you hammer the ESC key.

then  the BIOS screens show, and the BIOS INFO page is there, even with HDD missing this works, BIG Hint there.

the BIOS screens can be dead or lies to you  on configs there , or date wrong, the RTC coin cell battery is dead, and frankly  I test all that I see first. after all why would I  release any PC to others, and the battery dies next day , me egg on face.

I test them all, below 2.9vdc on any coin is a bad coin battery sold at walmart for a buck;./

like flow charts see this.

strip down testing any PC is tedious but must be done if any module in any PC shorts, USB unpugged first.

USB can in fact short out, worse cased is to shield Vbus  to shield boom PC dead.

the strip down is here , show an tell.

your PC has no HMDI out and the reason folks told you that is because you failed to tell exact mode of PC.

300 is NOT a PC ever, it has  a much longer model number and  a service tag

if you go to hp.com and it asks for the service tag, IT will , the HP.com will tell  you your exact model Product ID #

and that tells what is inside the PC,   (some mobo in those PC have not GPU ports at all, ) like yours.

any  PC repair shop on earth can fix this or diagnose it.

can you do my tests? only  testing works guessing will be very costly and huge waste of time;.

and Happy new year.

PS

and pleasee show all evidence first,  good bad  or ugly I call it.  tell all things you see and  hear, all.

for sure  pure silence.(dead fan) on no  beeps no flashing led , no text errors or HP slpash screens dead.

PS2

if the PC is dead the HP official diagnostics , boot media is useless.

[savvy2]

you did say the power lamp is  dead.

that is a power failure

do the long power reset.(told above)

wishI  I knew model number for me to learn  year.

age maters on all machines, of any kind

some parts last 100 years( transistors)  have some gear here 1968 runs like new, SS. (I restore Ham gear. too) 52 year old transceiver, HF. restored by me,  can have PCs here 2005 running w10-64b the HARD way ASK.

some 5years  some less .  (and batteries bad is top  of list bad on all things made, )

parts matter. APM all parts matter, and AGE is king there. and not told.

the screen is 100% dead. too, but power is dead so LCD can not work like that. ever.

NO PC told no PC told not yet.