Erica3 motherboard, lockup/reboot when air conditioning on/off

[GLerner]

Frequent lockup or reboot when power fluctuations. 
Most common power fluctuation is apartment air conditioning goes on or off.

Lockup is mouse & keyboard lights off and screen freezes and (if any audio is playing) audio loops.

Reboot vs lockup is random, about even occurrence. 

Nothing that seems related in the error logs. 

Isn't related to what programs I am running. It locks up or reboots whether I am in Brave browser, Atom editor, Zoom webinar, or any other software or combination of software. 

This has been happening for many months, from early May when started using air conditioning Phoenix-frequently through now October. 

Plus, the power supply occasionally makes rattling noise, lightly tapping the case stops the rattle. 

So, I conclude that the power supply has sub-standard capacitors to maintain steady input voltage; and the output voltage fluctuates outside the motherboard requirements. 

I do not want to pay the higher than normal price for an exact replacement since I think this power supply simply doesn't output consistent output voltages. 

Erica3 uses non-standard power connectors to the motherboard. Most connectors look like the connectors on, for example, Corsair or Thermaltake power supplies for an ATX motherboard; but not all. 

Therefore, I have no certainty that the (apparently) undocumented pinout and voltage for every connector is the same. 

What is the pinout and voltage for the Erica3 power connectors?

Is there an adaptor for the 7-pin (from top side, probably 6-pin on board side) connector?

Can I replace the power supply and motherboard, and still use the case? The motherboard is, in HP documentation, "Form Factor: Customized: 29.09 x 20.3 cm (11.45 x 7.99 in)"
I would re-use the AMD Ryzen 5 4600G CPU, M.2 SSD, 32GB RAM. 

original power supply Delta Electronics
HP P/N L76557-003
DPS-400AB-43 A rev 0C
6-3/8" x 2-5/8" x 3-3/4" (quick hand measurement) , mounted to case with 4 screws on power switch side
SysPwr 14" 360mm (approx) 4-pin Molex square with beveled pin plastic so only fit proper orientation, 
labeled on motherboard "SYS_PWR P1"
2x CPU Pwr 26" 660mm 4-pin Molex square with beveled pin plastic so only fit proper orientation, 
labeled on motherboard "CPU_PWR" (only 1 used)
6+2 or 8-pin PCIe 12" 305mm (unused, for graphics card, but many graphics cards need two of these)
7-pin labeled on motherboard "P2 PWRCMD" only pins 7,5,4 used
	maybe "7 pin 6 wire connector going into the motherboard labeled PWR CMD" https://www.techpowerup.com/forums/threads/power-supply-psu-pwr-cmd-help.273208/ "JST connector with a PH/2.0 mm spacing", probably 6 pin with one filled hole.
12.1V Main 18A
12.1V CPU1 18A
12.1V G1 18A

[OneThriftyMan]

You could get an inline AC Power "Line Conditioner" to prevent the sags or brownouts from ruining your day.

You will need to have a higher VoltAmp rating than your current power supply uses.

So for a 180 watt power supply with a 90% efficiency rating, it will consume up to 200w from the wall to deliver up to 180w to your pc.

Thusly, you'd want a Line Conditioner with at least a 250 VA rating.

The "Uninterruptable Power Supplies" / UPS is a little overkill here but would also provide a similar way to prevent the stutter.

For a UPS, you should NEVER get the cheapo version with a "modified sine wave" inverter. They will ruin your power supply.

Always get a pure sine wave inverter.

[GLerner]

Some (but not all) APC UPS models have Automatic Voltage Regulation (AVR). "Automatic Voltage Regulation (AVR) instantly corrects high/low voltage fluctuations so connected devices receive consistent power."

Some (but not all) APC UPS models have Filtering. "Filtering: Full time multi-pole noise filtering :5% of IEEE surge let-through : zero clamping response time"

For a computer, if you're going to use a Supplemental Power Supply (none are truly "uninterruptible") get one with AVR.

You have to Carefully check the data sheets on APC.com since APC doesn't have a search filter for whether models have AVR. 

I haven't finished searching, and really should have APC Support do the search, but the closest to "computer sized" I've found so far is: 

APC Back-UPS 1000, Compact Tower, 1000VA, 120V, AVR, LCD, 8 NEMA outlets (4 surge + battery, 4 surge)
model BX1000M

Then when you have the model you want, shop around for the best price. (Note: many UPSs on eBay the unit is good but the battery needs to be replaced, and even ones labeled as "no user replaceable battery" you can; open the case and the connectors are the same.) Just buy a new battery, not a battery that has been sitting on a shelf for years; battery quality really matters.

APC also has "Line-R 1200VA Automatic Voltage Regulator" and "Line-R 600VA Automatic Voltage Regulator" 
Models LE1200 and LE600

Hunt on eBay, most with shipping cost $60 to $90. I lucked out and found one for price + shipping + tax under $30. 

That should help this computer. I'll test it and see.

However, there are motherboards that use standard power supplies, from top-rated brands, that have better voltage regulation in the power supply than this Delta one.

I'm not going to buy another computer with an Erica motherboard or a Delta power supply.