A1990 820-01041-A no boot

[hgoncalves]

Hi, i have an A1990 820-01041-A that pulls 19.5v from charger, consumes about 50mA and the goes to 0A, and don't boot.

The client told that it started to say that it has no battery, and he replaced the battery but without success. Now it doesn't power on.

What should i measure from here?

 

[2informaticos]

Ask the client the exact steps he did when he changed the battery.

Check PPBUS_G3H, 3V3_G3H and other power rails w/ and w/o battery connected.
Did you test it in SMC bypass mode?

 

[hgoncalves]

The client says that he unpluged the battery and then take it out with a bit of isopropil alcool

I didn't test in bypass mode because don't know how to do it :-(

how can i do it?

PPBUS_G3H = 12.5v (w/o battery)

3V3_G3H = 3.3v (w/o battery)

PP1V8_G3S = 0v (w/o battery)

PPBUS_HS_CPU = 12.6v (w/o battery)

PPBUS_HS_GPU = 12.6v (w/o battery)

PPBUS_HS_OTH5V = 12.6v (w/o battery)

PPBUS_HS_3V3G3H_T 12.6v (w/o battery)

PPVCC_S0_CPU = 0v (w/o battery)

PP1V2_S3 = 0v (w/o battery)

PP1V05_PRIM = 0v (w/o battery)

_____________________________________________________

PPBUS_G3H = 12.5v (w battery)

3V3_G3H = 3.3v (w battery)

PP1V8_G3S = 0v (w battery)

PPBUS_HS_CPU = 12.6v (w battery)

PPBUS_HS_GPU = 11.8 ~ 12.6v (w battery)

PPBUS_HS_OTH5V = 12.6v (w battery)

PPBUS_HS_3V3G3H_T 11.8 ~ 12.6v (w battery)

PPVCC_S0_CPU = 0v (w battery)

PP1V2_S3 = 0v (w battery)

PP1V05_PRIM = 0v (w battery)

Are those enought? shell i check anything more?

 

[2informaticos]

Do not waste time measuring same power rail in different points!
PPBUS is PPBUS, no matters G3H, HS, or something else; use the logic and save time.

Mentioned behaviour was reported for missing battery.
Test the machine with known good working battery.
Be sure to connect it properly; tighten screw and data flex.

 

[hgoncalves]

Hi,

I've installed a new battery and the behavier is the same.

Any ideas?

 

[2informaticos]

"New" chinese battery?

 

[hgoncalves]

No, a good battery from a known good supllier from the UK (at least i think so).

Can i test it some how to make sure?

 

[2informaticos]

Only testing same battery in other machine, or "known good working" battery into your machine...

 

[hgoncalves]

Unfortunately, i don't have any other A1990 to try the battery or a known good working battery (but the problem happens with 2 different new batteries, from different suppliers).

Is anything more that i can try?

 

[hgoncalves]

shell i give up?