Power supply issues

[MeeTee]

Printing, then everything went dead. No lights, no LEDs, nothing, no sounds, except the power supply quietly "beeps," when plugged into the computer.  I'm way to deaf to hear it but Tim does hear it. Used digital volt meter and power supply is putting out 19.5 VDC, no load. Swapped it out for an identical 90 watt power supply from another computer. Still dead, nothing.

I just read about hard reset. Computer is at another location and I won't be back there until tomorrow.

On line forum says power supply was never equipped with any electronics that would allow it to beep? If it's beeping it's shot? Replacement power supply did not beep.

I tried with things unplugged, everything but the keyboard and mouse, still nothing.  If hard reset does nothing is there anything inside the case like a fuse link or something of that nature that might have burned out if the power supply died and sent errant current to the MB?

Other than board level repair is there anything I can do inside the case?

Thanks

Tom

I am no electronic dummy, but I know little about on board computer circuitry. I restore antique radios as a hobby.

[savvy2]

Great job so far. (is it only 3 years old>?)

your support page is here

https://support.hp.com/us-en/product/hp-pavilion-23-q100-all-in-one-desktop-pc-series-touch/8499724/...

Yes things can beep,  all PC beeped from 1981 forward, all did  and then some went to no beeps and just  flashing LED.

Caps lock LED is that now.  but beeps have codes, does yours beep in  patterned code?  (Sam.MORSE like)?

beeps really are the 1st thing ,with any dead pc of any kind...

what you own there is a laptop stuffed into a LCD screen case. (but no mobility)

Yes the mobo has regulators, yes, thing can short causing them to turn off, (no fuses,  needed the regs shut off overloaded)

There is no real ATX PSU there, it works like laptrop there, best i can tell.   real PSU dont beep sure.

yes most PC can beep,, about 1/2 all mobo made can beep.

 100% dead screen no text EVER !

the manual is here (not too good, imo)

http://h10032.www1.hp.com/ctg/Manual/c04717173

mobo page hp "the crusher" (wallet crusher sure)

https://support.hp.com/us-en/product/hp-pavilion-23-q100-all-in-one-desktop-pc-series-touch/8499724/...

 it is an ALL IN ONE PC,, a totally unique and non standard system.

Pavilion 23Q127C

HP Pavilion All-in-One - 23-q127c (true name)

It has its own odd PSU listed in the parts list, non standard inside (outside is simple 19v), and own non stardard MOBO, mother board. (each page there marked "custom"

that means , the spares we keep on real PC's dont work here, (like a real PSU etc) (hdd is the exception)

the parts list shows: "Power Board - Marcus, Amee, SunStre" and not stocked now.

the mobo shows "Motherboard - Crusher-U,S-Bay H81,UMA, W8Pro" and not stocked now. in the  hp parts surfer.
I see there are very few used parts sold for this PC,  not good sign, that. and some at scalpers prices due to rarity.

what can fail?, like and  radio, can fail (im a ham extra class and ex mil radio guy,++++) I restore those too. Heathkit +

Failure classes:

the power supplies can fail, the on board regulators can fail.

the power RAILs can short. (things attached) or ram SHORT.

the HDD can fail or short said rails. (rails means all DC power bus structures, rails (hot and common)

Symptoms:?

Not text? ever< no fan ever? no hdd spinsounds. no led inside glowing, no other indications of power there?

 fan spin.? and not packed full of lint, as most are? this old.

can you hear the HDD spin?  take it out and see if BIOS works now?  did you test BIOS first? see if  it;s  alive ????

Take things off the mobo that can short. see if power restores. 

to find this problem we strip the PC, so make sure all regulators work first. 

if we find a shorted device, it must be replaced. (stripping PCs is the only way to find shorts , due to bus structures.

some times it's not a simple device bad you can find or fix. and the mobo is shot.

What is hard on these machines is the lack of schematics or even a simple block diagram showing at least power structures.  (and test points)... lacking.... (per mil rules, cant be sold to Mil lacking that !)

 show and tell, day....

Here is your mobo.

as you can see there is not much there to play with,  ram on the left.

I dont think the RTC is bad, but $2?

new RTC coin cell tired first?  and if 2 rams, try each 1 at a  time, fan ok, does BIOS work with HDD pulled.

On some of these mobo is an LED on the mobo below, telling that power is there. (some)

that is all I have, on this.

[savvy2]

PSU 101:

if it was a real PSU

and it made a sound.?

here are the causes.

1. the fan is stalled/.bad , or its bearings bad and squeal, all bearing on earth can do that, failed. (a pure mech, issue)
2. the PSU has 20khz chopper inside, (called a SMPS) some folks or kids can hear 20,000 Hz.  not me , too many bombs in viet nam for me to hear that. 
3. An overloaded (but not too high to trip  that) the PSU will emit that 20khz, sound (at the top of human hearing rage)
4. NEWER PSU, use 40khz no human can here, (dog or birds and bugs. Ive no clue)
5. There may be 1 brand of PSU that has a Piezo electric warning beeper,  for overheat,  try to know there  are 100s of makers of PSU , and gaming high end PSU that have HUGE FEATURES listed,.,. so.....
6. On even newer PSU, the CAPs inside are glued down (hot glue or RTV) to keep them FROM SINGING !!!
7. The transformer too can sing, if bad or cheaply made or have loose windings.
8. To learn all this study SMPS designs.  (most will make noises overloaded)

but this is not what you own, you do not have a DESKTOP ATX class PSU. (BUT MAY HAVE  smps hidding deeper there)

but no ATX is there.  All Laptops have one hidden in the main mobo. It takes 19vdc and makes many more rail supplies.

also some PSU have a DC brushless fan, inside , it has  it's own  PWM chopper to drive its, 3 phase, AC motor,

and it to can sing if bad, or overloaded ,etc.

this should cover all ways to make noise on 1 boxed PSU. (ATX of any kind) PC's not servers.

as  you can see NOISE is a complex subject both sonically and electricial , radiated or conducted. complex topic.